Handbook of Zoology: Volume 1 Echinoidea 9783110368574, 9783110371703

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Handbook of Zoology Echinodermata Volume 1: Echinoidea

Handbook of Zoology Founded by Willy Kükenthal Editor-in-chief Andreas Schmidt-Rhaesa

Echinodermata Edited by Andreas Schmidt-Rhaesa

DE GRUYTER

Echinodermata

Volume 1: Echinoidea Edited by Heinke Schultz

DE GRUYTER

Scientific Editor Heinke Schultz Dorfstr. 32 25485 Hemdingen, Germany

ISBN 978-3-11-037170-3 e-ISBN (PDF) 978-3-11-036857-4 e-ISBN (EPUB) 978-3-11-038601-1 ISSN 2193-4231 Library of Congress Cataloging-in-Publication Data A CIP catalogue record for this book is available from the Library of Congress. Bibliografic information published by the Deutsche ­Nationalbibliothek The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available in the Internet at http://dnb.dnb.de. © 2015 Walter de Gruyter GmbH, Berlin/Boston Typesetting: Compuscript Ltd. Printing and Binding: Hubert & Co. GmbH & Co. KG, Göttingen ∞ Printed on acid-free paper Printed in Germany www.degruyter.com

Foreword Sea urchins (class Echinoidea) belong to the phylum Echinodermata together with sea lilies (class Crinoidea), starfishes (class Asteroidea), brittle stars (class Ophiuroidea), and sea cucumbers (class Holothuroidea). Their calcite skeleton provided them with an excellent fossil record since they first evolved, some 450 million years ago. Today, this highly diverse and very successful group of marine invertebrates is distributed from the tropics to the poles and from the intertidal zone to the deep sea down to more than 5,000 m. About 900 species are described to date. To most people, echinoids are known as decorative skeletons in souvenir shops or from eating their gonads as sushi. Beachcombers, snorkelers, and divers enjoy their bizarre forms or beautiful colors – or they keep longlasting impressions after having touched the sharp and sometimes venomous spines.

For ecologists, echinoids are an important component of the marine benthic community with conspicuous influence in complex food webs regulating the diversity and abundance of plants and animals. The focus of this book is to give an overview on described echinoid species and represent them with images. Short chapters give an introduction into the biology, ecology, and phylogeny. This is the first of two volumes, and it deals with pentameral (regular) echinoids; a second volume on the bilateral (irregular) species will soon follow. The two volumes were generated from a book publication: Sea Urchins: A Guide to Worldwide Shallow Water Species (published in 2005 by Heinke & Peter Schultz Partner Scientific Publications), followed by the supplement volumes: Sea Urchins II. Worldwide Irregular Deep Water Species (2009) and Sea Urchins III. Worldwide Regular Deep Water Species (2011). All these three volumes had a limited distribution and are out of print.

Contents Foreword

4.2.2.1

v

Abbreviations

ix

1 1.1

Introduction and general morphology Body plans of major groups of sea urchins 1 1.2 General morphology 1 1.2.1 External appendages 6 1.2.2 Internal organs 6 1.2.3 Digestive system 6 9 2 Echinoid biology 2.1 General biology 9 2.1.1 Locomotion 9 2.1.2 Respiration 9 2.1.3 Defense, predators, and camouflage 2.1.4 Feeding 10 2.1.5 Human consumption 11 2.2 Reproduction 11 2.3 Growth 13 2.4 Evolution and phylogeny 14 3

Classification and systematics

1

10

21

23 4 Taxonomy: systematic descriptions 4.1 Subclass Cidaroidea Smith, 1984 23 4.1.1 Order Cidaroida Claus, 1880 23 4.1.1.1 Family Cidaridae Gray, 1825 23 4.1.1.2 Family Histocidaridae Lambert, 1900 126 4.1.1.3 Family Psychocidaridae Ikeda, 1936 133 4.2 Subclass Euechinoidea Bronn, 1860 135 4.2.1 Order Echinothurioida Claus, 1880 135 4.2.1.1 Family Kamptosomatidae Mortensen, 1934 136 4.2.1.2 Family Phormosomatidae Mortensen, 1934 136 4.2.1.3 Family Echinothuriidae Thomson, 1872a 139     Infraclass: Acroechinoidea 157 4.2.2 Order Aspidodiadematoida Kroh & Smith, 2010 159

Family Aspidodiadematidae Duncan, 1889 159 4.2.3 Order Diadematoida Duncan, 1889 167 4.2.3.1 Family Diadematidae Gray, 1855 167 4.2.4 Order Micropygoida Kroh & Smith, 2010 187 4.2.4.1 Family Micropygidae Mortensen, 1904 187 4.2.5 Order Pedinoida Mortensen, 1939 189 4.2.5.1 Family Pedinidae Pomel, 1883 189 Carinacea Kroh & Smith, 2010 195 4.2.6 Order Salenioida Delage & Hérouard, 1903 195 4.2.6.1 Family Saleniidae L. Agassiz, 1838 195 4.2.7 Order Stomopneustoida Kroh & Smith, 2010 201 4.2.7.1 Family Glyptocidaridae Jensen, 1981 201 4.2.7.2 Family Stomopneustidae Pomel, 1883 201 4.2.8 Order Arbacioida Gregory, 1900 203 4.2.8.1 Family Arbaciidae Gray, 1855 203 4.2.9 Order Camarodonta Jackson, 1912 218 4.2.9.1 Family Parasaleniidae Mortensen, 1903 219 4.2.9.2 Family Temnopleuridae A. Agassiz, 1872 221 4.2.9.3 Family Trigonocidaridae Mortensen, 1903 264 4.2.9.4 Family Echinidae Gray, 1825 274 4.2.9.5 Family Echinometridae Gray, 1825 291 4.2.9.6 Family Parechinidae Mortensen, 1903 316 4.2.9.7 Family Strongylocentrotidae Gregory, 1900 324 4.2.9.8 Family Toxopneustidae Troschel, 1872 333 Literature

359

Acknowledgments Glossary Index

369 375

367

Abbreviations In the text, museums or collections are abbreviated. The following abbreviations were used: AWI  Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany MfN  Museum für Naturkunde, Leibniz-Institut für ­Evolutions- und Biodiversitäts-Forschung, Berlin, Germany NHM  Natural History Museum, London, UK NIWA National Institute for Water and Atmospheric Research Ltd., Wellington, New Zealand ZMUC Zoological Museum, Natural History Museum of Denmark, University of Copenhagen, Denmark ZMH  Zoologisches Museum, Centrum für Naturkunde, Hamburg, Germany ZSM  Zoologische Staatssammlung München, Germany

1 Introduction and general morphology Sea urchins, Echinoidea, belong to the Echinodermata. The other four classes of this phylum comprise the sea cucumbers (Holothuroidea), sea lilies (Crinoidea), starfish (Asteroidea), and brittle stars (Ophiuroidea). ­ They live exclusively in marine environments from the poles to the equator and from intertidal zones to depths of more than 5,000 m. Fossil echinoids date as far back as the Late Ordovician Period, about 450 million years ago. Superficially, extant sea urchins can be divided into two groups: the “regulars”, with a circular test and pentameral symmetry living on the sediment (Fig. 1.1 A), and the bilaterally symmetrical “irregulars”, mainly living in the sediment (Fig. 1.1 B). The regulars itself consists of two subclasses, separated by fundamental differences in morphology and phylogeny, the Cidaroidea (Fig. 1.2) and the Euechinoidea. Besides the somewhat strange Echinothurioida (“leather urchins”), the regular Acroechinoids (Fig. 1.3), with eight orders, and the irregular Acroechinoids (Irregularia), with six orders (Figs. 1.4 and 1.5), belong to Euechinoidea.

A

1.1 Body plans of major groups of sea urchins The calcareous shell of the sea urchin (test or corona) is built of ten double columns of plates: five in the ­ambulacra (white), perforated by one or more pairs of pores or single ones, and five in the alternating interambulacra (shaded in blue). The perforated ambulacra (A) are labeled from I to V; the interambulacra (IA) are labeled from 1 to 5 (see Figs. 1.2 and 1.3). In irregular echinoids, this principal plan is modified and the test is bilaterally symmetrical with two equal sides (see Figs. 1.4 and 1.5). The anus has moved from the upper side out of the apical system to the posterior or oral side.

1.2 General morphology Echinoids have a hollow, more or less globular test built by an internal skeleton covered by a skin. The plates of

B

Fig. 1.1: (A) Regular sea urchin with pentameral symmetry. Echinus gilchristi Bell, 1904. (B) Irregular sea urchin with bilateral symmetry. Metalia spatagus Linné, 1758.

2 

 1 Introduction and general morphology

madreporite

apical system

A III

A III genital plate

IA 2

IA 3

IA 3

IA 2 ambulacrum

ocular plate A II

A IV

A IV

A II peristome

IA 1

IA 4

IA 4 IA 1

periproct AI

AV

interambulacrum

AV

AI IA 5

IA 5 upper side aboral

underside oral

Fig. 1.2: Regular sea urchin: diagrammatic plan of a Cidaroid.

A III

apical system

IA 2

IA 3

genital plate

A III

madreporite

IA 3

IA 2 ambulacrum

A II

A IV

A IV

A II

peristome IA 1

IA 4 ocular plate

IA 4 IA 1

AV

AI

interambulacrum

IA 5 upper side aboral Fig. 1.3: Regular sea urchin: diagrammatic plan of a regular Acroechinoid.

AI

AV IA 5 underside oral

1.2 General morphology 



madreporite = fused genital plates

interambulacrum

A III apical system

A III

peristome IA 3

IA 2

IA 2

IA 3

 3

ambulacrum A IV

A II

A IV

A II

IA 1 IA 1

IA 4 petals

ocular plate

IA 4

periproct AI

AV

AV

AI

IA 5

IA 5

upper side aboral

underside oral

Fig. 1.4: Irregular sea urchin: diagrammatic plan of a Clypeasteroid (“sand dollar”).

madreporite

apical system

interambulacrum

A III

peristome IA 2

IA 2

IA 3

A III

phyllodes IA 3

ambulacrum A IV

A IV

A II

A II

genital plate

IA 1

IA 4

petals

ocular plate

IA 4

IA 1

AV

AI

periproct

IA 5

upper side aboral Fig. 1.5: Irregular sea urchin: diagrammatic plan of a Spatangoid (“heart urchin”).

AV AI IA 5 underside oral

4 

 1 Introduction and general morphology

A

B

Fig. 1.6: (A) Regular Acroechinoid: upper side (aboral), the columns of plates radiate from the apical system. Lytechinus variegatus (Lamarck, 1816). (B) Underside (oral): the columns of plates converge at the peristome. In the center opens the mouth with the teeth (called “Aristotle’s lantern”). Gracilechinus elegans (Düben & Koren, 1844).

the ten double columns are equipped with one or more tubercles of various sizes, which carry spines or other specialized structures. On the upper side (aboral, Fig. 1.6), the apical system is positioned. It is composed of up to 10 plates, 5–2 genital plates, penetrated by gonopores, from which eggs or sperm are released during spawning, and five ocular plates. One genital plate is a more or less densely perforated sieve plate (madreporite). Through the pores of the madreporite, the internal water vascular system is connected to the exterior. The five ocular plates at the summit of each ambulacrum are pierced by a single tube foot, which is the terminal extension of the radial water vessel (Fig. 1.8). The periproct within the ring of apical plates is in life covered by a flexible membrane, with the opening of the anus more or less in the center (Figs. 1.2 and 1.3). In irregulars, the ambulacral pores are concentrated on the aboral side in leaf-shaped areas (petals); on the oral side, they are crowded around the mouth (phyllodes)

or in well-defined fields. In heart urchins, the peristome has shifted to the anterior, while the posterior interambulacrum is strongly elongated. The surface of the test is densely covered by more or less uniform tubercles set with small fur-like spines (Figs. 1.4 and 1.5). The columns of plates converge on the oral side, opposite to the apical disc, at the mouth (peristome). In life, the peristome is covered by a flexible membrane with embedded platelets of variable size and density. In cidaroids and echinothurioids, the double series of ambulacral plates with pore pairs continue over the peristome to the central mouth. Between these rows, there may be non-ambulacral plates. In all other regular groups (Fig. 1.6 B), the peristomial membrane has only five pairs of buccal plates, each bearing one single tube foot. The remainder of the membrane is more or less scattered with small platelets. The mouth opens in the center of the peristomial membrane. All regular groups of echinoids have external teeth, which form part of a rather

▸ Fig. 1.7: External appendages. (A) Wormlike tube feet (podia) are arranged in two rows in each ambulacrum, protruding from the pore pairs.

Their thin walls function as a surface for gaseous exchange. Their distal end is developed as a sucking disc and contains sensory organs. The tubes of the podia are very extensible. Parechinus angulosus (Leske, 1778); test diameter with spines, 45 mm; Cape Town, South Africa. (B) Penicillate tube feet with many finger-like digits are positioned in the oral ambulacra picking up food particles and directing them into the mouth (upward). Scale: 5 mm. Amphipneustes bifidus Mortensen, 1950. (C) The median area of the ambulacra is set with numerous whitetipped pedicellariae, which have poison glands developed at the base of their thick valves. Scale: 2 mm. Tripneustes ventricosus Lamarck, 1816.

1.2 General morphology 



A

C

B

 5

6 

 1 Introduction and general morphology

complicated jaw apparatus, called “Aristotle’s lantern” (or simply “lantern”) (Fig. 1.9). In the irregular cassiduloids, teeth are only found in very young specimens; in adults, they are lost; in ­clypeasteroids, they are modified to internal grinding organs, and in the Atelostomata, they are completely absent.

1.2.1 External appendages The body surface of sea urchins is equipped with a variety of appendages: the spines, made of calcite, are very conspicuous. Each of them is connected to the test by a muscular collar, and is articulated to a round tubercle. Other connecting tissues can lock the spine erect. Once this tissue is activated, it is easier to break the spine than to move it. In cidarids, there are a few large primary spines, which are encircled at the base by a palisade of secondary spines. The cidarid spines have an outer layer of calcite, and they are more or less overgrown by foreign organisms, foraminifers, sponges, small molluscs, etc. In all other echinoids, the mass of primary, smaller secondary and tiny miliary spines is covered by living skin and never becomes encrusted. The tube feet (podia) (Figs. 1.7 B and C) are delicate tubes of soft tissue, which penetrate through two small holes from the inner of the test, where they are c­ onnected to the water vascular system. They are very extensible and move hydraulically. The podia may end distally with a suckered disc or in finger-like processes. They are used for locomotion, sensory perception, respiration, and the manipulation of nearby objects. The pedicellariae (Fig. 1.7 A) are tiny, stalked, pincerlike valves, more or less densely scattered among the spines. They serve to ward off small organisms or predators by means of sharp teeth and/or poison glands and to keep the surface of the test clean. The various shapes of these microscopic structures are important for distinguishing species. The buccal sacs emerge at the peristomial edge (buccal notches) of the interambulacra. Five pairs are arranged around the mouth. They are direct extensions from the internal body cavity and compensate for internal volume changes when the jaws are moved in and out of the rigid test. In former times, they were thought to be gills for respiration.

The sphaeridia are microscopic, stalked, club-shaped structures on the underside of the test and are developed in all echinoids except of Cidarids. They are thought to act as organs of balance.

1.2.2 Internal organs The water vascular system (Fig. 1.8) consists of a tube connected through the pores of the sieve plate (madreporite) to the exterior. It leads downward to the ring canal, which encircles the lower part of the intestine coming from the mouth. From the ring canal, five branches (radial canals) radiate, underlying the median suture of the ambulacral plates. Ampullae are attached to the radial canals and joined through a pore or a pair of pores to the external tube feet. Each radial canal ends in a single ocular tentacle, piercing through the ocular plate in the apical system. The hemal system is a type of “blood” circulatory system. The main tubes roughly follow the water vascular system and the gut, but give rise to branches that reach the gonads and other internal organs to supply them with nutrition. The spongy axial organ is involved with functions of the hemal system, but what precise function it may have is not clear.

1.2.3 Digestive system The tube-like esophagus emerges from the top of the jaw apparatus (if present) and leads to the stomach. The stomach leads into an intestine that performs a loop inside the test and back again forming a second loop. The latter ends in the anus that exits through the center of the periproctal membrane (Fig. 1.10). The gonads are five (in regulars) to two (in some ­irregulars) interradially placed organs, which are each connected by a gonoduct to the genital pore (gonopore) in the corresponding apical plates. The sexes are separate. A central nervous system is lacking; there are neither ganglia nor a brain. Nevertheless, all echinoids have an extensive subepithelial net of nerves that serve in ­coordination of external appendages and sense reception. Nerve tracks around the gut and associated with the internal organs allow echinoids to coordinate locomotion, ­nutrition, sensation, and reproduction.

1.2 General morphology 



madreporite

 7

ocular tentacle

ocular plate internal ampullae

pore pair

ambulacral

ring canal test

external tube feet radial canals

peristome Fig. 1.8: Schematic drawing of the water vascular system.

A

epiphysis

opening for esophagus

B

Aristotle´s lantern epiphysis muscles

pyramid = two demipyramids

teeth

perignathic girdle

auricle

Fig. 1.9: Aristotle’s lantern (jaw apparatus) of camarodont echinoid. (A) Internal view of lantern: the muscles for moving the lantern are connected to the perignatic girdle. (B) The lantern is built of five pyramids ( = 10 demipyramids), which are overbridged by the epiphysis to strengthen the construction in camarodonts. Height of lantern 28 mm (Pseudoboletia maculata).

8 

 1 Introduction and general morphology

madreporite

anus

gonopore

axial organ gonade

stone canal

stomach

test

intestine

esophagus

jaw apparatus (= lantern of Aristotle) peristome

teeth

Fig. 1.10: Digestive system of sea urchins (modified after Storch & Welsch 1994).

buccal sac

2 Echinoid biology 2.1 General biology

2.1.1 Locomotion

According to the differences in shape, regular and irregular sea urchins differ considerably in lifestyle. While the former live epifaunally, on rocks or solid sandy bottoms, the latter are mostly found infaunally, among gravels or in sands or even mud.

Sea urchins generally use their oral spines for locomotion. Regulars move in any direction according to their pentameral symmetry, while the sensitive, highly extendable tube feet examine the vicinity (Fig. 2.1). They are able to hold onto vertical walls and “climb” on steep rocks using the sucking discs of their tube feet. All sea urchins, except the members of the family Arbaciidae, are able to right themselves by means of their tube feet, when waves have overturned them. The irregular echinoids are unidirectional, they move forward with ambulacrum III forward and leading. With the help of strong, often spatulate spines, they plough or burrow through the sediment (Fig. 2.2 A). In contrast to the regulars, they usually have short, dense, overlapping spines to prevent sediment from falling onto the test and so maintain a water-filled gap around themselves.

Fig. 2.1: The greatly expanded tube feet (white arrows left) in the five ambulacra explore the vicinity of the animal. The surface of the upper side is densely covered by pedicellariae, the valves of which have developed small blisters, filled with poison. Tripneustes gratilla Linné, 1758 Safaga, Egypt, Red Sea (photo by H. and I. Rauch).

A

2.1.2 Respiration Respiration takes place mainly across the thin walls of the tube feet. Fluid is constantly circulating from the internal ampullae through one pore into the external tube feet and back through the other pore. In epifaunally living regular

B

Fig. 2.2: (A) An irregular echinoid is going to burrow into the sediment. Metalia spatagus Linné, 1758, Bohol, Philippines. (B) Many sea urchins cover their upper side with organic debris or small gravel particles, which the suckered discs of the tube feet hold tight. This way, the animals camouflage themselves to protect their tests against direct light. Sphaerechinus granularis (Lamarck, 1816), Turkey (photos by H. Moosleitner).

10 

 2 Echinoid biology

sea urchins, the efficiency of the “normal” suckered podia is sufficient. Irregular echinoids, which live in sediment, where oxygen is less available, have developed specialized podia with enlarged surfaces and extremely thin walls to increase respiratory efficiency. These tube feet are concentrated in leaf-shaped areas (petals) on the adapical side. Many groups are equipped with bands of tiny ciliated spines (fascioles), which create, through coordinated motion, a current of oxygen-rich water over the petals and ventilating the entire surface. Waste water is directed to the rear of the animal, where other fascioles wash it into the sanitary funnel, together with fecal material.

2.1.3 Defense, predators, and camouflage In regular echinoids, the dense and spiky spines are used for defense. In cidarids, the large interambulacral plates are set with large primary spines. The alternating ambulacra are narrow, and the plates carry small secondary spines covering and protecting the delicate podia of the pore zones, which are arranged in one pore pair per plate. In the regular Acroechinoidea, the ambulacral plates are fused to larger compound plates providing space for larger secondary spines. On the other side, the primary spines become smaller and much more numerous, and therefore, the sea urchin gets a better all-round defense. In echinothurioids, the needle-like spines have large, fleshy sacs at their distal end, which contain a very effective poison. In addition, they are equipped with numerous large pedicellariae with sharp teeth. In the family Toxopneustidae, the valves of the pedicellariae themselves have poison glands, which are powerful enough to repel large predators like sea stars, hence their name. Using their aboral suckered podia, many groups cover themselves with pieces of algae or shells for protection against light (camouflage) (Fig. 2.2 B). The camouflage may help avoid predation, as the sea urchin is hidden below a cluster of dead debris. In cidarids, the setting of foreign organisms on the spines may also have a masking effect, but some of them try to avoid over-heavy settling by the development of fine hairs and thin, sharp thorns. One sponge is able to remove the calcium from cidarid spines, which become soft and useless and fall off. All echinoids have an astonishing capacity for healing wounds and regenerating parts that are damaged or lost. Fish, birds, crabs, and even snails with their soft body are the main predators of spiny echinoids. An example, the large gastropode Cypraecassis rufa Linné, 1758 emerges a cushion of mucus on which it creeps over the sharp, finely thorny spines. Then it leads its snout

Fig. 2.3: A large gastropod preys upon a diadematoid sea urchin by means of a mucus cushion against the sharp spines. Length of snail 18 cm. Cypraecassis rufa Linné, 1758, Lembeth strait, Sulawesi, Indonesia (photo by R. Kraft).

through the spines to the surface of the test, drills it, and discharges the animal (Fig. 2.3). Irregular sea urchins avoid predators by living “out of sight”. But certain predacious snails search out buried urchins and feed on them, drilling through the test with their radula. Consequently, some irregulars have developed thickened tests or long spines at the aboral side for defense.

2.1.4 Feeding Regular echinoids graze with their sharp teeth on sessile organisms such as algae or sea weed, hydroids, foraminifers, sponges, or young echinoderms. They bite off pieces of algae, which are then manipulated into the mouth with help of the circum-oral tube feet. Irregulars are primarily deposit feeders, feeding on the fine organic material (detritus) that has sunken to the sea bottom. The flat sand dollars, the Clypeasteroida, prefer the detritus-rich layer just beneath the sediment. While the uppermost sand is transported over the test – the dense spine canopy making sure grains do not fall onto the test skin – enormous numbers of tiny oral tube feet on the oral side pick up small particles encrusted with organisms. These particles are placed into the food grooves, where they are moved by small spines like on a “conveyor belt” toward the mouth. Cassiduloids swallow large quantities of sediment for its relatively poor organic content. The indigestible sand is continuously discharged from the anus. In spatangoids, the podia concentrated around the mouth are equipped with many finger-like appendages (Figs. 1.7 and 2.12 A). They are able to pick up selectively organic particles from the sediment in their burrow.

2.2 Reproduction 

Other penicillate tube feet, situated at the center of the upper side, collect food from the surface of the sea bottom, bring it down a vertical funnel and place it into the deep furrow of the anterior side of the test. Mucus-producing spines transport the particles down to the mouth isolated from the surrounding sand by an arc of larger spines.

2.1.5 Human consumption The gonads of the sea urchins have been eaten by humans since prehistoric times. In some tropical regions, they are an important component of diet. In Japan and other countries, they are considered as delicacy, and they are harvested on a large scale in Chile or along the west coast of America. But the stock has already greatly diminished, and overfishing can radically change the ecosystem, as the grazing echinoids control the growth of the algae. Consequently, aquaculture of sea

 11

urchins has developed in recent years, with the trend to rear specimens with more uniform and more attractively colored gonads.

2.2 Reproduction In echinoids, the sexes are separated. According to the group, they have 2 to 5 gonads, which open through the gonopores in the genital plates. The males release the sperm and then the females disperse the tiny eggs into the open water, where the eggs are fertilized. In temperate climatic zones, spawning is often triggered by the temperature, and there exist annual cycles; in the tropics, spawning occurs more often. The tiny embryo grows into a transparent larva (“echinopluteus”) with two or more movable arms, supported by calcareous rods and bordered by ciliated bands for food collection and locomotion (Fig. 2.4 A–D).

D

A

C

B Fig. 2.4: (A–D) Echinopluteus larvae: (A) Eucidaris thouarsi, about 1.5 mm. (B) Diadema antillarum, 10 mm. (C) Clypeaster humilis, about 0.8 mm. (D) Lovenia elongata, about 2.5 mm (A, Mortensen 1928; B–D, Mortensen 1931). The arms of the transparent larva are bordered by short, dense bands of tiny hairs, the cilia. The coordinated beating of these cilia causes the locomotion. The bilaterally symmetric larvae have developed a mouth, a gut, and an anus, and they feed actively on planktonic organisms.

12 

 2 Echinoid biology

A

B

Fig. 2.5: Fibularia japonica, Central Japan, Pacific: sexual dimorphism. (A) The female has four large gonopores (length of female, 5 mm). (B) The male has small gonopores (length of male, 5.5 mm).

The larva lives in the plankton, actively feeding on microorganisms (a condition termed “planktotrophic”). But they are also prey for other animals. This stage can last some days or up to some months, and the larva drifts widely with the sea currents. Then it sinks to the sea floor and undergoes a complicated metamorphosis, radically changing its morphology from bilateral to pentameral symmetry and consequently changing its lifestyle from a pelagic filter feeder to a benthic grazer or infaunal detritus feeder. About two thirds of all living species develop through a larval stage, but in various echinoids belonging to different orders, more specialized modes of reproduction have evolved. The females release fewer but larger eggs, which are filled with yolk, the nourishment during the development of the young. Having no mouth or anus, they are not able to feed (“lecitotrophic”). After being fertilized by the male sperm, the embryo grows directly into a small sea urchin. The larval stage and the metamorphosis are more or less abbreviated or completely lacking. In these species, the difference between the sexes (“sexual dimorphism”) is visible (Fig. 2.5 A, B). The females have distinctly larger gonopores than the male.

Thus, there are principally two different strategies for reproduction: 1. Millions of tiny eggs develop into actively feeding echinopluteus larvae, which drift far away before they sink down onto a suitable substrate, undergoing metamorphosis. The great majority of them are preyed on by other animals in the plankton. 2. Relatively few, large, yolky eggs develop to non-feeding embryos with either rudimentary or no larval features. They stay only for very few days in the plankton before becoming sessile and passing through a largely abbreviated metamorphosis or they are housed in the brood pouches of the female until they are able to feed independently. The distribution of these juveniles is restricted, but a large number of them survive. Additionally, there occur intermediates, e.g. in the abbreviated larval stage of Heliocidaris erythrogramma ­(Williams & Anderson 1975). In some groups of directly developing sea urchins, brood protecting has evolved; the young are attached to or, even more sheltered, held inside the body of the female parent. This mode of reproduction is particularly common in Antarctic species, but it also occurs in some

2.3 Growth 

A

 13

B

Fig. 2.6: Amphipneustes marsupialis. (A) Aboral side of a female, test length 54 mm; Weddell Sea, Antarctica. In the broad, deep brood pouches of the female, the young grow up beneath a layer of spines. The eggs are hidden in the lowermost corner, the older juveniles lie between the spines. (B) Eggs and embryos. The young occur in three stages, as eggs, short-spined embryos, and long-spined juveniles. The latter are almost ready to leave the mother. Test diameter of a large juvenile, 3.3 mm.

tropic species. In Antarctic schizasterids, the young grow very slowly in deep brood pouches (marsupia), living on the yolk from the egg (Fig. 2.6 A, B). In the well-studied Abatus cordatus, endemic to the Kerguelen Islands in the southern Indian Ocean, this stage lasts 8½ to 9 months. Then the young are able to feed actively and they leave the female (Magniez 1979, 1983). In brood-protecting cidarids – the predominant number of them also from Antarctica – the juveniles are housed in a recess created by the flexible peristomial membrane. The eggs are manipulated from the gonopores in the apical disc to the underside by means of pedicellariae and small spines, being fertilized on the way (Barker 1984, Goniocidaris umbraculum). In Austrocidaris, the embryos are held on the depressed apical disc. The two most advanced modes of reproduction have developed in the Antarctic, too. In Aporocidaris incerta, the reproduction apparatus has been strongly altered: the gonoducts do not lead from the gonads to gonopores piercing the genital plates in the apical disc to emerge eggs or sperm. In females, the gonoducts end in large pores in the interambulacral median sutures on the oral side or even at the edge of

the peristome. In males, relatively small gonopores are transferred halfway down the interambulacral midline (Mortensen 1909, 1928, Lockhart unpublished PhD thesis 2006) (see page 78). It is self-evident that the position of the gonopores on the oral side is advantageous for the success of reproduction because the perilous transfer of the eggs from the gonopores on the apical side to the brood chamber on the peristome is avoided. In the holasteroid Antrechinus mortenseni, Family Urechinidae, the apical plates are modified in invaginating to an inner chamber, into which the fertilized eggs are deposited. Here they grow, in staggered stages, nourished by the initial yolk in the egg. When the embryos are fully developed, the center of the apical disc opens to let the young pass into the free water (Mooi & David 1996).

2.3 Growth As a sea urchin grows, new plates are added at the outer edge of the ocular plates (Fig. 2.7). In very young specimens, the apical plates cover the whole upper side, but

14 

 2 Echinoid biology

A

B

Fig. 2.7: Growth of echinoids. (A) The apical system of the young Echinometra mathaei is very large relative to the size of the test. Scale: 4 mm. (B) New plates are created at the outer edge of the ocular plates of Prionocidaris, the ambulacral plates in the center, and the two adjacent interambulacral ones at either side (arrows). The plates grow in size and are incorporated into the columns (right arrow). Scale: 10 mm.

as growths proceeds, the apical system becomes smaller relatively to the size of the test. The plates themselves increase in size, showing more or less concentric growth rings, only exceptionally visible. Depending on variable rates of growth at the edges, the shape of an individual plate is formed and consequently the shape of the test between the apical system and the peristome. In irregular echinoids, the periproct of very young specimens still touches the apical system, but it shifts during growth to the rear or to the oral side. A sea urchin is considered mature when the gonopores have broken through the genital plates, although the adult still grows considerably in size. Most echinoids live several years. However, in colder water, they have a longer life expectancy: e.g. Sterechinus neumayeri from the Antarctic Weddell Sea may live 75 years (Brey 1991).

2.4 Evolution and phylogeny Echinoids first appear in the Upper Ordovician, about 450 million years ago. Various forms with flexible, imbricating plates evolved (Fig. 2.8 A, B). They had tube feet for gathering food, which was scooped into the mouth by the teeth. By the end of the Palaeozoic, the group had dangerously declined in diversity. Only two lines with very few species survived the Permian-Triassic crisis: the miocidarids and the triadocidarids, from which later in the Triassic, the first modern Euechinoidea evolved. In the Lower Jurassic, echinoids

underwent a spectacular adaptive radiation, many diverse forms arose, which occupied various ecological niches. The cidarids (Fig. 2.9) are an offshoot of late Palaeozoic miocidarids, and thus, the oldest extant group with the most primitive features – but not at all a “model in decline”. In Antarctica, they were able to develop one of the most advanced modes of reproduction, brood protecting. With more than 120 Recent species, they are still “successful”, living on hard grounds like coral blocks or boulders or on solid sandy bottoms in relatively sheltered waters – much the same ecological niche as in the Triassic. There was “no need” to change their morphology. The cidarids are the sister-group of the Euechinoidea, which comprises the echinothurioids, a rather peculiar group with flexible, imbricating plates and some other features of former, Palaeozoic echinoids – and the Acroechinoidea. The acroechinoids include today approximately three quarters of all sea urchins. They are divided into three major groups, the regular Diadematacea and Echinacea and the Irregularia. As in the cidarids, the constructional plan of the regulars has remained remarkably “stable” since the Upper Triassic or Lower Jurassic. Their pentamery allows them to move on their oral spines in all directions, while the sensory tube feet explore the nearby environment. The feces, released from the periproct on the upper side, are washed away by water currents. Acroechinoids have principally the same lifestyle as at the start of their evolution, which is restricted by the balance among the five virtually identical sections of the test.

2.4 Evolution and phylogeny 



A

 15

B

Fig. 2.8: Early forms of echinoids. (A) Hyattechinus pentagonus Jackson, 1912. Aboral side, diameter 49 mm; Lower Carboniferous, Pennsylvania, USA (cast of an external mold, coll. HVT). The broad interambulacra are covered with many columns of imbricating plates. The ambulacra are very narrow. (B) Lepidesthes wortheni Jackson, 1896. Aboral side, diameter 38 mm; Lower Carboniferous, Indiana, USA (coll. HVT). The ambulacra are broad and set with numerous pore pairs. There are three columns of plates in each interambulacrum.

A

B

Fig. 2.9: Fossil Cidaroids. (A) Paracidaris jeanneti (Lambert, 1924). Aboral side, test diameter 18 mm; Upper Triassic, Hindelang, Germany (coll. HVT). (B) Stereocidaris sceptrifera. Oral side on a piece of chalk, diameter 28 mm; Upper Cretaceous, Criel, Normandy, France (photo by H. Friedhoff). Paracidaris lived approximately 200 million years ago, Stereocidaris 70 million. Both cidarids show the same morphology as Recent forms: few prominent tubercles with large areoles in the broad interambulacra, the ambulacra being very narrow.

Changes or “improvements” were relatively small and took place mainly with respect to nutritional, respiratory, and defensive functions: in the teeth, in the ambulacral plating with their pores and in the shape and arrangement of the spines and the tubercles.

In cidarids, the solid-plated test gives the necessary rigidity for the strong muscles of the jaw apparatus – Aristotle’s lantern – and the teeth were used for a more powerful plucking or rasping. Acroechinoids developed both lighter and more maneuverable lanterns

16 

 2 Echinoid biology

A

B

diadematid “aulodont

Cidaroida

Diadematacea

“stirodont

“

cidarid

camarodont

Carinacea

“

Fig. 2.10: (A) Evolution of Aristotle’s lantern: cidarids and “diademataceans” have teeth with an U-shaped cross section. The Carinacea evolved mechanically stronger keeled (or T-shaped) teeth, at first more simple typs (“stirodont”, term no longer in use). Later in evolution in the Camarodonta the plates of the jaw apparatus (pyramids) are connected by a bow (epiphysis), which further increases their strength. Cross sections of teeth are shown in solid black (after A. B. Smith 1984). (B) Acroechinoid regular echinid. Phymechinus mirabilis L. Agassiz, 1846. Aboral side, diameter 41 mm. Upper Jurassic (about 160 million years), France: in ambulacra and interambulacra, two series of subequal tubercles are developed, which in life would have been set with numerous spines for defense.

that allow them to take advantage of new food sources and therefore to colonize previously unexploited habitats. Another innovation comprises the ambulacral plating. The regular Acroechinoidea developed compound ambulacral plates with more space for larger secondary spines, and therefore a better all-round defense. The number of pore pairs did not decrease essentially. The four orders, formerly summarized under the name Diadematacea (see Chapter 4.3.), and echinaceans are distinguished by their lantern. The mechanically stronger, keeled teeth (stirodont) of the latter must have given them an advantage over the diademataceans with their “aulodont” jaw apparatus (Fig. 2.10 A). Their “bite” could be harder and they could graze more efficiently on encrusting organisms. In the Cretaceous, the camarodont lantern evolved in the Temnopleuroida, and by the end of that period, many groups of echinaceans with stirodont lanterns had become extinct and were mostly replaced by camarodont echinoids. In the following Tertiary, the most recent, regular group, the Echinoida, evolved, being specialized for life on rocky bottoms in shallow water with stronger wave activity. The third group of Acroechinoidea, the Irregularia, evolved in the early Jurassic from tiny opportunistic regulars like Eodiadema Duncan, 1889. They made the adaptive breakthrough to living and feeding on loose mobile sediment. In this new habitat, changes in lifestyle and

morphology progressed step by step: the first irregular echinoids were simply adapted for locomotion over unconsolidated sedimentary bottoms by having broader, flattened oral sides with shorter, but more numerous spines. Later, they may have lived semi-infaunally, shallowly digging, before they become adapted for burrowing. They ploughed unidirectionally(!) through the sediment, while waste material was channeled through a depressed anal groove toward the posterior end of the test. The bilateral symmetry, i.e. the antero-posterior polarity with two equal sides, allowed the evolution of shapes, structures, and specializations, which were new to echinoids. Early irregulars like the Pygasteroida and the Holectypoida could only live in coarse sediments, remaining more or less stationary. They had to return to the surface, perhaps at night, to feed using only their lantern. But very quickly, by the end of the Lower Jurassic, species had evolved that were able to collect the food with their suckered tube feet of the oral side (Fig. 2.12 A). On the upper side of the test, the podia in the ambulacra were modified into specialized respiratory tube feet, which extracted oxygen from the surrounding water through their thin body walls. The dense uniform spine canopy enabled cassiduloids and disasteroids to move into finer sediments, and soon, the two groups were adapted to different niches. The cassiduloids developed specialized spines and tube feet around the peristome to increase the quantity of sediment that could be ingested (Fig. 2.11). Teeth were no

2.4 Evolution and phylogeny 



A

 17

B

Fig. 2.11: (A) Cassiduloid Clypeus plotii Leske, 1778. Aboral side, length 102 mm; Middle Jurassic, England (coll. HM). With the five narrow ambulacra, the test still resembles in appearance that of a regular echinoid. But as the periproct has moved out of the apical system, lying immediately posterior in a deeply depressed groove, the echinoid is bilaterally symmetrical with a clearly defined anterior and posterior. (B) Cassiduloid Hardouinia mortonis Michelin, 1855. Oral side, length 51 mm; Upper Cretaceous, USA. The mouth is encircled by large podia, penetrating through pores, conspicuously arranged like leaves. The prominent tooth-like areas are set with spines. Both the spines and the tube feet are specialized to shovel large quantities of sediment into the peristome.

longer necessary; only in early ontogenetic stages are they still present. Thus, the cassiduloids were able to colonize sediments with a relatively low organic content. The disasteroids by contrast evolved tube feet ending in discs with numerous finger-like digits, which allowed them to collect selectively fine-grained, organic particles by mucous adhesion. The evolution of these penicillate podia was an important innovation, and the disasteroids subsequently gave rise to the Holasteroida and Spatangoida in Late Jurassic to Early Cretaceous, both of which inherited this kind of tube foot (Fig. 2.12 A, B). The spatangoids especially became much better adapted for burrowing, and they were able to live infaunally even within fine muddy sediments. They evolved fascioles, bands of ciliated tiny spines that create a current of fresh water over the respiratory podia and the whole surface. The tube feet of the anterior ambulacrum no longer served for respiration but became differentiated for funnel building, selection of food, or sensory reception. On the oral side, the posterior interambulacral plates enlarged and became set with strong spines for excavating. Burrowing in sediments thus led to the evolution of

new feeding and food transporting techniques in tandem with morphological changes. The spatangoids diversified during the Tertiary, often into niches previously held by holasteroids, and today, they are found in almost all grades of sediment, burrowing down to depths of 20 cm below the sea bottom. The holasteroids lack funnel-building tube feet. Generally, in contrast to the spatangoids, they have never been particularly successful burrowers (Fig. 2.12 B). After their severe decline at the Cretaceous-Tertiary boundary, they became restricted mainly to deep-sea environments, where they have evolved an efficient method of scooping up the surface detritus layer by scooping it directly along the oral groove into the vertical mouth – without using any specialized spines or tube feet. In the early Tertiary, the Clypeasteroida evolved from some form of cassiduloids. With their flat tests, equipped with very numerous short, differentiated spines, they are adapted to move through the detritus-rich uppermost layer of the sediment. Enormous numbers of tiny tube feet with suckered discs, arranged in broad areas all over the strongly enlarged ambulacra, collect fine organic material from among the sand grains. These particles are laid into food

18 

A

 2 Echinoid biology

B

Fig. 2.12: (A) Penicillate podium of extant spatangoid, Amphipneustes lorioli Koehler, 1901, length 3 mm; Weddell Sea, Antarctica. AWI. The finger-like processes at the distal end of the extensible tube foot are specialized for food grasping supported by internal, calcareous rods. The contracted shaft has a length of 2 mm; the digits at the disc are 1 mm long. (B) Holasterid Hemipneustes striatoradiatus (Leske, 1778). Aboral side, length 84 mm; Upper Cretaceous, Netherlands (coll. HvN). In each petal, slit-like pore pairs are developed, and the tube feet were elongated and leaf-shaped with a strongly enlarged surface for more efficient gaseous exchange. The anterior furrow was overarched by spines to protect and cover the mucous string with its food particles.

A

B



grooves to be transported in a mucous string toward the mouth to be crunched by the broadly winged, internal teeth (Fig. 2.13 A, B). Obviously, this innovation was very efficient, for within 15 to 20 million of years these sand dollars with their flat discs had expanded all over the world. Thus, the evolution of crucial new morphological features has led to the adoption of new modes of life or has

2.4 Evolution and phylogeny 

 19

allowed access to new habitats. After each adaptive breakthrough, a more or less rapid radiation and diversification in morphology follows, until the possibilities of the new niches are exhausted. Literature: Kier 1974, 1982; Phelan 1977; Smith 1984, 2004; David 1988; Hendler et al. 1995; Smith et al. 2005; Kroh & Smith 2010; Smith & Kroh 2011.

◂ Fig. 2.13: (A) Clypeasteroid Monostychia australis Laube, 1869; aboral side, test length 42 mm; Tertiary, Miocene, South Australia. The

ambulacra are broad, each marked by a food groove, which leads round the margin to the central mouth. (B) Clypeasteroid Monophoraster darwini (Desor, 1847). Oral side, test length 58 mm; Tertiary, Miocene, Argentina. The branched food grooves spread over the surface. The periproct is situated between the peristome and the small anal lunule).

3 Classification and systematics Sea urchins were long classified in the traditional ­hierarchical system used since Linné (1758). In the course of time, the order into classes, orders, families, and genera became finer and finer by addition of supertaxa, infrataxa, or subtaxa, etc. Increasingly more specimens were discovered and examined, and modern technology of sampling and microbiological investigation revealed more detailed characteristics including genetic, reproductive, and ecological aspects. By means of computer Class Echinoidea Leske, 1778 Subclass Cidaroidea Smith, 1984 Order Cidaroida Claus, 1880 Family Cidaridae Gray, 1825 Subfamily Cidarinae Mortensen, 1928 Genus Acanthocidaris Mortensen, 1903 Genus Calocidaris H. L. Clark, 1907 Genus Centrocidaris A. Agassiz, 1904 Genus Chondrocidaris A. Agassiz, 1863 Genus Cidaris Leske, 1778 Genus Compsocidaris Ikeda, 1939 Genus Eucidaris Pomel, 1883 Genus Hesperocidaris Mortensen, 1928 Genus Kionocidaris Mortensen, 1932 Genus Lissocidaris Mortensen, 1939 Genus Phyllacanthus Brandt, 1835 Genus Plococidaris Mortensen, 1909 Genus Prionocidaris A. Agassiz, 1863 Genus Stylocidaris Mortensen, 1909 Genus Tretocidaris Mortensen, 1903 Subfamily Ctenocidarinae Mortensen, 1928 Genus Aporocidaris A. Agassiz & H. L. Clark, 1907 Genus Ctenocidaris Mortensen, 1910 Genus Homalocidaris Mortensen, 1928 Genus Notocidaris Mortensen, 1909 Genus Rhynchocidaris Mortensen, 1909 Subfamily Goniocidarinae Mortensen, 1928 Genus Austrocidaris H. L. Clark, 1907 Genus Goniocidaris Desor, in Agassiz & Desor Genus Ogmocidaris Mortensen, 1921 Genus Psilocidaris Mortensen, 1927 Genus Rhopalocidaris Mortensen, 1927 Genus Schizocidaris Mortensen, 1903 Subfamily Stereocidarinae Lambert, 1900 Genus Phalacrocidaris Lambert, 1902 Genus Stereocidaris Pomel, 1883 Family Histocidaridae Lambert, 1900

programs, it is ­possible to handle enormous quantities of data creating cladistics trees (e.g. Kroh & Mooi 2010, Smith & Kroh 2015), and analyses of gene sequences or entire genomes supplement such analyses. Such analyses are not always congruent, and therefore, it was chosen here to use the classification from the World Echinoidea Database (version 3.0) (slightly simplified). It is part of WoRMS (the World Register of Marine Species) and incorporates many recent advances in echinoid systematic: Genus Histocidaris Mortensen, 1903 Family Psychocidaridae Ikeda, 1936 Genus Psychocidaris Ikeda, 1935 Subclass Euechinoidea Bronn, 1860 Order Echinothurioida Claus, 1880 Family Kamptosomatidae Mortensen, 1934 Genus Kamptosoma Mortensen, 1903 Family Phormosomatidae Mortensen, 1934 Genus Hemiphormosoma Mortensen, 1934 Genus Paraphormosoma Mortensen, 1934 Genus Phormosoma Thomson, 1872 Family Echinothuriidae Thomson, 1872 Genus Araeosoma Mortensen, 1903 Genus Asthenosoma Grube, 1868 Genus Calveriosoma Mortensen, 1934 Genus Hapalosoma Mortensen, 1903 Genus Hygrosoma Mortensen, 1903 Genus Sperosoma Koehler, 1897 Genus Tromikosoma Mortensen, 1903 Infraclass Acroechinoidea Smith, 1981 Order Aspidodiadematoida Kroh & Smith, 2010 Family Aspidodiadematidae Duncan, 1889 Genus Plesiodiadema Pomel, 1883 Genus Aspidodiadema A. Agassiz, 1878 Order Diadematoida Duncan, 1889 Family Diadematidae Gray, 1855 Genus Astropyga Gray, 1825 Genus Centrostephanus Peters, 1855 Genus Chaetodiadema Mortensen, 1903 Genus Diadema Gray, 1825 Genus Echinothrix Peters, 1853 Genus Eremopyga A. Agassiz & H. L. Clark, 1908 Genus Goniodidema Mortensen, 1939 Genus Lissodiadema Mortensen, 1903

22 

 3 Classification and systematics

Order Micropygoida Kroh & Smith, 2010 Family Micropygidae Mortensen, 1903 Genus Micropyga A. Agassiz, 1879 Order Pedinoida Mortensen, 1939 Family Pedinidae Pomel, 1883 Genus Caenopedina A. Agassiz, 1869 Carinacea Kroh & Smith, 2010 Superorder Calycina Gregory, 1900 Order Salenioida Delage & Hérouard, 1903 Family Saleniidae L. Agassiz, 1838 Genus Salenocidaris A. Agassiz, 1869 Genus Bathysalenia Pomel, 1883 Superorder Echinacea Claus, 1876 Order Stomopneustoida Kroh & Smith, 2010 Family Glyptocidaridae Jensen, 1982 Genus Glyptocidaris A. Agassiz, 1864 Family Stomopneustidae Pomel, 1883 Genus Stomopneustes L. Agassiz, 1841 Order Arbacioida Gregory, 1900 Family Arbaciidae Gray, 1855 Genus Arbacia Gray, 1835 Genus Arbaciella Mortensen, 1910 Genus Coelopleurus L. Agassiz, 1840 Genus Dialithocidaris A. Agassiz, 1898 Genus Habrocidaris A. Agassiz & H. L. Clark, 1907 Genus Podocidaris A. Agassiz, 1869 Genus Pygmaeocidaris Döderlein, 1905 Genus Tetrapygus L. Agassiz, 1841 Order Camarodonta Jackson, 1912 Family Parasaleniidae Mortensen, 1903 Genus Parasalenia A. Agassiz, 1863 Infraorder Temnopleuridea Kroh & Smith, 2010 Family Temnopleuridae A. Agassiz, 1872 Genus Amblypneustes L. Agassiz, 1841 Genus Erbechinus Jeannet, 1935 Genus Holopneustes L. Agassiz, 1841 Genus Mespilia Desor in Agassiz & 1846 Genus Microcyphus L. Agassiz, 1846 Genus Opechinus Desor, 1856 Genus Paratrema Koehler, 1927 Genus Printechinus Koehler, 1927 Genus Pseudechinus Mortensen, 1903 Genus Salmaciella Mortensen, 1942

Genus Salmacis L. Agassiz, 1841 Genus Temnopleurus L. Agassiz, 1841 Genus Temnotrema A. Agassiz, 1863 Family Trigonocidaridae Mortensen, 1903 Genus Asterechinus Mortensen, 1942 Genus Desmechinus H. L. Clark, 1923 Genus Genocidaris A. Agassiz, 1869 Genus Hypsiechinus Mortensen, 1903 Genus Prionechinus A. Agassiz, 1879 Genus Trigonocidaris A. Agassiz, 1869 Infraorder Echinidea Kroh & Smith, 2010 Family Echinidae Gray, 1825 Genus Dermechinus A. Agassiz, 1879 Genus Echinus Linné, 1758 Genus Gracilechinus Fell & Pawson, 1966 Genus Polyechinus Döderlein, 1905 Genus Sterechinus Koehler, 1901 Genus Stirechinus H. L. Clark, 1912 Family Echinometridae Gray, 1855 Genus Caenocentrotus H. L. Clark, 1912 Genus Colobocentrotus Brandt, 1835 Genus Echinometra Gray, 1825 Genus Echinostrephus A. Agassiz, 1863 Genus Evechinus Verrill, 1871 Genus Heliocidaris L. Agassiz & Desor, 1846 Genus Heterocentrotus Brandt, 1835 Genus Selenechinus de Meijere, 1903 Genus Zenocentrotus H. L. Clark, 1931 Family Parechinidae Mortensen, 1903 Genus Loxechinus Desor, 1856 Genus Paracentrotus Mortensen, 1903 Genus Parechinus Mortensen, 1903 Genus Psammechinus L. Agassiz & Desor, 1846 Family Strongylocentrotidae Gregory, 1900 Genus Hemicentrotus Mortensen, 1942 Genus Mesocentrotus Tatarenko & Poltaraus, 1993 Genus Pseudocentrotus Mortensen, 1903 Genus Strongylocentrotus Brandt, 1835 Family Toxopneustidae Troschel, 1872 Genus Cyrtechinus Mortensen, 1942 Genus Goniopneustes Duncan, 1889 Genus Gymnechinus Mortensen, 1903 Genus Lytechinus A. Agassiz, 1863 Genus Nudechinus H. L. Clark, 1912 Genus Pseudoboletia Troschel, 1869 Genus Sphaerechinus Desor, 1846 Genus Toxopneustes L. Agassiz, 1841 Genus Tripneustes L. Agassiz, 1841

4 Taxonomy: systematic descriptions 4.1 Subclass Cidaroidea Smith, 1984 4.1.1 Order: Cidaroida Claus, 1880 Introduction: The Cidaroids, the oldest group of extant echinoidea, live in sheltered environments in reefs, on hard grounds such as rocks or corals, or on firm sand. Most of them inhabit waters deeper than 50  m. By daylight, they hide beneath coral blocks or in crevices, emerging at night walking on their oral spines and grazing on encrusting organisms like algae and microscopic animals. The large primary spines themselves provide a habitat of many other animals or algae, mostly bryozoans, calcareous algae, small molluscs, and even sessile sea cucumbers. The spines are not covered by living skin (epithelium), as in all other sea urchins. Only near the base, within the reach of the pedicellariae, the setting of foreign organisms is not to be found. Some species have evolved a fur-like hair canopy over the lower shaft, which serves for anti-fouling. Other species have developed broad spines, which seem to be an “invitation” for encrusting organisms to settle, serving as camouflage against predators. The cidaroids with their pentameral symmetry show rather few distinct features, which have remained in the main stable for hundreds of million years. Differences are mostly only evident in the shape of the primary spines and the pedicellariae. Denuded tests are often difficult to distinguish. Remark: Many of the original descriptions by L. and A. Agassiz, H.L. Clark, Döderlein, Mortensen, and others were based on a single or at most on very few specimens, and slightly distinguishing characteristics were often pointed out as basis for new species or varieties. The order is characterized by the following features (Fig. 4.1, 4.2): Test: Strong, lacking buccal notches. Ambulacra: Very narrow, plates simple, pore pairs in a single series, small marginal tubercles on interporiferous zone (secondaries) carrying small spines. Interambulacra: One large primary tubercle per plate carrying a single large spine. Peristome: Perforated ambulacral plates continuing to mouth opening; apophyses in interambulacral position; teeth unkeeled. Superfamily Cidaridea Gray, 1825 Primary tubercles perforated; globiferous pedicellariae present.

This family is subdivided into four subfamilies, roughly characterized by the following features: Cidarinae: Primary tubercles non-crenulate or with just traces of crenulation on aboral tubercles; no pits or grooves; scrobicular tubercles distinctly larger than the extrascrobicular ones. Ctenocidarinae: Scrobicular tubercles not much larger than extrascrobicular ones, globiferous pedicellariae without end tooth; the species live almost exclusively in Antarctic and subantarctic waters. Goniocidarinae: Pits and grooves in horizontal sutures, globiferous pedicellariae with end tooth. Stereocidarinae: Non-functional primary tubercles on the adapical interambulacral plates. Superfamily Histocidaroidea Consisting of two families: Histocidaridae Lambert, 1900. Primary tubercles perforated and strongly crenulated; scrobicular ring not complete, no cortical hair on primary spines; globiferous pedicellariae absent. Psychocidaridae Ikeda, 1936. Coarse primary spines with club-shaped shaft; no interradial plates on peristome; tubercles generally without perforation. Only a single extant genus with one species.

4.1.1.1 Family Cidaridae Gray, 1825 Subfamily Cidarinae Mortensen, 1928 The subfamily contains 15 genera: Acanthocidaris Mortensen, 1903. Three species, IndoPacific. Calocidaris H. L. Clark, 1907. Monospecific, Caribbean. Centrocidaris A. Agassiz, 1904. Monospecific; Pacific Central America. Chondrocidaris A. Agassiz, 1863. Two species, Indo-West and Central Pacific. Cidaris Linné, 1758. Five species, restricted to the Atlantic. Compsocidaris Ikeda, 1939. Monospecific, West Pacific. Eucidaris Pomel, 1883. Four species, in tropical waters. Hesperocidaris Mortensen, 1928. Five species, East Pacific. Kionocidaris Mortensen, 1932. Monospecific, South Africa. Lissocidaris Mortensen, 1939. Two species, Indo-Pacific. Phyllacanthus Brandt, 1835. Seven species, Indo-Pacific. Plococidaris Mortensen, 1909. Monospecific, Indo-Pacific.

24 

A

 4.1 Subclass Cidaroidea Smith, 1984

genital plate with pore

B

madreporite with pore

ambulacrum A

ambulacral peristomial plates

A III

A III

IA 3

IA 3

IA 2

IA 2

teeth

A IV

A IV

A II

A II

IA 1

IA 4

IA 4

IA 1 mouth AV

AI

AI

AV IA 5

IA 5

C

interambulacral peristomeal plates

occular plate

periproctal plates

D

madreporite genital plate

ocular plate, insert

anus

periproctal plates

F median zone naked / tuberculated

mouth with teeth

apophysis

test

peristomial membrane teeth

ambulacral peristomial plates

G scrobicular tubercles

E

interambulacral peristomial plates

ocular plate, exsert

interambluacrum IA

pore zone

interporiferous zone

muscles

H

pore zone pore-pair

areole shaft median suture

non-crenulate / crenulate perforate primary tubercle

horizontale sature

small tubercles marginal tubercle

small tubercle median suture

milled ring

neck collar base

4.1.1 Order: Cidaroida Claus, 1880 



marginal spines

primary spines

scrobicular spines small spines Fig. 4.2: (A) Diagram of cidaroid primary spine. At the milled ring, strong muscles are attached that lead to the areole. (B) Teeth of cidaroid. The jaw apparatus, also called “Aristotle’s lantern”, is massive; the strong muscles moving the teeth are supported by paired processes (apophyses) at the inner side of the test in interambulacral position (modified after Märkel 1979). (C) Cidaroid spines: the cidaroid echinoids are provided with three kinds of spines associated with tubercles. One large primary spine is carried by a large primary tubercle on each interambulacral plate. Secondary spines are distinctly smaller and are carried by smaller tubercles. They comprise (i) scrobicular spines encircling the base of the primary spine on the interambulacra like a palisade; the associated tubercles surround the areole; (ii) marginal spines in the ambulacra cover the pore zones – the associated tubercles form a regular series; (iii) Small spines are distributed on the remaining areas of the test to differing densities.

Prionocidaris A Agassiz, 1863. Nine species, Indo-Pacific. Stylocidaris Mortensen, 1909. Numerous species in tropical and temperate waters. Tretocidaris Mortensen, 1903. Two species, Atlantic.

◂ Fig. 4.1: Cidarids:(A) Aboral

 25

Genus Acanthocidaris Mortensen, 1903 This genus is characterized by having very conspicuous primary spines with a broad, long, and more or less flattened collar, which is ornamented by longitudinally arranged darker or lighter spots. The primary tubercles are distinctly crenulated. Acanthocidaris curvatispinis Bell, 1892. Indo-West Pacific, Mauritius to Japan and Australia. Acanthocidaris hastigera A. Agassiz & H. L. Clark, 1907. Hawaii. Acanthocidaris maculicollis de Meijere, 1904. Type locality Indonesia, Sunda Islands. Remark: Rowe & Hoggett (1986) compared many specimens from Australian waters and Hawaii, and they recognized the large range of variation in spine ornamentation and color. They suppose all three species may be synonymous. Acanthocidaris curvatispinis Bell, 1892 (Fig. 4.3 A–C) Test: High, flattened above and below; test diameter may reach 61 mm. Apical system: About half the test diameter, ocular plates usually insert, covered regularly by small tubercles, which sometimes show a radial prolongation. Ambulacra: Sinuous, pore pairs horizontal; marginal tubercles small, median zone with a few scattered tubercles, slightly sunken. Interambulacra: 9 plates in a column; primary tubercles perforate and distinctly crenulated, strongest adapically; areoles separated except near the peristome. Primary spines: Long, tapering, and flattened, with blunt tip; collar very broad and long, ornamented with longitudinally arranged spots or nodes; shaft with fine, more or less distinct longitudinal ridges; oral primaries curved, serrated along the sides; collar often longer than the shaft.

side with apical system. (B) Oral side with peristome: The five ambulacra are narrow and more or less sinuous. They consist of a double row of numerous small, simple plates, each perforated by one pore-pair. The plate series continue over the peristomial membrane to the mouth. They are labelled A I to A V. The five broad double series of the interambulacra are built of a few large plates each set with one large tubercle. They are labelled from IA 1 to IA 5. As the madreporite is always situated in IA 2, the other plates can be ­determined. (C) Aboral side with apical system: The genital and ocular plates are arranged in a ring, encircling the periproct. The ocular plates may reach the periproctal edge (insert) or not (exsert). The periproct is covered with plates, the opening of the anus more or less in the centre. (D) Oral side with peristome: The peristome is closed by a membrane, which is covered by five series of perforated ambulacral plates, and interambulacral plates, which develop to different degrees. In the centre the mouth opens with five teeth (called “Aristotle’s lantern”). (E) Teeth of cidaroid. The jaw apparatus is massive, the strong muscles moving the teeth are supported by paired processes (apophyses) at the inner side of the test in interambulacral position. (Modified after Märkel 1979.) (F) One interambulacral plate: The primary tubercle is surrounded by a large areole, bordered by the scrobicular tubercles. The platform of the tubercle may be smooth or crenulated. The space at the median zone of the plate may be naked or set with small tubercles. The smooth surface of the areoles is where the muscles of the spines attach. (G) Ambulacral plate: Two series of pore-pairs make up the pore zones at the outer parts of the plates. The interporiferous zone expands along the median suture and is more or less set with tubercles. (H) Diagram of cidaroid primary spine. At the milled ring strong muscles are attached that lead to the areole (see in F).

26 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

Fig. 4.3: (A–C) Acanthocidaris curvatispinis. Aboral side with long primary spines, diameter of test 14 mm; Port Louis, Mauritius. ZMUC. (B) Oral side. (C) Primary spines of the oral side: (left: upper side; right: underside). Scale: 5 mm. (A) From A. Agassiz & H.L. Clark (1907).

4.1.1 Order: Cidaroida Claus, 1880 



A

 27

B

C

D

Fig. 4.4: (A, B) Acanthocidaris hastigera. (A) Side view, diameter of test 45 mm; Hawaii. ZMUC. The primary tubercles are strongly crenulated. (B) Oral side. (C, D) Acanthocidaris maculicollis. (C) Aboral side, diameter 21 mm; Cebu, Philippines. ZMUC. (D) Aboral side with spines, test diameter 20 mm; Philippines. ZMUC.

Secondary spines: Flattened, not appressed, but rather erect. Color: The patterns on the collar and on the shaft are formed mainly of darker brown or reddish spots on a white, creamy, or olive green ground. Additionally, there are darker lines in brown or olive green along the midlines of ambulacra and/or interambulacra or spots between the aboral primary tubercles and on the genital plates. ­Secondary spines yellowish.

Distribution: Acanthocidaris curvatispinis is wide-spread in the Indo-West Pacific: from Mauritius through the Malayan Archipelago and the Philippines to Japan, then to Australia (Western Australia, along the tropical northern to the southeastern coast of New South Wales). Bathymetric range 40 to 355 m. Acanthocidaris hastigera A. Agassiz & H. L. Clark, 1907 (Fig. 4.4 A, B) Very similar to Acanthocidaris curvatispinis.

28 

 4.1 Subclass Cidaroidea Smith, 1984

Test: Diameter may reach 52  mm. Acanthocidaris ­hastigera differs in the brown color of its secondary spines, the collar appears to be a little longer than in A. curvatispinis. Distribution: Probably endemic to the Hawaiian Islands, 57 to 355 m. Acanthocidaris maculicollis de Meijere, 1904 (Fig. 4.4 C, D) This species resembles very much A. curvatispinis. Often, the collar of the primary spines is set with red spots and the shaft may be banded. Distribution: Type locality: Indonesia, Sunda Islands, at depths of 69 to 94 m. Genus Calocidaris H. L. Clark, 1907 This monospecific genus is characterized by entirely smooth and shiny primary spines.

A

B

C

D

Calocidaris micans Mortensen, 1903 (Fig. 4.5 A, B) Test: Relatively high, up to 75 % of test diameter, not flattened above or below. Apical system: Madreporite not larger than other genital plates, plates densely tuberculated; ocular plates just exsert or just insert. Ambulacra: Interporiferous zone at ambitus with four series of almost equal-sized tubercles, inner tubercles adorally and adapically smaller than marginal ones and more irregular; poriferous zone narrow. Interambulacra: Areoles large and round, scrobicular tubercles well differentiated, reaching the upper and lower edge of plates; median zone depressed toward midline, extrascrobicular tubercles in horizontal series; aboral primary tubercles faintly crenulated at upper side. Primary spines: Long and slender, up to 3 times the diameter, but usually 1.5 times, tapering gently to the tip,

Fig. 4.5: (A, B) Calocidaris micans. (A) Aboral side, diameter 49 mm, longest spine 90 mm; Havana, Cuba. ZMUC. (B) Side view: the scrobicular spines are much larger than the other secondaries. (C, D) Centrocidaris doederleini. (C) Oral side, diameter of test 14 mm; Galapagos Islands. ZMUC. (D) Aboral side with spines, diameter of test 12 mm; Galapagos Islands. ZMUC.



totally smooth and shiny, lacking hairs or granules; above the ambitus, set with about 16 glassy zones slightly elevated longitudinally, visible only to the aided eye; below the ambitus, they form faint, glassy ridges; oral primaries flattened with ridges and thin edges. Secondary spines: Scrobiculars long and appressed; other secondaries much smaller and pointed at the tip. Color: Test and secondary spines light brown to beige; primary spines white with faintly red brown tip, collar red brown or pink, neck and shaft light olive; cleaned test white with very slight olive tint. Distribution: West Indies and Gulf of Mexico at a depth of 200 to 330 m. Biology: Recent deep-sea submersible expeditions in the Bahamas revealed interactions between Calocidaris micans and the stalked crinoid Endoxocrinus parrae (Gervais in Guérin 1835). The in situ observations suggest that these sea urchins, often occurring in “meadows” of sea lilies, prey on live crinoids, which respond by shedding the distal stalk portions and rapidly crawling away (Baumiller et al. 2008). Literature: Mortensen 1903, 1910; Phelan 1970; Coppard & van Noordenburg 2007. Genus Centrocidaris A. Agassiz, 1904 This monospecific genus is characterized by its high and rather naked genital plates. Centrocidaris doederleini A. Agassiz, 1898 (Fig. 4.5 C, D) Test: Small, not exceeding 30  mm; low, flattened above and below. Apical system: Ocular plates exsert, genital plates remarkably high and narrow; consequently, the periproct is small; all plates rather naked, some small tubercles along the outer edges, a single usually in the middle of the genital plates. Ambulacra: Almost straight, relatively broad, in width almost half of interambulacra; interporiferous zone twice the width of pore zone; marginal tubercles regular and contiguous, usually a single inner tubercle per plate, narrow naked midline. Interambulacra: Areoles large and shallow, almost completely filled by the boss; adorally coalescing; scrobicular tubercles slightly larger than marginal tubercles; median space with a single series of extrascrobicular tubercles and a distinct naked midline. Peristome: Smaller than apical system. Primary spines: In length, about 1–1.5 times the test diameter; slender, cylindrical; aborally with indication of about 10 low ridges, cortical hair well developed, forming a dense meshwork covered by a glabrous crust appearing totally smooth; below the ambitus, set with more or less distinct fine teeth, oral primaries serrated.

4.1.1 Order: Cidaroida Claus, 1880 

 29

Secondary spines: Long, very slender, club-shaped, not appressed. Globiferous pedicellariae: Stem of globiferous pedicellariae with limb. Color: Primary spines white, collar yellowish; secondaries greenish with a faint darker midline; naked median space in ambulacra and interambulacra in life dark purple to red violet; apical system white with dark purple to brown sutures; denuded test white with greenish-olive tint and brown to violet-red interporiferous zones in ambulacra. Distribution: West coast of central America, Cocos and Galapagos Islands. Depth 91 to 550 m. Literature: Mortensen 1928; Lessios 2005. Genus Chondrocidaris A. Agassiz, 1863 This genus, consisting of two species, is characterized by strongly sculptured primary spines. Chondrocidaris brevispina H. L. Clark, 1925 (Fig. 4.6 A–C) Test: Flattened above, horizontal diameter of test reaches 55 mm. Apical disc: Ocular plates exsert, whole apical system covered with very small, glassy tubercles, with a circle of larger ones around the anus. Ambulacra: Rather sinuate; marginal tubercles regular, median space covered with small spines, the tubercles being glassy; pores equal-sized and conjugate. Interambulacra: Distinctly separated areoles, median space closely covered with very small tubercles of uniform size, leaving no naked or sunken median or horizontal lines; scrobicular tubercles well differentiated. Peristome: Distinctly larger than apical system, rather conically protruding. Primary spines: In length, less than diameter of test in adult, relatively longer in young specimens; long vaseshaped collar, which may reach a length of 15 mm in large specimens, sharply separated from the shaft carrying coarse thorns, developing into longitudinal ridges toward the tapering or flaring distal end; in well-preserved specimens, the shaft is set with a thick coat of fur-like hair. Secondary spines: Scrobicular spines ca. 3  mm long, with distinct longitudinal ridges, truncated at the distal end; marginal spines rounded at the point; all of them strongly appressed. Color: Test and spines are rather variable, mostly olive green, more rarely yellow, the collar and shaft of spines more or less coral-red, younger specimens are generally lighter. Distribution: This species lives probably throughout the whole Malayan Archipelago and eastward to the South Pacific Islands such as Samoa at depths of 10 to 15 m. Literature: Guille et al. 1986.

30 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

D

E



Chondrocidaris gigantea A. Agassiz, 1863 (Fig. 4.6 D, E) In the test, the structure very much resembles C. brevispina. Test: Diameter may reach 100 mm. Ambulacra: Almost straight. Primary spines: At ambitus scarcely exceeding test diameter, but sometimes reaching 1.5 of horizontal diameter, the upper ones considerably shorter; cylindrical, set with very coarse, irregularly arranged thorns, which develop toward the distal end of the spines gradually into high ridges, tip may form a rather large, flaring, irregular crown; shaft sharply limited to the smooth collar; oral primaries simple, ending distally with tapering ridges. Secondary spines: Scrobiculars ca. 10  mm long, quite flattened, more or less straight cut; ambulacral spines ca. 5 mm long, also flattened; small spines very small, scarcely 1 mm; cone-shaped. Color: The primary spines are dark chocolate or more reddish, the scrobiculars yellow red, the other secondaries yellow; the denuded test is slightly green, sometimes with brown midlines in the interambulacra. Distribution: Known from the Hawaiian islands from depths of about 10–380 m, also reported from Guam, Samoa, Rarotonga, Indonesia, and from Mauritius in the Indian Ocean. Genus Cidaris Leske, 1778 Test: Rather thick, more or less flattened above and below. Apical disc: About half the test diameter; all genital plates of about same size. Ambulacra: Slightly sinuous, pore zones narrow and sunken, interporiferous zone with contiguous series of marginal tubercles and inner series of smaller tubercles. Interambulacra: With 6–9 plates per column, areoles round and distinctly sunken, separated, confluent only adorally; scrobicular tubercles well differentiated; extrascrobicular space narrow, densely covered by smaller secondary tubercles. Peristome: Smaller than apical system. Primary spines: Usually long, cylindrical, shaft sometimes slightly thickened; with more or less finely serrated ridges; collar and neck short; secondary spines appressed. Pedicellariae: Large globiferous with a single, large end tooth and a large blade opening. Distribution: This genus is restricted to the Atlantic Ocean including the Mediterranean and Caribbean Sea. It consists of five species: Cidaris abyssicola A. Agassiz, 1869. East coast of the USA, West Indies.

4.1.1 Order: Cidaroida Claus, 1880 

 31

Cidaris blakei A. Agassiz, 1878. West Indies from Cuba to Barbados. Cidaris cidaris Linné, 1758. North Atlantic and Mediterranean. Cidaris nuda Mortensen, 1903. Cape Verde Islands and Gulf of Guinea. Cidaris rugosa H. L. Clark, 1907. Off Georgia, USA, and West Indies. Literature: Phelan 1970; Mortensen 1910, 1927, 1928. Cidaris abyssicola A. Agassiz, 1869 (Fig. 4.7 A, B) Test: Usually rather low. Apical system: Densely tuberculated, inner edge of genital plates with naked line. Interambulacra: Areoles not very large, uppermost primary tubercles often rudimentary. Primary spines: Fairly smooth, but usually not shiny; spines below the ambitus with very small spinules (visible with a magnifying glass); length about 1 to 1.5 times the test diameter, shaft cylindrical or slightly thickened at the base. Oral primary spines: Distinctly serrated edges. Color: Test and primary spines generally white, sometimes with pink or olive tint, collar of primary spines and the secondary spines may be light brown. Distribution: East coast of the USA from Cape Cod to Florida, West Indies. Bathymetric range 200 to 400 m. Cidaris blakei A. Agassiz, 1878 (Fig. 4.7 C–E) Test: Flattened above. Apical system: Ocular pores encircled by a rim. Ambulacra: Pore pairs slightly oblique; marginal tubercles regular, inner ones densely set and variably irregular. Interambulacra: Areoles large, especially above the ambitus; extrascrobicular tubercles very small, almost granular. Primary spines: Uppermost ones often almost fan-shaped, decreasing in width toward the ambitus; below the ambitus slender, lacking a widened tip; but variation is large, there may also be specimens without any widening of spines; all of them are densely set with distinct, not thorny spinules, except the oral ones, which are laterally serrated. Secondary spines: Scrobiculars large, broad and bluntly tipped; marginal spines much smaller, slender, slightly flattened and almost pointed; extrascrobicular secondaries very small. Color: Living specimens may have been a brilliant vermillion, according to A. Agassiz (1883), which fades out with time. Dried specimens are brown; the spines white.

◂ Fig. 4.6: (A–C) Chondrocidaris brevispina: aboral side of young specimen; diameter of test 19 mm; Marquesas Islands, Nuka Hiva, found under boulder at a depth of 15 to 20 m. (B) Oral side. (C) Primary spine of a large specimen: typical vase-shaped collar, scrobicular spines tightly appressed to the base. Sketch after a photo in Guille et al. (1986). (D, E) Chondrocidaris gigantea. (D) Aboral side with spines, diameter of test 70 mm; Lahaina, Hawaii, USA (coll. C. Neumann). (E) Oral side.

32 

 4.1 Subclass Cidaroidea Smith, 1984

A

C

B

D

E

Fig. 4.7: (A, B) Cidaris abyssicola. Aboral side with spines, diameter of test 35 mm; Gulf Stream. ZMUC ECH 563. (B) Aboral side of test, diameter 38 mm; Florida Straits, USA. ZMUC ECH 562. The plates are well tuberculated, sometimes there is a more or less broad naked band along the inner edge of the genital plates. (C–E) Cidaris blakei. (C) Aboral side with spines, diameter of test 33 mm; Cuba. ZMUC. The adapical primary spines are strongly widened and densely set with thorns, the ambital spines are slender and also set with thorns. All spines are settled by encrusting organisms. (D) Loose spine; length 56 mm. (E) Aboral side, partly with spines, diameter of test 34 mm; Barbados, Lesser Antilles. ZMUC. The primary spines are barely widened.

Distribution: West Indies from Cuba to Barbados at depths of 315 to 420 m. Cidaris cidaris Linné, 1758 (Fig. 4.8) Test: Of variable shape: high and flattened above and below, spherical or rather flat overall; maximum diameter 70 mm.

Apical system: Flat, all apical plates densely covered with small tubercles of uniform size, but with more or less conspicuous naked edges. Ambulacra: Interporiferous zone about twice the width of 1 pore zone; marginal tubercles regular, in larger specimens more or less regular double series of smaller ­tubercles in the median space, sometimes leaving a rather

4.1.1 Order: Cidaroida Claus, 1880 



A

B

C

D

 33

Fig. 4.8: Cidaris cidaris. (A) Aboral side with spines, test diameter 36 mm, height 26 mm, longest spine 67 mm; off Toulon, France. The length of the primary spines is larger than the diameter of test. (B) Aboral side of test, diameter 45 mm; Toulon, France. (C) Oral side of test. (D) Close-up of ambulacra and interambulacra.

naked median line; pores equal-sized, each pair separated from the next by a narrow wall, pore zones often sunken. Interambulacra: Areoles deepened, well separated, scrobicular tubercles not very conspicuous; outside the ring the plates densely covered with smaller tubercles decreasing gradually in size toward the distinctly marked median line. Primary spines: Long, slender, cylindrical, tapering gently to the blunt end, shaft with small granules in 12–16 rather sharp ridges; oral primaries short and ­flattened.

Secondary spines: Scrobiculars 5–6 mm long, flattened, tapering to the round top; marginal spines half the length, slender and pointed; small ones of same shape. Globiferous pedicellariae: With short stem and prominent end tooth. Color: In life, the test is grayish, the primary spines yellowish-gray with greenish points and bases; secondary spines green­ish as well. The bare test is uniformly cream-yellowish. Distribution: This species is found in the northeastern Atlantic from south of Iceland and Norway to the Azores,

34 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

D

Fig. 4.9: (A, B) Cidaris nuda. (A) Aboral side with spines, test diameter 35 mm; Cape Verde Island. ZMUC. (B) Close-up of aboral side, diameter of test 28 mm; Cape Verde Islands. ZMUC. It is not the number of secondary spines that gives the echinoid a naked appearance but the small size of the secondary spines. (C, D) Cidaris rugosa. (C) Aboral side partly with spines, diameter of test 32 mm; Martinique. ZMUC. The primary spines are set with coarsely serrated ridges. The serrations are not sharp, but rather blunt. (D) Side view.

Madeira, the Canaries, and Cape Verde Islands, along the east coast of the USA southward to Florida at depths of 50–2,000 m. It occurs also in the Mediterranean from the East Basin to Spain. Remarks: The distribution areas of Cidaris cidaris and Stylocidaris affinis (see page 59) are widely overlapping. Both species are very similar in test sculpture, but they differ in color: C. cidaris is usually beige to light brown, whereas S. affinis shows a darker ring on the apical system, a red brown stripe on the scrobicular spines and often also dark lines along the midlines of ambulacra and ­interambulacra. Cidaris nuda Mortensen, 1903 (Fig. 4.9 A, B) Test: Rather low, flattened above; diameter may reach 35 mm.

Apical system: Secondary tubercles covering the plates very short. Ambulacra: Barely a quarter the width of interambulacra; marginal tubercles regular, inner space narrow, small tubercles of either side form almost a vertical row. Interambulacra: Areoles rather large, leaving a narrow space outside the prominent scrobicular tubercles, ­extrascrobicular tubercles sparse. Primary spines: Slender, hardly tapering toward the tip, covered with rather coarse longitudinal ridges. Secondary spines: Scrobiculars narrow and pointed; marginal spines about half the length of scrobiculars, inner spines very short, about 0.5 mm, as also the apical spines.



Color: The test is a bright white, secondary spines red brown or purple, primary spines lighter red brown to purple or pink. Distribution: This species is known from the Cape Verde Islands and the Gulf of Guinea. It is also found on seamounts and knolls in the tropical East Atlantic. Bathymetric range 70 to 450 m. Cidaris rugosa H. L. Clark, 1907 (Fig. 4.9 C, D) Test: Mortensen (1928) reported a maximum diameter of 61 mm. Apical system: Covered with relatively coarse tubercles. Ambulacra: With a regular row of marginal tubercles, two series of small inner tubercles, sometimes irregularly crowded. Interambulacra: Areoles large, scrobicular tubercles prominent, extrascrobicular tubercles relatively coarse, decreasing in size toward the sutures. Primary spines: 1 to 1.5 times the diameter, markedly swollen just above the collar, tapering toward the tip; covered by distinct spinules, which are not sharply thorny; there may occur also non-thickened spines or some with slightly expanded, flattened tip; oral primaries are usually not serrated or only slightly. Secondary spines: All rather broad, flattened, and with blunt end, scrobicular spines may sometimes be distally truncated. Color: According to H. L. Clark (1907) the test of living ­specimens is more or less rose red to brick red. Distribution: Known from Cape Cod along the east coast of the USA through the Greater and Lesser Antilles as far as Barbados. Bathymetric range 130 to 540 m. Genus Compsocidaris Ikeda, 1939 The monospecific genus is characterized by its primary spines, being smooth and shiny basally becoming distinctly ridged toward the tip. Compsocidaris pyrsacantha Ikeda, 1939 (Fig. 4.10) Test: Large form, rather thick. Apical system: About half the width of diameter of test, usually monocyclic, ocular plates being narrowly insert; genital plates of similar size; all plates uniformly tuberculated. Ambulacra: Faintly sinuous, pore zones slightly sunken, interporiferous zone with two series of continuous marginal tubercles and two inner series of much smaller tubercles, leaving a naked midzone. Interambulacra: 6–8 plates per column, areoles circular and depressed, separated; adapical tubercles sometimes subcrenulate; scrobicular tubercles well differentiated, extrascrobicular space narrow with a few tubercles, more or less naked, sometimes with lines crossing the midline.

4.1.1 Order: Cidaroida Claus, 1880 

 35

Peristome: Smaller than apical system; ambulacral plates uniserial, interambulacral plates reaching the mouth. Primary spines: Slender and almost cylindrical, in length hardly reaching diameter of test; neck and collar short; shaft basally almost smooth, distally becoming ridged; all secondary spines slender and strongly appressed. Color: The test is light brown, the secondary spines are also light brown gradually becoming more or less red toward the tip. The primary spines may be also light brown or very conspicuously bright red even on the underside. The denuded test is creamy beige, but may be also a fine rose with red primary tubercles. There is a darker band in the genital plates. Distribution: The species is widely spread in the West Pacific from the Bonin Islands, Japan, to the Tasman Sea, Australia. Genus Eucidaris Pomel, 1883 The genus is characterized by its stout, rather short primary spines, which are ornamented with longitudinal beaded ribs; distally, they may end in a more or less flaring crown. Test: Moderately thick. Apical system: Mostly monocyclic, generally slightly smaller than peristome; madreporite larger than other genital plates. Ambulacra: Almost straight; pore pairs horizontal, separated by a ridge, which is as wide as a single pore; marginal tubercles in a regular series, contiguous. Interambulacra: Areoles hardly depressed, scrobicular tubercles clearly differentiated, not confluent; extrascrobicular tubercles heterogeneous. Primary spines: Short, stout, and usually cylindrical with blunt ends, sometimes flaring like a crown with a central knob, sometimes club-shaped; neck and collar short, shaft covered with more or less prominent beaded ribs. Secondary spines: Scrobiculars short, parallel-sided, and appressed; other secondaries of same form, but smaller. Five species are included in this genus, which have adjacent, but not overlapping geographical distributions: Eucidaris australiae Mortensen, 1950. Western Australia. Eucidaris galapagensis Döderlein, 1887. East Pacific, restricted to the Islands off the west American coast. Eucidaris metularia Lamarck, 1816. Widely distributed from East Africa to the central Pacific. Eucidaris thouarsii A. Agassiz & Desor, 1846. East Pacific at the central west American mainland. Eucidaris tribuloides Desmoulins, 1835. Tropical west Atlantic coast, the Caribbean, and West Africa and South

36 

 4.1 Subclass Cidaroidea Smith, 1984

A

C

B

D

Fig. 4.10: Compsocidaris pyrsacantha. (A) Aboral side with spines, diameter of test 70 mm; Norfolk Ridge, Tasman Sea, Australia. The primary spines hardly reach the diameter of test in length. (B) Oral side with spines. (C) Aboral side of test, diameter 63 mm; Norfolk Ridge, Tasman Sea. There is a faint dark band crossing in a bow the genital plates of this uniformly beige-colored specimen. (D) Side view of test, diameter of test 64 mm; Balut Island, Philippines.

Atlantic islands (including the variety Eucidaris tribuloides var. clavata Mortensen, 1928 Fig. 4.12 E). Literature: Mortensen 1928; Phelan 1970; Serafy 1979, Hendler et al. 1995; Lessios et al. 1999. Eucidaris australiae Mortensen, 1950 (Fig. 4.11 A) Mortensen described shortly only a single specimen with a test diameter of 37 mm, height 21 mm. Main ­characteristics

like genus; apical plates regularly set with tubercles of uniform size. Mortensen reported on curious tridentate pedicellariae their blade being completely filled with a dense meshwork (Mortensen 1950, p. 293). Color: On the whole, a uniform dusty greenish, with the secondary spines slightly darker to their end. The denuded test is white, only the apical system shows a faint greenish tint.

4.1.1 Order: Cidaroida Claus, 1880 



A

B

C

D

 37

Fig. 4.11: (A) Eucidaris galapagensis. Aboral side with spines, test diameter about 27 mm; Galapagos Islands. ZS Munich (photo by B. Ruthensteiner). (B–D) Eucidaris metularia. Aboral side of test, diameter of test 22 mm; Negros, Philippines. (C) Aboral side with spines, diameter of test 17 mm; Ile de la Réunion, Indian Ocean. The borderlines of the apical plates are distinct. (D) Oral side.

Distribution: Mortensen found the sole specimen east of Albany at the southwest coast of Australia at a depth of 69 m. Eucidaris galapagensis Döderlein, 1887 (Fig. 4.11 A) This species resembles very much Eucidaris thouarsii and was formerly thought to be a subspecies of that. Lessios et al. (1999) have reestablished the species E. galapagensis, being genetically well separated from E. thouarsii at the Pacific American mainland. The two species do not appear to have invaded each other’s geographic rank.

Like E. clavata, it has thick primary spines but differs in having dark secondary spines as in E. thouarsii. Distribution: The species is restricted to the Galapagos and Cocos Islands and the Clipperton Atoll off the west coast of Central and South America. Eucidaris metularia Lamarck, 1816 (Fig. 4.11 B–D) Test: Aborally flattened, diameter of test up to 30 mm. Apical system: Half the size of diameter, generally flat or slightly sunken; madreporite not larger than the other

38 

 4.1 Subclass Cidaroidea Smith, 1984

genital plates; all plates granulated, sometimes minute tubercles scattered between the granules (wearing tiny spines); a ring of larger tubercles along the distal edges of ocular and genital plates; borderlines of plates conspicuous; periproctal plates with tubercles around the anus. Ambulacra: Narrow and sinuous, about 25 % of width of interambulacra; interporiferous zone scarcely twice the width of 1 pore zone; series of marginal tubercles very regular, median space seems to be naked, but one very small tubercle is associated with each marginal tubercle. Interambulacra: Up to 6 or 7 plates per column, median space more or less covered with small tubercles, median line scarcely distinct, not sunken. Peristome: Larger than apical system, conically raised. Primary spines: More or less thick, cylindrical, shorter than diameter of test; ends distally forming a crown, but not widened; shaft covered by small granules arranged in dense series. Secondary spines: Scrobicular, marginal, and small spines strongly flattened. Color: The primary spines are distinctly banded with dark brown or purplish. The secondary spines in the interambulacra are light brown; in the ambulacra, darker brown to purplish, the midline being conspicuously light. The cleaned test is whitish with a purple or brown tint; the marginal tubercles in the ambulacra are purple to dark brown. Distribution: Eucidaris metularia is known from Mozambique and the Red Sea to the Fiji, Gilbert, and Hawaiian islands and from south Japan to the north coast of Australia at depths between 5 and 570 m. Remarks: Eucidaris metularia is the most common cidarid in the Indo-West Pacific. It differs from other cidarids of this region by its small size, color, and the short, banded, primary spines. Phyllacanthus imperialis is much larger, has longer primary spines and dark secondaries. The species of Prionocidaris have long and slender spines, more or less with thorns, and in Plococidaris verticillata, the spines have developed several whirls, and the test is greenish. Eucidaris thouarsii A. Agassiz & Desor, 1846 (Fig. 4.12 A, B) Test: Thick, high, flattened above and below. Apical disc: Flat, madreporite enlarged; all plates covered with tubercles, encircled by a more or less regular ring of larger tubercles along the outer edge; conspicuously naked margins. Ambulacra: Barely sinuous, marginal tubercles regular, smaller tubercles in interporiferous zone crowded, no naked median space. Interambulacra: Areoles rather small; round to transverse oval below ambitus; median space densely covered by tubercles with high variation in size and number: small

and regularly decreasing in size to the midline to irregular and only slightly smaller than scrobiculars, sutures often depressed. Peristome: Approximately as large as apical system. Primary spines: Nearly as long as test diameter, in less sheltered waters, they may be rather short; cylindrical or slightly spindle-shaped, distally with crown, regularly granulated or with warts; a dense cover of hair commonly hides the shaft. Secondary spines: Scrobicular spines flattened, broad with blunt tips, marginal spines a little smaller with broad ends, small spines rather short and tapering to the tip. Color: Generally, both primary and secondary spines are dark purple, the tip of the primaries is white. There may occur one or two whitish bands below the tip, especially in younger specimens or on the oral spines of adults. The spines on the apical disc are usually dark. The scrobiculars have often a broad purple brown stripe. The bare test is whitish with more or less green or green brown in the median zones in ambulacra and interambulacra; the apical plates usually not much darker than the corona. The typical naked margins around the genital plates may be lighter or darker than the plates itself, e.g. green or brown. Distribution: Eucidaris thouarsii is known along the west coast of America from the Gulf of California to Panama, but not at the offshore islands. Eucidaris tribuloides Lamarck, 1816 (Fig. 4.12 C, D) Eucidaris tribuloides resembles E. thouarsii in having the same large form with primary spines as long as the diameter of test. Test: Diameter up to 57 mm. Apical disc: Flat, madreporite slightly enlarged; beside the larger tubercles along the distal edges, all plates are densely covered with fine granules, between which numerous small tubercles are scattered. Ambulacra: Interporiferous zone with crowded smaller tubercles, no naked median space. Interambulacra: 9 to 12 plates per column, areoles rather small; median space densely covered by small tubercles decreasing in size to the midline, sutures often depressed. Peristome: Nearly as large as apical system. Primary spines: Stout, approximately as long as test diameter; in turbulent waters, shorter than in sheltered areas; cylindrical or slightly spindle-shaped, distally with crown, regularly granulated or with warts; shaft often covered by dense hair. Secondary spines: Scrobicular spines flattened, rather broad, tips blunt or even shovel-like, marginal spines in ambulacra a little smaller with broad ends, small spines short and tapering to the end.

4.1.1 Order: Cidaroida Claus, 1880 



A

B

D

 39

C

E

Fig. 4.12: (A, B) Eucidaris thouarsii. (A) Aboral side with spines, diameter of test 12 mm; Manzanillo, Mexico, Pacific. ZMH. (B) Aboral side of test, diameter 31 mm; Gulf of California, Mexico. The typical smooth edges of the apical plates are dark green. (C, D) Eucidaris tribuloides. (C) Aboral side of test, diameter 23 mm; Colombia, Caribbean. (D) Side view with spines. Diameter of test 24 mm; Colombia, Caribbean Sea. (E) Eucidaris tribuloides var. clavata. Aboral side with spines, test diameter about 35 mm; St. Helena. ZMUC.

Color: The primary spines are brown purplish, often distinctly banded. The secondaries are whitish or light brown with darker brown or reddish edges or distal ends. The cleaned test is somewhat greenish; the apical plates usually not much darker than the corona. Distribution: Eucidaris tribuloides is known from South Carolina, USA, throughout the whole Caribbean region to northern Brazil from the littoral to a depth of 450 m. It is also recorded in West Africa from the Cape Verde Islands through the Gulf of Guinea southward to Angola. Remark: The main differences between E. thouarsii (Pacific) and E. tribuloides (Caribbean) are the following: Eucidaris thouarsii shows conspicuously naked margins around the apical plates, lighter or darker than the plates itself; in E. tribuloides, there are no marked margins. Eucidaris thouarsii has dark colored scrobicular spines; in E. tribuloides, they are light with dark ends.

In E. thouarsii, the test is tinted green and the ambulacral tubercles are green as well; in E. tribuloides, they are more brownish. Genus Hesperocidaris Mortensen, 1928 Hesperocidaris is closely related to Stylocidaris. Mortensen (1928) distinguished the two genera as follows: Hesperocidaris has cylindrical primary spines that do not taper distally as in Stylocidaris. There is a thick, spongy coat of cortical hairs covering the primary spines, which is absent in Stylocidaris. Furthermore, the large globiferous pedicellariae show no limb on the stalk like in Stylocidaris. Test: Low and rather massive. Apical system: Approximately 50 % of test diameter; ocular plates exsert or with extending periproctal plates separating genital plates; genital plates similar in size.

40 

 4.1 Subclass Cidaroidea Smith, 1984

Ambulacra: Almost straight, pore zones slightly depressed; series of marginal tubercles contiguous. Interambulacra: 5–8 plates per column; areoles sunken, separated except adorally; scrobicular tubercles differentiated, extrascrobicular space narrow and densely set with heterogeneous tubercles. Peristome: Slightly smaller than apical disc, series of interambulacral plates extending to mouth opening. Primary spines: Long, slender, and not tapering; sometimes widened and flattened distally; neck and collar short, shaft set with longitudinal granuled ridges; thick coat of cortical hair present. Secondary spines: Flattened, moderately appressed. The genus consists of five species, restricted to the tropical west coast of the Americas: Hesperocidaris asteriscus H. L. Clark, 1948. Gulf of California to Panama. Hesperocidaris dubia H. L. Clark, 1907. Panama to Ecuador. Hesperocidaris houstoniana A. H. Clark, 1939. Galapagos Island. Hesperocidaris panamensis A. Agassiz, 1898. Ecuador, Cocos Island. Hesperocidaris perplexa H. L. Clark, 1907. Coast of western America. Literature: H. L. Clark 1907; Mortensen 1909; 1928; A. H. Clark 1939; 1946; H. L. Clark; 1948; Caso 1978; Lessios 2005. Hesperocidaris asteriscus H. L. Clark, 1948 (Fig. 4.13 A–C) Main characteristics of the genus. The primary spines are longer than the diameter of test, cylindrical, set with small bumps. This species differs from the other species of Hesperocidaris by the naked margins of the apical plates, marked distinctly by colored or lighter lines around the genital plates. It gives the apical system a conspicuous star-shaped appearance. Color: The primary spines are dark to light brown with a more or less bright red or rose collar, secondary spines often with dark stripe. Distribution: This species is recorded from Baja ­California and the Gulf of California to Panama at a depth of 2 to 183 m. Hesperocidaris dubia H. L. Clark, 1907 (Fig. 4.13 D) Test: Low, flattened below, apical disc elevated. Apical system: Densely set with tubercles, ocular plates to a variable degree insert. Ambulacra: About 40 % of interambulacra; interporiferous zone twice the width of pore zone; marginal series regular and contiguous, inner tubercle at lower edge of each plate, forming also regular rows; midzone naked and rather sunken.

Interambulacra: Shallow areoles, below the ambitus transversely oval; scrobicular ring not prominent, extrascrobicular space with only one series of tubercles, about half the width of an areole; conspicuously bare median zone. Primary spines: In length, scarcely more than the diameter of test; shaft with 12–14 longitudinal ridges set with low, rounded granules; oral primaries simple. Secondary spines: Scrobiculars flat, usually widened at the tip; marginal spines of about same size, but narrower, sometimes thickened at the point; small spines simply tapering. Color: Test green; pore zones and median space in ambulacra und interambulacra white, apical system, mainly the periproct, dark brown; primary spines greenish-brown, tip white; secondary spines with white green edges and purple median stripe. Distribution: Recorded in the East Pacific from Panama to the coast of Ecuador. Depth 64 to 205 m. Hesperocidaris houstoniana A. H. Clark, 1938 (Fig. 4.14 A, B) This species is closely related to Hesperocidaris panamensis. It differs in the shape of its primary spines. In H. houstonianus, they are thickened above the base tapering to the distal end; in H. panamensis, they are cylindrical. The two species are also distinguished by the interporiferous zone: in H. houstoniana, it is densely set with two regular rows of marginal and inner tubercles; in H. panamensis, there is a naked midline. Scrobicular spines: Strongly flattened, broadly truncated or convex; marginal spines narrower. Color: Bright brown red, tips of secondary spines sometimes purplish, primary spines with diffuse lighter bands. Denuded test whitish with green or yellowish tinge. Distribution: Reported from the Galapagos Islands at a depth of 91 m. Hesperocidaris panamensis A. Agassiz, 1898 (Fig. 4.14 C) Test: Distinctly low; maximum reported test diameter 49 mm. Apical system: Ocular plates broadly exsert, margins may be conspicuous. Ambulacra: In width about 40 % of interambulacra; regular series of marginal tubercles and small tubercles, median space naked, scarcely sunken; pores large and equal-sized. Interambulacra: Shallow areoles, between the upper ones space for a row of extrascrobicular tubercles; scrobicular tubercles hardly larger than other secondaries, which gradually decrease in size toward the naked, slightly sunken median zone.

4.1.1 Order: Cidaroida Claus, 1880 



A

 41

B

D C

Fig. 4.13: (A–C) Hesperocidaris asteriscus. Aboral side of test, diameter 23 mm; Gulf of Chiriqui, Panama. The naked lines in the apical disc are distinct. (B) Side view. (C) Close-up of aboral side, diameter of test 21 mm. (D) Hesperocidaris dubia. Aboral side with spines, diameter of test 29 mm; Bahia Honda, Pacific coast of Panama. ZMUC.

Primary spines: About 1–1.5 the test diameter, rather slender, cylindrical, or slightly widened; shaft closely set with low, rounded granules arranged in 16–18 rows, forming ridges only near the distal end; neck smooth and somewhat shiny; oral primaries simple, nearly smooth with long collar. Secondary spines: Scrobiculars slender, flattened, not tapering, and not really appressed; marginal spines of same length, but more slender. Color: Test creamy white with small more or less distinct brown spots; primary spines beige to brown, secondary spines uniformly dark red brown (Lessios 2005 reported

uniform green white secondaries); in young specimens, the collar tends to be orange red, it becomes darker as it gets older; naked test with green or red brown tint, apical plates red brown to rose, sometimes with lighter edges. Distribution: The species is known from Ecuador, the Cocos Island, and Panama. Bathymetric range 55 to 274 m. Hesperocidaris perplexa Clark, 1907 (Fig. 4.14 D) Ambulacra: Inner space of interporiferous zone rather broad and densely set with small, irregularly arranged tubercles.

42 

 4.1 Subclass Cidaroidea Smith, 1984

A

C

B

D

Fig. 4.14: (A, B) Hesperocidaris houstoniana. (A) Aboral side with spines. Diameter of test 19 mm; Galapagos Islands. ZMUC ECH 164. The spines are stout and thickened at the base. (B) Oral side. (C) Hesperocidaris panamensis. Oral side with spines. Diameter of test about 30 mm; Cocos Island, East Pacific. ZMUC. (D) Hesperocidaris perplexa. Aboral side, diameter with spines 115 mm; Gulf of California. The primary spines hardly exceed the diameter of test.

Interambulacra: Scrobicular ring inconspicuous, areoles rather small, upper ones separated also by extrascrobicular tubercles. Primary spines: Barely as long as test diameter, those at the ambitus flattened and widened. Color: Test and spines greenish-gray, collar and neck olive green; secondary spines with purple stripe.

Distribution: reported from off the west coast of America from the Gulf of California to Ecuador at a depth of 13 to 1,500 m. Genus Kionocidaris Mortensen, 1932 This monospecific genus is characterized by thick primary spines with low smooth ridges.



4.1.1 Order: Cidaroida Claus, 1880 

 43

Kionocidaris striata Mortensen, 1932 (Fig. 4.15 A, B) Test: Moderately low, flattened above and below; the two only known specimens 27 mm in diameter. Apical system: Both genital and ocular plates more or less bare, tubercles along the inner edge elongated; madreporite not enlarged, pores in females larger than in males; ocular plates insert; periproct slightly raised. Ambulacra: Narrow, sinuate; interporiferous zone twice the width of pore zone; marginal tubercles regular, contiguous; inner space narrow, leaving only space for a single, incomplete series of small tubercles, placed alternately on one or the other side of the midline. Interambulacra: Areoles not at all deepened, well ­separated, only lowermost confluent but not oval; 2 to 3 uppermost primary tubercles large, adapically crenulated, tubercles decreasing in size toward the peristome; scrobicular tubercles scarcely larger than marginal tubercles, edge of areole not at all raised; extrascrobicular space half the width of an areole, set with a few scattered small tubercles, midline naked and sunken. Peristome: Of same size as apical system, conspicuously raised. Primary spines: Thick and solid having a column-like appearance, gently tapering into a simple end; perfectly smooth, but striated by about 25 fine, low ridges without any serrations; surface between the ridges finely porous; oral primaries simple, slightly flattened, striate, but not serrated. Secondary spines: Scrobiculars simple, flat, slightly tapering into a rounded point, ca. 4  mm long; marginal spines 2 mm long. Color: In general, the test is white with the upper primary tubercles creamy. The apical plates may be creamy or light olive. There is a small darker spot in the middle of each genital plate. The primary spines are cream to white with very faint bands of pink, the secondaries white with a narrow median stripe in pale greenish-olive. The apical system may sometimes have a uniform olive color, continuing as a tinge along the ambulacra toward the ambitus. Occurrence: Off KwaZulu-Natal, South Africa. Depth 126 m. Mortensen (1932) had two specimens on hand, which differ to some degree. A. M. Clark et  al. (1976) referred to these specimens; obviously, no other specimens being recorded.

Ambulacra: Faintly sinuous; pore pairs hardly conjugate with narrow interporal partitions, pore zones sunken; series of marginal tubercles contiguous, inner series of smaller tubercles present. Interambulacra: 7–9 plates per column; primary tubercles may be faintly crenulated on adapical side; scrobicular tubercles slightly differentiated; extrascrobicular space narrow; extrascrobicular tubercles gradually decreasing in size toward the slightly sunken midline. Primary spines: Long and cylindrical; collar and neck short, shaft faintly ribbed with a crust of cortical hair making the surface appear smooth, tip with small crown. Secondary spines: Slightly appressed. The genus includes two species: Lissocidaris fusca Mortensen, 1939. Maldives, Indian Ocean. Lissocidaris xanthe Coppard & van Noordenburg, 2007. Philippines.

Genus Lissocidaris Mortensen, 1939 Test: High and rather massive. Apical system: About 40 % of test diameter; ocular plates just insert; genital plates of same size; all plates densely set with uniform granules.

Lissocidaris xanthe Coppard & van Noordenburg, 2007 (Fig. 4.15 E, F) Test: Globular to more or less flattened. Apical system: All plates densely covered by small ­tubercles, gonopores relatively small.

Lissocidaris fusca Mortensen, 1939 (Fig. 4.15 C, D) Test: Almost spherical, flattened above. Apical system: In width about 40 % of test diameter; ocular plates all narrowly insert. Ambulacra: Rather broad; marginal tubercles quite regular, inner space with two or three smaller tubercles per plate. Interambulacra: Areoles well separated; fine incised lines on uppermost plates continuing on areoles. Peristome: Of same size as apical system. Primary spines: Slender, almost cylindrical, scarcely tapering; surface smooth but not shining, about 20–35 ridges, the furrows between them filled with crests of cortical hair; neck about 3 mm long, shining, twice the length of collar; oral primaries broad and flattened. Secondary spines: Scrobiculars slender, with rounded points; marginal spines slightly shorter and more slender; other small spines very narrow, erect. Color: Generally uniform dark brown, primary spines creamy white, neck light pink, collar darker. Denuded test with dark brown apical plates more or less continuing over the interambulacra. Distribution: The species is recorded from the Maldives, Indian Ocean. Depth 229 m.

44 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

C

E

D

F



Ambulacra: Regular row of marginal tubercles, two inner tubercles placed one above the other. Interambulacra: Areoles separated by at least two rows of scrobicular tubercles, uppermost areoles sometimes confluent; horizontal sutures distinct. Primary spines: In length, more than twice the diameter of test; tapering into a blunt tip; smooth and shiny surface caused by a closed crest of cortical hair between 22 low, longitudinal ridges; oral primaries with serrated edges. Scrobicular spines: Widened at the base and tapering; ridged; other secondary spines slender. Pedicellariae: Globiferous ones with longitudinal opening beneath the terminal tooth. Color: In live specimens, test and secondaries are yellowish-brown; the primary spines, pure white. The ­ denuded test is white or occasionally light rose with red brown apical plates, the color being more or less concentrated to the center. Distribution: Mactan Island, Philippines. Depth 150 to 350 m. Genus Phyllacanthus Brandt, 1835 Smith & Wright (1989) established a separated tribe within the family Cidaridae for the genus Phyllacanthus. Unlike most other cidarids, it is characterized by having two series of pore pairs perforating the peristomial ambulacral plates (see Fig. 4.17 G). In the other, there are rows of ­ eristome. simple ambulacral pores throughout the whole p Test: Strong, large form; flattened, peristome may be inflated. Apical system: Relatively small, less than 40 % of test diameter; ocular plates exsert; madreporite larger than other genital plates; all plates densely set with tubercles. Ambulacra: Sinuous; pore pairs widely separated and conjugate; marginal tubercles more or less regular, inner space densely covered with slightly smaller secondary tubercles. Interambulacra: 5–9 plates per column; areoles slightly sunken, wider than long except adapically, well separated also adorally; scrobicular tubercles strongly differentiated, extrascrobicular space narrow, set with heterogeneous tubercles. Peristome: Larger than apical system, double pores in each ambulacral series, interambulacral plates do not reach mouth opening.

4.1.1 Order: Cidaroida Claus, 1880 

 45

Primary spines: Stout and often fusiform, tapering to a blunt point, sometimes with crown-like tip, shaft set with more or less regular granules. Secondary spines: Flattened with parallel sides, very strongly appressed. Six species are included in this genus: Phyllacanthus dubius Brandt, 1935. Bonin Islands. Phyllacanthus forcipulatus Mortensen, 1936. Indian Ocean to Philippines. Phyllacanthus imperialis Lamarck, 1816. Indo-Pacific. Phyllacanthus irregularis Mortensen, 1918. Southwest ­Australia, littoral. Phyllacanthus longispinus Mortensen, 1918. Northwest Australia and around Darwin. Phyllacanthus magnificus H. L. Clark, 1914. Western ­Australia from Fremantle to Shark Bay. Phyllacanthus parvispinus Tenison-Woods, 1880. Southeast Australia and Tasmania. Literature: Clark 1914; Mortensen 1918, 1928, 1936; A. M. Clark & Rowe 1971; Hoggett & Rowe 1986; Rowe & Hoggett 1986; Smith & Wright 1989; Rowe & Gates 1995; Miskelly 2002. Phyllacanthus dubius Brandt, 1935 (Fig. 4.16 A–C) Test: Diameter not much more than 60 mm. Apical system: Ocular plates sometimes with narrow ­prolongations reaching the periproct. Ambulacra: Interporiferous zone slightly wider than pore zone; marginal tubercles very regular, inner space narrow, set with a row of smaller, alternating tubercles; pore zones depressed. Interambulacra: Areoles shallow, median space narrow, in width a third of areole, filled with small secondary tubercles. Peristome: Elevated. Primary spines: About as long as diameter of test, rather slender, cylindrical, usually slightly thicker at the base; shaft ornamented with 18–20 regular series of granules, distally forming distinct ridges; oral primaries simple, short, ridged over the whole length. Secondary spines: Scrobiculars 5–7  mm long, flat, ­tapering to a straight-cut end; marginal spines 2–3  mm long, with parallel sides. Color: Denuded test white with pink tint; primary spines light purple brown, secondary spines dark purple.

◂ Fig. 4.15: (A, B) Kionocidaris striata. Side view with spines, diameter of test 27 mm; off KwaZulu-Natal, South Africa. ZMUC ECH 313.

(B) Side view of denuded part of test. (C, D) Lissocidaris fusca. (C) Close-up of denuded part of test, diameter of test 50 mm; off the Maldives, Indian Ocean. (C) The Trustees of the Natural History Museum London (photo by Harry Taylor). (D) Aboral side partly with spines. (E, F) Lissocidaris xanthe. (E) Aboral side of test, diameter 16 mm; Philippines (photo by Bas van der Steld). (F) Close-up of aboral side, diameter of test 36 mm; Mactan Island, Philippines (photo by W. Clarenbach).

46 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

C

D

Fig. 4.16: (A–C) Phyllacanthus dubius. (A) Aboral side of test, diameter 47 mm; Bonin Islands, Japan. ZMUC. (B) Side view. (C) Aboral side with spines, diameter of test 36 mm; Bonin Islands, Japan. ZMUC. The secondary spines are strongly appressed. (D) Phyllacanthus forcipulatus. Aboral side with spines. Diameter of test about 60 mm; Balut Island, Philippines (photo by W. Clarenbach). The primary spines are covered with coarse longitudinal ridges.

Distribution: The species is restricted to the littoral of the Bonin Islands, Japan. Remark: In general appearance, this species resembles Phyllacanthus imperialis, but it differs by its distinctly ridged granules along the primary spines; P. imperialis has only microscopic granules. Phyllacanthus forcipulatus Mortensen, 1937 (Fig. 4.16 D) Test: Diameter may reach 58 mm. Primary spines: On the aboral side, rather long, up to twice the diameter of test, slender, cylindrical, scarcely

tapering, covered with about 12 lowly granuled ridges, becoming a little more prominent distally forming a small crown; space between the ridges covered by a coat of low, coarse cortical hair; neck very short, collar about 3  mm long; oral primaries slender and longitudinally ridged. Secondary spines: About 6–7  mm long, flattened, with rounded point; ambulacral spines scale-like. Color: Test and secondary spines light brown with a faint pink tint on the scrobicular spines. The primary spines are brown to red brown with a light band near the tip;



s­ ometimes, there may be a second band; the ridges are somewhat darker. The denuded test is white. Distribution: This species is known in the Indian Ocean and the Philippines in deeper water. Remark: Phyllacanthus forcipulatus is well distinguished from the other species of Phyllacanthus by the more slender primary spines, which have much fewer ridges. Phyllacanthus imperialis Lamarck, 1816 (Fig. 4.17 A–E) Test: High, upper, and lower side flattened; maximum diameter of test about 80 mm. Apical system: About one third of test diameter, ocular plates small. Ambulacra: Interporiferous zones only a little broader than 1 pore zone, marginal tubercles very regular, median space filled by 2 to 4 less regular series of small tubercles; pore pairs connected by shallow furrow; pore zones depressed. Interambulacra: 6–7 plates in one column, tubercles large, areoles scarcely depressed, separated only by the scrobicular tubercles, which show a very characteristic appearance; median zone densely covered with tubercles in fairly regular horizontal rows, separated by fine, depressed lines running over the median sutures. Peristome: Much larger than the apical system. Primary spines: Thick, cylindrical, or slightly spindleshaped, about as long as the test diameter; shaft with very small, indistinct, close series of granules; ending distally in a crown. Secondary spines: Flattened and with very fine ridges, scrobicular ones broad and much larger than marginal ones, strongly appressed, small ones short. Color: Primary spines chocolate brown or lighter, if they are not encrusted by other organisms; in young specimens banded; secondaries dark brown to dark purple; bare test light lilac to slightly purple brown with white areoles and tubercles. Habitat: This species is a typical inhabitant of the littoral with turbulent water. With its thick primary spines, it is able to wedge between the coral blocks holding against the surf. Remark: Phyllacanthus imperialis differs from the other common cidarids of the region by its thick, long spines: Prionocidaris baculosa has slender ones; in Plococidaris verticillata, they are equipped with whirls, and in the small Eucidaris metularia, they are short and stout. Distribution: Phyllacanthus imperialis is found throughout the whole Indo-Pacific from the Red Sea and Madagascar to the Tonga Islands, from the Riu-Kiu Islands to Australia at depths of about 5 to 70 m.

4.1.1 Order: Cidaroida Claus, 1880 

 47

Phyllacanthus irregularis Mortensen, 1928 (Fig. 4.18 A–C) This species differs from Phyllacanthus imperialis mainly by the irregularly arranged ambulacral tubercles set with spines of varying length, and by the size of the test, which can reach a diameter of 110 mm. Primary spines: Rather short, only one half or two thirds of the horizontal diameter and irregularly granulated. Secondary spines: Pointed distally; in Phyllacanthus imperialis and P. parvispinus, they are parallel-sided with a blunt end. Color: The are usually dark purple with a white band in the distal part (not always visible on spines overgrown with encrusting organisms), the secondary spines are dark brown to purple. The bare test is white with a purple, or sometimes with a green tint. Distribution: The species occurs around southern Australia from St. Vincent Bay, South Australia, to the Abrolhos Island on the west coast, living in the littoral zone. Phyllacanthus longispinus Mortensen, 1918 (Fig. 4.18 D) Test: Flattened above and below; maximum recorded diameter 90 mm. Apical system: About 35–40 % of test diameter; ocular plates widely exsert; gonopores usually on top of conical elevation. Ambulacra: Width less than 20 % of width of interambulacrum. Interambulacra: Plates and areoles large (compared to Phyllacanthus parvispinus), median area only one third in width of an areole. Primary spines: In length, about 1.3 the diameter of test; comparatively slender, 6–7 mm at the base, not fusiform, slightly tapering to the faintly flaring end; shaft with about 20 series of granules; collar short, neck smooth; oral primaries club-shaped and fluted over the whole length. Secondary spines: Scrobiculars scale-like, marginal spines slender, cylindrical, hardly flattened. Color: Denuded test light olive green with white areoles, adapically with pink tint; primary spines gray green without bands; secondary spines dark purple. Distribution: Known from Western Australia around the north coast to Queensland. Bathymetric range: from the littoral to a depth of 62 m. Phyllacanthus magnificus H. L. Clark, 1914 Test: Nearly globular; horizontal diameter may reach 92 mm. Apical system: 30–36 % of test diameter; madreporite strongly enlarged; ring of larger tubercles surrounding the gonopores.

48 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

E

D

F

G

test

am ia

ia

mo

4.1.1 Order: Cidaroida Claus, 1880 



A

B

C

D

 49

Fig. 4.18: (A–C) Phyllacanthus irregularis. (A) Aboral side of test, diameter 105 mm, height 64 mm; Rottnest Island, Western Australia. (B) Close-up of ambulacrum. The marginal tubercles are irregular in size. (C) Aboral side with spines; test diameter 76 mm; southwest Australia. ZMH. (D) Phyllacanthus longispina. Side view with spines, test diameter 90 mm; northwestern Australia. ZMUC ECH 570.

Ambulacra: In width about 30 % of interambulacra; regular series of marginal tubercles and a second series of secondary tubercles half that size. Interambulacra: Areoles transverse oval at the ambitus and below, slightly confluent only the lowermost plates; median area two third of width of areole, covered by

small, uniform secondary tubercles, arranged in distinct horizontal series separated by fine furrows. Peristome: Of same size as apical system. Primary spines: In length, less than test diameter; in a specimen of 92 mm in diameter, the longest spine ­measures 75 mm, 10 mm thick at the base, tapering to 5 mm at the tip; set with

◂ Fig. 4.17: (A–E) Phyllacanthus imperialis. (A) Aboral side of test, diameter 66 mm; Negros, Philippines. (B) Oral side. (C) Aboral side with

spines, diameter of test 44 mm; Negros, Philippines. (D) Close-up of apical disc. Scale: 20 mm. The secondary spines are strongly appressed. (E) Close-up of ambulacrum and interambulacrum, scale 10 mm. (F) Median space of interambulacrum. The scrobicular tubercles have a characteristic appearance. Scale: 2 mm. Modified after Mortensen (1928). (G) Phyllacanthus parvispinus. One ambulacrum on the peristome: the pore pairs are arranged biserially. amb = ambulacrum, interamb = Interambulacrum, mo = mouth below. Scale: 6 mm (Mortensen 1928).

50 

 4.1 Subclass Cidaroidea Smith, 1984 Phyllacanthus parvispinus Tenison-Woods, 1880 (Fig. 4.19 A, B) This species is characterized by having irregularly arranged granules on its primary spines, regular rows occur only near the tip. It differs from Phyllacanthus irregularis by having scale-shaped secondaries in ambulacra and apically. It differs from P. imperialis by the coarser granules. Phyllacanthus parvispinus has more interambulacral plates set with primary spines in one column than P. imperialis comparing equal-sized specimens (50–70 mm in diameter), the former 8–10, the latter 7–8. The bare test is more or less tinted greenish in contrast to the light purplish of P. imperialis. Distribution: Phyllacanthus parvispinus is found around the east coast of Australia from northern Queensland to

irregular series of granules, ­distally passing into 24–36 longitudinal ridges; collar about 3 mm, short neck smooth; oral primaries stout, somewhat flaring at the tip, not ridged. Secondary spines: Scrobiculars with a usually conspicuous keel on the upper side of the spine forming basally a small hump decreasing in height toward the tip; m ­ arginal spines flattened; not pointed, small spines scale-like, appressed. Color: Test with secondary spines deep red brown, primary spines purple red, the collar yellow brown; denuded test with faint pink tinge to deep pink. Distribution: This species is restricted to Western Australia between Fremantle and Shark Bay, living probably in deeper water.

A

B

C D

Fig. 4.19: A, B. Phyllacanthus parvispinus. (A) Side view of test, diameter 56 mm; Port Jackson, New South Wales, Australia. ZMUC. (B) Phyllacanthus parvispinus. Side view with spines, diameter of test 28 mm; Sydney Harbour, New South Wales, Australia. (C, D) Plococidaris verticillata. Aboral side with spines, test diameter 23 mm; Siquijor, Philippines. (D) Aboral side of test, diameter 29 mm; Negros, Philippines.



Tasmania and also at the Kermadec Islands, at depth from 0 to 80 m. Only in Queensland, Phyllacanthus imperialis overlaps in occurrence with P. parvispinus. Genus Plococidaris Mortensen, 1909 The monospecific genus Plococidaris is characterized by having primary spines with several, very typical whorls. Plococidaris verticillata Lamarck, 1816 (Fig. 4.19 C, D) Test: Flattened above and below, circumference round to slightly pentagonal, diameter of test reaches maximal 40 mm. Apical system: About 45–50 % of diameter; terminal plates in larger specimens all insert; genital and ocular plates look almost naked, but they are finely granulated, only with a series of tubercles along the outer and inner edge; periproct sparsely covered with tubercles. Ambulacra: Slightly sinuate; pore pairs conjugate; regular series of marginal tubercles, continuous; inside the marginal series two more or less regular series of smaller ones, remaining median space naked and sunken. Interambulacra: Areoles separated, not depressed; scrobicular circle prominent, outside this ring alternating smaller tubercles; median zone naked and slightly sunken. Peristome: About the same size as apical disc, conically raised. Primary spines: In length, scarcely reaching diameter of test; with 3 or 4 very characteristic whorls of prominent, sharp ridges, like crowns one above the other, the distal point ending in a smaller crown; between the whorls, the shaft is covered by small thorns or prominent spots, more or less regularly arranged; oral primaries short and lacking whorls. Secondary spines: Scrobiculars broad; marginal spines in the ambulacra flattened and rather narrow; the small spines of the apical system more leaf-shaped. Color: In life, the test is generally green or brown green, the primary spines more or less banded, the whorls white. The secondary spines are white with green on the apical system and much darker in the ambulacra. The bare test is white to pale green, pore zones in ambulacra dark green, the median line conspicuously white. In the interambulacra, the median zones are more or less dark green as well or olive green, also the genital plates and sometimes all heads of tubercles. The dark green or brown genital plates form a star in contrast to the lighter ocular plates. Remarks: The typical shape of the primary spines makes this species unique among all other cidarids of the region. The bare test may be recognized by the more or less intensive green color of the test, especially in the apical system, where the darker genital plates form a distinct star. The structure of the test is undistinguishable from Prionocidaris.

4.1.1 Order: Cidaroida Claus, 1880 

 51

Distribution: This species is known all over the IndoPacific region, from Zanzibar, East Africa, to the Fiji and Hawaiian Islands, from southern Japan to the Australian east coast. It lives from the ebb zone to a depth of 50 m. Literature: A. M. Clark & Rowe 1971; Rowe & Gates 1995. (In both papers Plococidaris is synonymized with the genus Prionocidaris, despite the very different primary spines). Genus Prionocidaris A. Agassiz, 1863 The genus is characterized by spots and stripes on the collar and neck of the primary spines and by its transverse oval and confluent areoles. Test: Usually rather tall. Apical system: Ocular plates mostly broadly insert; all plates more or less densely covered with small tubercles, larger ones along the inner and outer edges of the plates. Ambulacra: Pore pairs conjugate, at least subconjugate, pores widely separated. Interambulacra: Areoles usually transversely oval, confluent, sunken. Peristome: Slightly smaller than apical disc. Primary spines: Long and slender; collar and neck short, typically spotted or with lines. Secondary spines: Flattened, very slender, not appressed. With nine species, the genus is widely distributed throughout the Indo-Pacific: Prionocidaris australis Ramsay, 1885. Philippines to ­Australia. Prionocidaris baculosa Lamarck, 1816. Indo-West Pacific. Prionocidaris bispinosa Lamarck, 1816. Philippines to ­Australia. Prionocidaris callista Rowe & Hoggett, 1886. East coast of Australia. Prionocidaris glandulosa de Meijere, 1904. Malayan Archipelago and Philippines. Prionocidaris hawaiiensis A. Agassiz & H. L. Clark, 1907. Hawaii. Prionocidaris pistillaris Lamarck, 1816. East Africa to ­Seychelles. Prionocidaris popiae Hoggett & Rowe, 1986. New ­Caledonia, Vanuatu. Prionocidaris thomasi A. Agassiz & H. L. Clark, 1907. Hawaii. The species can be distinguished mainly by the sculpture of the primary spines and the coloration of the collar. It is much more difficult to separate their bare tests. Literature: A. Agassiz & H. L. Clark 1907; Mortensen 1928; A. M. Clark & Rowe 1971; Guille et  al. 1986; Hoggett & Rowe 1986; Rowe & Gates 1995; Rowe & Hoggett 1986; Shigei 1986; Miskelly 2002.

52 

 4.1 Subclass Cidaroidea Smith, 1984

Prionocidaris australis

Prionocidaris baculosa

White spots on collar of primary spines Malayan and Philippine waters to east Australia

Prionocidaris bispinosa

Prionocidaris callista

Prionocidaris pistillaris

Dark purplish spots on collar No spots on collar

Light spots on collar

Dark lines on collar

Red Sea and East Africa to Malayan Archipelago; Japan to western Australia

East Australia from south Mauritius to eastern Queensland to Montague South Africa Island, New South Wales

Ceylon to northwest Australia

Prionocidaris australis Ramsay, 1885 (Fig. 4.20) Test: Slightly flattened on the upper side, rather s­trongly incurved at the peristomial edge; maximum diameter 68 mm. Apical system: All apical plates densely tuberculated. Ambulacra: Sinuate; marginal tubercles very regular, immediately inside the marginal tubercles much smaller ones forming more or less regular series, decreasing in size and number toward the median line; pores conjugate. Interambulacra: Relatively few plates in one column, about 7 plates; ring of scrobicular tubercles often rudimentary at upper or lower edge; remaining median space of plates with small scattered tubercles, median sutures scarcely sunken. Peristome: Slightly sunken, approximately same size as apical system. Primary spines: Varying considerably in length, from half to two thirds of test diameter in adult, in young specimens, much longer; lower part of shaft more or less flattened, upper side generally with prominent series of large thorns, downward side with low ridges of granules; distally gently tapering, thorns decreasing in size, point often more or less flaring into an irregular crown; oral primary spines are very short. Secondary spines: Scrobicular spines quite slender, distal end rounded; marginal ones half the length, more slender, with rounded ends as well; small spines almost rod-shaped, covering the periproct like a cone. Color: The primary spines in young specimens are dark purple, in adults more light green, often banded with purple. The collar is covered with white spots, sometimes the spots continue a little way onto the shaft. The scrobicular spines often show a longitudinal stripe in green or brown purple. The denuded test is white, purplish tinted at the median zones in the interambulacra, the ambulacra conspicuously purple. The apical plates are also purple, often with some green. Distribution: Prionocidaris australis is known from the Philippines, Indonesia, and in Australia from Queensland along the east coast to Sydney at depths of about 10 to 145 m. Remarks: This species differs from Prionocidaris callista by the purple color of the ambulacra and by the less numerous Prionocidaris interambulacral plates. Compared with ­ ­baculosa, P. australis has longer thorns on the primary spines and white spots on the collar, not dark ones.

Prionocidaris baculosa Lamarck, 1816 (Fig. 4.21) Test: Slightly flattened above and below, ambitus round or slightly pentagonal, horizontal diameter of test may reach more than 80 mm. Apical system: About 45 % of test diameter. Ambulacra: Marginal series of tubercles very regular, small, and continuous; inside the marginal series, as a rule, two double series of much smaller tubercles, median line sometimes visible. Interambulacra: Scrobicular tubercles prominent; outside the circle, a few tubercles about half that size, alternating with the former; median space closely covered with very small tubercles, leaving sometimes a narrow, naked zigzag line along the slightly sunken sutures. Peristome: Protruding. Primary spines: Very variable: in length from less than diameter of test to about 1.7; in shape from almost cylindrical to spindle-like, tapering distally or with the point more or less widened, banded or not; shaft very closely set with very small, uniform thorns, serially arranged only in the distal third of spines, the spindle-like primaries can be conspicuously thorny in the lower third of the shaft, but only on the upper side; oral primaries simple, mostly straight cut. Secondary spines: Scrobiculars long, slender, and flattened; marginal spines also slender; small ones like very tiny pins. Color: The denuded test has dark purple or brown apical plates and ambulacra, the median spaces in ambulacra and interambulacra are light brown to green; primary spines dark purplish brown to light brown, irregularly banded, collar always with purple spots; the secondaries usually purple brown, or light with a dark median stripe. Distribution: This species is common in the Indian Ocean from the Red Sea to Mauritius and Ceylon, also in Philippine and Indonesian waters, and from Japan to the west coast of Australia from the shore to a depth of about 200 m. Remarks: A. Agassiz (1873) described a subspecies ­Prionocidaris baculosa annulifera with banded primary spines, but Mortensen (1928) stated that are intermediate forms to the typical P. baculosa having rather uniformly dark spines. Prionocidaris baculosa can be distinguished from ­Prionocidaris pistillaris by the spots on the collar, the latter having stripes. From Prionocidaris australis, it

4.1.1 Order: Cidaroida Claus, 1880 



 53

A

B

C

D

E

Fig. 4.20: Prionocidaris australis. (A) Close-up of aboral side with spines, diameter of test about 51 mm; off Balina, New South Wales, Australia. (B) Aboral side of test, diameter 43 mm; Sydney Harbour, New South Wales, Australia. (C) Oral side of test. (D) Aboral side, diameter with spines 124 mm; Vaucluse Bay, Sydney, Australia. (E) Oral side with spines.

differs in the shape of the spines, which are less thorny. The bare tests of the species are difficult to distinguish. Prionocidaris bispinosa Lamarck, 1816 (Fig. 4.22 A, B) Test: Rather low, flattened above and below; maximum diameter 78 mm. Apical system: Ocular plates mostly all insert, but not rarely A II and A III may be exsert; all plates more or less densely covered by very small tubercles, larger

ones at the inner and outer edges and on the periproctal plates. Ambulacra: Interporiferous zone twice the width of 1 pore zone; marginal series of tubercles very regular, contiguous; median zone with some inner t­ubercles in more or less regular series, in larger specimens crowded; pore pairs conjugate, rather distant from each other. Interambulacra: Ring of scrobicular tubercles fairly conspicuous, alternating ones of half the size encircling the

54 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

C

E

E D

1

2 3 6 4

5

Fig. 4.21: Prionocidaris baculosa: (A) Aboral side of test, diameter 45 mm; Negros, Philippines. (B) Close-up of interambulacrum, diameter of test 60 mm, height 41 mm; Philippines (coll. C. Neumann). (C) Ambulacral plates: the pores are conjugate, connected by a distinct groove and separated from the next pair by a sharp ridge. Scale: 2 mm (Mortensen 1928). (D) Aboral side with spines, diameter of test about 37 mm, longest spine 59 mm; Philippines. (E) One to five diverse, very different looking primary spines: (1) spine with encrusting organisms (Philippines); (2) the long, banded, and pointed spine comes from the ambitus, the two shorter ones with the widened ends are from the oral side (Philippines); (3) dark, strongly spindle-shaped spine with coarse thorns at the lower part of the shaft (Ile de la Réunion); (4) two spindle-shaped spines with conspicuous thorns at the upper side, the underside has only granules (Japan); (5) two dark spines, only slightly tapering distally and with a few small thorns (Philippines).

4.1.1 Order: Cidaroida Claus, 1880 



A

 55

B

C

D

Fig. 4.22: (A, B) Prionocidais bispinosa. (A) Close-up of aboral side with spines, diameter of test about 43 mm; Singapore. ZMH. (B) Aboral side of test with spines, diameter of test 41 mm, longest spine 39 mm; Shark Bay, Western Australia. (C, D) Prionocidaris callista. (C) Aboral side of test, diameter 53 mm; Sydney Harbour, New South Wales, Australia. (D) Side view, diameter with spines 240 mm; Sydney Harbour, New South Wales, Australia. The secondary spines are conspicuously bright red.

former; smaller tubercles decreasing in size toward the vertical sutures. Peristome: Somewhat smaller than apical system. Primary spines: Cylindrical, longest up to 1.5 of test diameter, usually less; shaft very variable from almost smooth, through having small thorns in lateral series to very coarse thorns in more or less distinct whorls; tapering to the tip, at the tip often flaring into a thorny

crown; collar widened at the base; oral primaries flattened and ending with a knob or crown. Secondary spines: Scrobicular ones flattened; marginal ones very narrow and pointed, small spines pointed as well. Color: The primary spines are white or banded in green with purple red, the collar uniformly pink or brown. The scrobicular spines are pink at the base, distally yellow or green. The ambulacral spines and the small ones

56 

 4.1 Subclass Cidaroidea Smith, 1984

are rather dark. The bare test show a grayish white; the heads of tubercles being brightly pink. Sometimes, the ambulacra and the apical plates may be dark violet. Distribution: This species occurs in the Philippines and in the Malayan Archipelago, ranging as far as Ceylon and southwest Australia and eastward to Queensland, northeast Australia, and the Bismarck Archipelago, Papua New Guinea. It lives at depths of 4 to 50 m. Remarks: Prionocidaris bispinosa and Prionocidaris baculosa are difficult to distinguish due to the large degree of variability in both species. They differ in the color of the collar of the primary spines: in P. baculosa, there are dark purple spots on creamy to brown background; in P. bispinosa, the pink red collar lacks spots at all. The bare tests are hardly to distinguish. Prionocidaris callista Rowe & Hoggett, 1986 (Fig. 4.22 C, D) This recently established species is very similar to Prionocidaris australis. It differs mainly in the following characteristics: –– The ambulacra are fawn or pale green rather than purplish; the interporiferous zone is more densely tuberculated. –– The median zone of the interambulacra is more densely tuberculated. –– The number of interambulacral plates in one column is higher  – at a horizontal diameter of 52  mm, there are 9 to 10 plates. –– The color of the secondary spines is more red. –– As in P. australis, the collar of the primary spines shows lighter spots on brown maroon ground. Distribution: Prionocidaris callista is restricted to the east coast of Australia from Mackay, Queensland to ­Montague Island, New South Wales, at Lord Howe Island, the Norfolk Island, and New Caledonia. It is reported from depths of 2 to 275 m. Prionocidaris glandulosa de Meijere, 1904 (Fig. 4.23 A, B) Test: Low, sides strongly arched, flattened above and below, diameter up to 27 mm. Apical plates: scattered small tubercles, anal plates may be raised.

Ambulacra: In width about 30 % of interambulacra, regular series of marginal tubercles and much smaller inner tubercles; pore pairs very slightly conjugate. Interambulacra: Only 5–6 plates per column; narrow median zone. Primary spines: 2–3 times the test diameter, slender, tapering to a simple point; collar long, about 3–5  mm; shaft set with about ten series of rather coarse thorns, sometimes the lateral rows carry longer thorns; oral primaries slender, serrations indistinct, often distally flaring. Secondary spines: Scrobiculars simply pointed and flattened, slightly appressed; marginal spines of same shape, but slightly shorter; bag of glandular skin at the base of the secondaries. Color: Denuded test white, with spots of purple or traces of green on interambulacral midline; ambulacra purple, sometimes with white midline; pore zones more greenish brown; apical system purple green, the genital plates much darker than ocular plates. Primary spines distinctly banded in red and white, ground color of collar basally purple becoming green, with series of elongated white spots, more conspicuous on the upper side than on the lower side. Distribution: Prionocidaris glandulosa is reported from the Malayan Archipelago and the Philippines. Bathymetric range about 50 to 140 m. Prionocidaris hawaiiensis A. Agassiz & H. L. Clark, 1907 (Fig. 4.23 C) Test: Low, flattened above and below; maximum recorded test diameter 41 mm. Apical system: Circa 45 % of test diameter; ocular and genital plates very low and broad, forming a narrow monocyclic circle, densely set with small tubercles, slightly larger ones cover the periproctal plates. Ambulacra: Marginal tubercles and inner series of tubercles regular, sometimes additional tubercles in the midzone. Interambulacra: Areoles not depressed, scrobicular circle not prominent. Peristome: Subpentagonal, about same size as apical disc. Primary spines: In length, 2–2.5 times the test diameter, tapering to a blunt point, set with series of more or less coarse thorns; collar about 4 mm, gradually tapering; oral primaries flattened and with long collar and short, cap-like shaft.

▸ Fig. 4.23: (A, B) Prionocidaris glandulosa. (A) Aboral side with some spines, diameter of test 16 mm; south of Flores, Indonesia. ZMUC. (B) Side view. (C) Prionocidaris hawaiiensis. Side view with spines, diameter of test about 28 mm; Molokai, Hawaii. ZMUC ECH 165. (D, E) Prionocidaris pistillaris. (D) Close-up of oral and lateral spines, diameter of test about 42 mm; Mauritius. ZMUC. The primary spines are set with fine granules. (E) Large specimen with spines, diameter of test about 61 mm; Dar es Salaam, Tanzania. The primary spines are incrusted, only the lilac bases remain bare. (F) Prionocidaris thomasi. Side view with some remaining with spines, diameter of test about 65 mm; Hawaii. Photo from A. Agassiz & H. L. Clark (1907).

4.1.1 Order: Cidaroida Claus, 1880 



A

C

B

D E

F

 57

58 

 4.1 Subclass Cidaroidea Smith, 1984

Secondary spines: Scrobiculars rather long, about 7 mm, very slender and pointed, not appressed; marginal spines of same length, but even more slender; spines of ocular and genital plates short. Color: The cleaned test is white with a more or less distinct reddish tint, the ambulacra are intensely red to orange. The primary spines are usually banded in brick red and white, the green yellow collar being set with white spots. The secondary spines have a more green brown color. Distribution: This species is recorded only from Hawaii at depths of 32 to 510 m. Prionocidaris pistillaris Lamarck, 1816 (Fig. 4.23 D, E) Main features like genus. Test: Diameter may reach about 70  mm. The primary spines are very typical in being closely set with small granules of uniform size, sometimes laterally enlarged, distally with ridges forming a crown at the tip. Spines: Dark with white granules; the collar with very conspicuous alternating stripes of purple and white; the secondaries are dark purplish brown to lilac; the bare test is green. Distribution: Found at Mauritius, Seychelles, Madagascar, and East Africa from Dar es Salaam to Natal; living from the littoral to a depth of 60 m. Prionocidaris popiae Hoggett & Rowe, 1986 Test: Diameter may reach 46 mm. Apical system: With widely insert ocular plates; inner areas of genital and ocular plates appearing rather bare, due to the small size of tubercles, those on periproctal plates distinctly larger. Ambulacra: Interporiferous zone with regular marginal tubercles and much smaller inner tubercles on the median zone, which thus appear rather naked. Interambulacra: 7–8 plates per column; median zone half the width of areoles. Primary spines: In length, 2–2.5 times the diameter of test, thickened above the collar, shaft with irregular thorns, becoming serially arranged to ridges distally, lateral serrated edges distinct. Scrobicular spines: About 7  mm long, flattened, tapering to a round tip; small spines very short, scale-like and appressed. Color: Test creamy white with marginal tubercles in deep purple; scrobicular tubercles with distinct pink tint; primary spines banded in dark brown purple to paler red; collar and neck of primary spines set with white to green spots on a red brown ground, distal shaft with deep red thorns; scrobicular spines deep purple basally, with an abrupt transition to bright grass green distally; marginal spines deep purple.

Distribution: The species is restricted to New Caledonia and Vanuatu at 55 to 275 m. Remarks: Prionocidaris popiae lives sympatrically with Prionocidaris callista. It differs by the dark color of the apical plates and ambulacra, being purple in the former and green brown with bright red secondary spines in the latter. Additionally, the areoles of P. popiae are more transverse oval, and the primary spines are longer. Prionocidaris thomasi A. Agassiz & H. L. Clark, 1907 (Fig. 4.23 F) This species differs markedly from Prionocidaris ­hawaiiensis, also endemic to the Hawaiian islands, in having round, well-separated areoles. In P. hawaiiensis, the areoles are transversely oval and mostly confluent. In life, all secondary spines are dark in contrast to the light primary spines. Genus Stylocidaris Mortensen, 1909 The genus is characterized by more or less slender primary spines tapering to a rather fine point. Usually, the areoles are round and well separated. The globiferous pedicellariae lack an end tooth the opening being terminal. Test: Moderately thick. Apical system: Ocular plates usually insert; genital plates of same size, gonopores small, located close to the outer edge. Ambulacra: Pore pairs not conjugate; interporiferous zone with regular series of contiguous marginal tubercles and smaller inner series. Interambulacra: 6–7 plates per column; areoles circular and only slightly depressed, widely separated; scrobicular tubercles only slightly differentiated; sutures faintly incised. Peristome: Usually smaller than apical disc, may be ­protruding. Globiferous pedicellariae: Without end tooth. Primary spines: Slightly fusiform, tapering to the tip; more or less slender; collar and neck short; shaft set with thorns or granules. The key in Mortensen (1928) distinguishes the numerous species mainly by the colors of test and spines. It is often difficult to delimitate them clearly. Stylocidaris affinis Philippi, 1845. Atlantic, Caribbean, and Mediterranean. Stylocidaris albidens H. L. Clark, 1925. Indian Ocean; deeper water. Stylocidaris amboinae Mortensen, 1928. Indo-West Pacific. Stylocidaris annulosa Mortensen, 1927. Philippines, deeper water. Stylocidaris badia H. L. Clark, 1925. Mauritius, deeper water.



Stylocidaris bracteata A. Agassiz, 1879. Indo-West Pacific. Stylocidaris brevicollis de Meijere, 1904. Indo-West Pacific. Stylocidaris calacantha A. Agassiz & H. L. Clark, 1907. Hawaii. Stylocidaris cingulata Mortensen, 1932. Indian Ocean. Stylocidaris conferta H. L. Clark, 1916. Australia. Stylocidaris effluens Mortensen, 1927. Philippines, deeper water. Stylocidaris fusispina Mortensen, 1928. Japan. Stylocidaris laevigata Mortensen, 1939. Gulf of Aden. Stylocidaris lineata Mortensen, 1910. Caribbean. Stylocidaris lorioli Koehler, 1927. Indian Ocean. Stylocidaris maculosa Mortensen, 1928. Northwest Pacific. Stylocidaris reini Döderlein, 1887. Indo-West Pacific. Stylocidaris rufa Mortensen, 1928. Hawaii. Stylocidaris ryukyuensis Shigei, 1975. East China Sea. Stylocidaris tiara Anderson, 1894. Indian Ocean. Literature: H. L. Clark 1909, 1925, 1946; Döderlein 1885, 1887; de Meijere 1904; Mortensen 1910, 1927, 1928, 1932, 1939; Phelan 1970; Shigei 1975, 1986; Rowe & Hoggett 1986; Rowe & Gates 1995. Stylocidaris affinis Philippi, 1845 (Fig. 4.24 A–C) Test: Diameter up to 48 mm. Apical system: About half the diameter of test; all plates densely covered by small tubercles of uniform size; sometimes naked edges. Ambulacra: Sinuate; marginal series of tubercles very regular, one or two series of inner tubercles; leaving a distinctly naked, but usually not sunken median band. Interambulacra: Scrobicular tubercles not very prominent; smaller tubercles decreasing slightly in size toward the median area, occasionally forming a narrow, naked median suture. Primary spines: Length about 1 to 1.5 the diameter of test, slender, slightly widened at the base, tapering gently to the distal, blunt end; shaft with granulated ridges. Secondary spines: Scrobiculars about 4 mm long, flattened, and narrow, tapering slightly to the rather straightcut tip; marginal spines of same general shape, half length of scrobicular ones; small spines slender. Color: The primary spines are white with more or less conspicuous brown bands, collar often pink or red. The secondary spines are brick red or with a red midline; the red color may sometimes be very faint. The bare test is usually white or light cream with more or less green; ambulacral midline and interambulacral sutures brown. The apical system is somewhat darker; generally, a still darker, ringshaped band is running across the genital plates.

4.1.1 Order: Cidaroida Claus, 1880 

 59

Distribution: Stylocidaris affinis is known from the Mediterranean, the Middle Atlantic from off Madeira and the Canaries down to Cape Verde, and all over the West Indies from the Bermudas to Barbados at depths of 30 to 1,000 m. Stylocidaris albidens H. L. Clark, 1925 (Fig. 4.24 D–F) Test: Flattened above and below; maximum reported diameter of test 40 mm. Apical system: About 45 % of test diameter, usually faintly raised. Ambulacra: Marginal tubercles contiguous, small tubercles heterogeneous. Interambulacra: Uppermost tubercles slightly crenulated; extrascrobicular tubercles decreasing in size toward the slightly incised median suture, present also along the outer side of the plates. Primary spines: Slightly widened above the base (fusiform), then tapering gently to the blunt or crown-like tip; collar and neck short, shaft set with 10 to 12 series of sharp thorns, becoming serrated ribs distally; oral primaries simple, more or less set with furrows. Secondary spines: Scrobiculars about 4  mm in length, flattened with rounded point; marginal spines slender. Color: The general color is a dirty creamy yellowish, the naked test white with olive interporiferous zones and olive green apical plates; primary spines pink to brown, sometimes banded, with white thorns; collar with distinct red brown longitudinal lines; secondary spines with conspicuous green olive stripe changing into pink toward the base. Distribution: This species is recorded from the eastern Indian Ocean to the Philippines at deeper water. Stylocidaris amboinae Mortensen, 1928 (Fig. 4.25 A, B) Test: Strongly flattened above and below; height about half the diameter, which may reach 40 mm. Apical system: Plates densely tuberculated, larger ones around the gonopores. Ambulacra: Distinctly sinuate; pores relatively small; marginal tubercles regular, median space densely filled with comparatively large secondary tubercles. Interambulacra: Areoles well separated; scrobicular circle not very prominent; extrascrobicular space covered by smaller tubercles, gradually decreasing in size toward the median line; sutures distinct. Primary spines: In length, only 1–1.3 the diameter of test; rather thick, tapering only slightly with rather abruptly cut distal end; collar short, neck about twice the length of collar; shaft densely set with numerous small spinules, more or less arranged longitudinally; oral primaries simple and straight.

60 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

C

D

E

F

Fig. 4.24: (A–C) Stylocidaris affinis. (A) Aboral side of test, diameter 32 mm; Crete, Mediterranean. (B) Aboral side with spines, diameter of test 23 mm, longest spine 34 mm; Aegean Sea, Greece. (C) Close-up of median part of interambulacrum, test diameter 31 mm; Italy. Scale: 5 mm. (D, F) Stylocidaris albidens. (D) Aboral side with spines, diameter 22 mm; Siquijor, Philippines (photos by Bas van der Steld). (E) Side view with spines, diameter of test 20 mm; Andaman Islands. ZMUC. (F) Aboral side of test, diameter 23 mm; Siquijor, Philippines.

4.1.1 Order: Cidaroida Claus, 1880 



A

C

 61

B

D

Fig. 4.25: (A, B) Stylocidaris amboinae. (A) Aboral side with spines, test diameter 28 mm; Amboina Bay, Indonesia. ZMUC ECH 62. (B) Oral side. (C, D) Stylocidaris annulosa. (C) Aboral side with two remaining spines, diameter of test 28 mm, spine 61 mm; Philippines. ZMUC ECH 77. (D) Oral side.

Secondary spines: Almost rectangular, scrobicular spines 3–4 mm long, marginal spines of same shape, but smaller. Color: Test generally white, genital plates dark brown to green; primary spines pink, sometimes banded in white; secondary spines with a green brown to red brown median stripe.

Distribution: The species is reported from the Malayan region and the Philippines, 180 to 225 m. Stylocidaris annulosa Mortensen, 1928 (Fig. 4.25 C, D) Test: Sometimes gently vaulted above; maximum reported diameter 39 mm.

62 

 4.1 Subclass Cidaroidea Smith, 1984

Apical system: Barely half the test diameter in width; ocular plates widely exsert; periproct small. Ambulacra: Sinuate, marginal series regular, inner space with one small tubercle per plate, median area rather naked with sunken midline. Interambulacra: Areoles very large and flat, sometimes with radial striations; lowermost ones confluent and transverse oval; scrobicular tubercles prominent, extrascrobicular zone narrow, set with some few very small tubercles, leaving a distinct naked area. Peristome: Distinctly smaller than apical disc. Primary spines: In length, 2.5–3 times the diameter, slender, tapering to a fine tip; shaft set with 12 to 15 longitudinal series of low, rounded spinules, generally not forming ridges, collar about 3  mm long; oral primaries very slender and smooth. Secondary spines: Very slender and pointed, scrobiculars about 7  mm, marginal spines in ambulacra 4 mm long. Color: Naked test white, upper side darker, genital and periproctal plates green brown, oculars white; series of marginal tubercles distinctly green brown. Primary spines with numerous narrow red and broader green white bands, paler on the lower side of the spine; secondary spines white with a more or less conspicuous green brown median stripe. Distribution: Reported from the Philippines from deeper water. Stylocidaris badia H. L. Clark, 1925 (Fig. 4.26 A, B) Test: Rather high; slightly flattened above; diameter of test may reach 38 mm. Apical system: About half the diameter of test; ocular plates insert; periproctal plates elevated with a tuft of larger spines. Ambulacra: Interporiferous zone more than twice the width of pore zone; marginal tubercles contiguous, inner space set with smaller tubercles more or less in series. Interambulacra: Areoles well separated, some of the upper tubercles slightly crenulated; median space half the width of areoles, set with small tubercles, leaving a naked, more or less sunken median line. Peristome: Approximately as large as apical disc. Primary spines: Above the ambitus very long, 3 times the diameter of test, somewhat thickened basally, tapering to a sometimes flaring point; closely set with thorns of uniform size, about 1.5 mm long, arranged in about 10 regular series; thorns lancet-shaped, slightly transparent, sometimes bifurcating at the tip, erect and separated, not rising from a ridge; distally the thorns decrease in size, uniting to ridges toward the point; collar short; oral ­primaries slightly flattened and simple.

Secondary spines: Scrobiculars about 4.5 mm long, flat, not pointed, appressed; marginal spines of same shape, but only 2.5 mm long. Color: In life, test and secondary spines uniformly red to brown, apical plates red; marginal tubercles brown; primary spines banded in red brown and white, at least in the distal part; collar uniformly red brown. Distribution: Reported from the Indian Ocean at deeper water. Stylocidaris bracteata A. Agassiz, 1879 (Fig. 4.26 C, D) Test: Flattened above, less so below. Apical system: Larger tubercles on inner and outer edge of genital plates, inner ones markedly elongated. Ambulacra: Marginal tubercles regular, secondary tubercles in younger specimens forming also a regular row; in larger specimens, this row is obscured by a second small tubercle per plate, above the other; additionally, there are small tubercles. Interambulacra: Areoles widely separated, below the ambitus transverse oval, lowermost confluent; midline marked; small pits at the median end of the horizontal sutures. Peristome: Distinctly smaller than apical disc, slightly elevated. Primary spines: In length, 1.5 to 2.5 the test diameter, slightly widened basally, tapering gently to the point; shaft set with ten sharply serrated ridges, more developed on the upper side; collar about 1 mm, smooth neck about 2 mm long and shining; oral primaries with longitudinal ridges. Secondary spines: All of them nearly rectangular, scrobiculars 3–4 mm long, the other smaller; apical secondary spines short and fine, larger ones form a tuft over the anal opening and an outer fringe. Color: General color creamy with faint pink, median area of ambulacra dark brown; apical plates in the whole olivepurple or only with not well-limited darker spots; primary spines green yellow with red brown bands, or sometimes with dark irregular small patches; continuing over neck and collar as a series of small spots; secondary spines light pink, usually without median stripe. Distribution: This species is recorded from Japan through the Philippines and the Malayan Archipelago to Fremantle at the west coast of Australia. Bathymetric range 27 to 71 m. Remark: Shigei (1986) synonymized S. bracteata with S. maculosa. Stylocidaris brevicollis de Meijere, 1904 (Fig. 4.27 C) Test: Rather high, not flattened above and below; largest recorded test diameter 40 mm.

4.1.1 Order: Cidaroida Claus, 1880 



A

 63

B

C

D

Fig. 4.26: (A, B) Stylocidaris badia. (A) Aboral side of test, diameter 45 mm; Mauritius. (B) Aboral side with spines, test diameter 16 mm, spines up to 63 mm; Mauritius. ZMUC. (C, D) Stylocidaris bracteata. (C) Aboral side of test, diameter 24 mm; Amboina, Indonesia. ZMUC. (D) Aboral side with spines, diameter of test 25 mm; Indonesia.

Apical system: Slightly raised, oculars insert; all plates densely covered in small tubercles, on outer edge of genital plates slightly enlarged. Ambulacra: Marginal tubercles regular, inner space of plate filled with a few small tubercles. Interambulacra: Areoles small, well separated, transverse oval except the uppermost ones; scrobicular tubercles prominent; extrascrobicular area well tuberculated. Primary spines: In length, 1.5–2 times the test diameter; shaft slightly fusiform, set with low thorns arranged in

about 12–14 series, becoming ridges distally; on upper side of spines more developed than below; neck smooth, collar very short, not more than 0.5 mm long; oral primaries with ridges; scrobicular spines 3–3.5 mm long, chisel-shaped; secondary spines on the whole rather erect. Color: Usually, the naked test is white on the interambulacra, the interporiferous zones in the ambulacra are red, even down to the peristome. But there occur also specimens with much more red, e.g. as spots in the areoles. The primary spines have a red purple tint with conspicuously white thorns, the secondaries are light red or pink, those

64 

 4.1 Subclass Cidaroidea Smith, 1984

A

C

B

D

Fig. 4.27: (A, B) Stylocidaris brevicollis. (A) Aboral side, diameter with spines 136 mm; Norfolk Ridge, Tasman Sea, Australia (photo by Willi Clarenbach). (B) Side view of test, diameter 36 mm; south of Norfolk Ridge, Tasman Sea. (C) Stylocidaris calacantha. Side view with spines, diameter of test 31 mm; Hawaii. ZMUC. (D) Stylocidaris cingulata. Side view with some remaining spines. Diameter of test 22 mm; Indian Ocean. ZMUC ECH 106. The test is almost spherical.

of the ambulacra darker. The darker color continues as longitudinal stripes over the neck and the short collar down to the milled ring. Distribution: Indo-Malayan Archipelago to eastern Australia including Tasman Sea and Norfolk Island. ­ Bathymetric range 69 to 301 m. Stylocidaris calacantha A. Agassiz & H. L. Clark, 1907 (Fig. 4.27 C) Test: Low, flattened above and below; largest recorded test diameter 42 mm. Apical system: In width, about half the test diameter; tubercles on inner edge of genital plates elongated. Ambulacra: Regular series of marginal and smaller secondary tubercles. Interambulacra: Scrobicular tubercles more than twice as large as marginal tubercles, median space in width one third of areole.

Primary spines: Thickened base or slender, shaft with small tubercles or granules, arranged in dense, low ridges; shining neck about 2 mm, collar 1 mm long; oral primaries ridged. Scrobicular spines: About 4  mm long, slightly tapering toward the round end. Color: In general, very pale brown with green apical disc, genital plates deeper green than oculars; secondary spines with deep green median stripe. Distribution: This species is known only from the ­Hawaiian Islands at a depth of 225 to 355 m. Stylocidaris cingulata Mortensen, 1932 (Fig. 4.27 D) Apical system: Conspicuously raised, set with only a few tubercles concentrated along the outer and inner edges; ocular plates broadly insert. Ambulacra: Interporiferous zone of same width as pore zone; marginal tubercles nearly contiguous, irregular row



of inner tubercles, median line slightly sunken; pores rather distant, usually the outer pore larger. Interambulacrum: Areoles widely separated, even the lowermost not confluent; scrobicular tubercles not very prominent, circle may be open at the adapical edge; extrascrobicular median space narrow, only a single circle of secondaries alternating to scrobiculars. Peristome: Slightly raised, as large as apical disc. Primary spines: Up to twice the length of test diameter, collar about 1 mm long, neck shining; shaft set by minute ridges; oral primaries with distinct ridges. Scrobicular spines: About 3–4 mm long, simple, marginals scarcely half that size. Color: Denuded test white with light greenish tint, genital and periproctal plates darker and more olive green; primary spines with numerous, conspicuously red bands on white ground; secondary spines with narrow olive green stripe. Distribution: The holotype came most probably from the Indian Ocean. Stylocidaris conferta H. L. Clark, 1916 (Fig. 4.28 A, B) Test: Thin and fragile; maximum recorded diameter 43 mm. Apical plates: Scarcely tuberculated, more or less elevated. Ambulacral midline: Slightly sunken. Interambulacral: Areoles small, sutures incised. Peristome: Smaller than apical disc, more or less flat. Primary spines: Slender, usually tapering abruptly near the distal end; shaft very densely set with low, rounded knobs of uniform size, not arranged in series; neck smooth and shining; oral primaries lancet-shaped and smooth. Secondary spines: Scrobiculars slender and ca. 5  mm long; marginal spines very slender and nearly as long as scrobiculars. Color: Test and spines in general white with more or less distinct green brown spots on genital plates or on ambulacra and/or interambulacral median sutures; primary spines with 2–3 narrow red bands, but may be lacking; secondary spines with an indistinct stripe in red brown or olive. Distribution: The species is restricted to the east coast of Australia from Queensland to Tasmania and off New ­Caledonia. Depth range 135 to 550 m. Stylocidaris effluens Mortensen, 1927 (Fig. 4.28 C, D) Test: Slightly elevated above, flattened below; maximum recorded diameter of test 42 mm. Apical system: About half the diameter of test, inner plates raised; ocular plates more or less broadly insert. Ambulacra: Marginal tubercles in regular series, two or more irregular inner tubercles, only sometimes leaving a

4.1.1 Order: Cidaroida Claus, 1880 

 65

naked median space (there is much variation); pore zones not sunken. Interambulacra: 6–7 plates per column; areoles shallow, widely separated; the uppermost tubercles (and spines) of a circle rudimentary; the ring widening irregularly on the adapical side, or even being open; extrascrobicular area narrow, set with very small tubercles, leaving a more or less distinct naked median line. Peristome: Slightly smaller than apical disc, quite flat. Primary spines: Very slender, in length about 1 to 1.5 times the diameter of test, sometimes more; tapering gradually to a blunt point; set with 9–10 rather coarsely serrated ridges; collar short; oral primaries very slender, straight, smooth, or very finely serrated. Scrobicular spines: About 4 mm long, concave distally; marginal spines more slender. Color: Primary spines white with numerous, more or less distinct narrow bands in light brown; secondary spines with red or green median stripe; denuded test white with more or less deep green on genital and periproctal plates; marginal tubercles also greenish. Distribution: Around the Philippines at deeper water. Stylocidaris fusispina Mortensen, 1928 Mortensen (1928) doubted whether this species belongs to the genus Stylocidaris based on the unusual obliquely positioned pore pairs. Ikeda (1941) made it a genus of its own, Chorocidaris. Test: Small and low; maximum recorded test diameter 13 mm. Apical system: Relatively large and raised; ocular plates exsert; plates on the whole rather bare, except irregular rows along the inner and outer edge of genital and ocular plates. Ambulacra: Narrow; marginal tubercles prominent and confluent, inner area naked or set with only a single very small tubercle; pore pairs subconjugate and unusually oblique. Interambulacra: Areoles flat, narrowly separated; scrobicular circle not prominent. Peristome: Smaller than apical disc. Primary spines: Short, in length less than diameter of test, basally more or less conspicuously thickened; collar very short; shaft set with sharp, smooth longitudinal ridges with shiny interspaces, in the basal part transformed into rows of 8–10 rounded granules; tip simple; oral primaries with distinct ribs. ­S econdary spines: Flattened, slightly tapering to the rounded point. Color: Denuded test white, some tubercles having a pink tint, the apical plates are red yellow; primary spines with

66 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

D

Fig. 4.28: (A, B) Stylocidaris conferta. (A) Side view of test, diameter 26 mm; Huon Island, New Caledonia. (B) Primary spines of a specimen of 32 mm in diameter; Port Jackson, New South Wales, Australia. ZMUC. The longest spine measures 55 mm. (C, D) Stylocidaris effluens. (C) Aboral side of test, diameter 27 mm; Siquijor, Philippines. The rings of scrobicular tubercles on the uppermost plates are longitudinally elongated or open toward the apical disc. (D) Side view.

three or four distinct red yellow bands on yellow ground; secondaries uniformly red yellow or with more or less ­distinct darker stripe.

Distribution: The species is confined to southern Japan from Sagami Bay to the Ryu-Kyu-Islands. Bathymetric range ~100 to 400 m.



Literature: Ikeda 1941; Mortensen 1928; Shigei 1981, 1986. Stylocidaris laevispina Mortensen, 1939 (Fig. 4.29 A) Test: Low; Mortensen reported a test diameter of 37 mm. Apical system: Tubercles sparse, may be distinctly comma-shaped along inner edge of genital plates. Ambulacra: Interporiferous zone as broad as poriferous zone; marginal series of tubercles regular, not contiguous; single inner tubercle forming a parallel row to marginal one. Interambulacra: Areoles well separated; scrobicular tubercles not much differentiated, median space half the width of an areole, no naked median line. Primary spines: In length, from the same as diameter to more than twice the diameter; shaft may be slightly fusiform or cylindrical, tapering to a point; surface of shaft set with about 15 low, indistinctly serrated ridges, oral primaries finely ridged with smooth edges, slightly widened. Secondary spines: Scrobiculars about 4  mm long, almost rectangular, not much appressed; marginal spines more slender, about 3 mm long, smaller spines erect and pointed. Color: The test with the spines is creamy, the apical system dark brown continuing along the ambulacral midline and interambulacral sutures; denuded test white with green tinge on the upper interambulacra and interporiferous zone in ambulacra; genital plates dark olive in contrast to white ocular plates; primary spines faintly pink, sometimes with a darker ring between collar and neck; secondary spines white with an indication of a darker midline. Distribution: Mortensen (1939) described this species from off Cape Gardafui at the Gulf of Aden at a depth of 73 to 200 m. Stylocidaris lineata Mortensen, 1910 (Fig. 4.29 B) Test: Flattened above and below. Apical system: With an almost naked, red ring lacking small granules; the tubercles on both sides of this circle being radially elongated. Ambulacra: Moderately sinuous; marginal tubercles in regular series, usually only one inner tubercle. Interambulacra: Areoles large, well separated down to the lowermost ones; scrobicular circle inconspicuous, median zone naked. Primary spines: In length, 1.5–2 times the diameter of test, slender, tapering to the tip; neck short; shaft set with numerous rows of small thorns; oral primaries with distal ribs. Secondary spines: Scrobiculars relatively broad, slightly tapering to a blunt or cut end; marginal spines more slender and pointed.

4.1.1 Order: Cidaroida Claus, 1880 

 67

Color: The general color is a light brown with a conspicuous red brown circle on the apical disc, the sutures marked as red brown lines; scrobicular and marginal spines are light brown without stripe. Distribution: This species is restricted to the West Atlantic at depths of 100 to 500 m. Biology: This species is reported to form dense clusters of several individuals for more effective spawning (D. L. Pawson, personal communication). Differentiation: It is almost impossible to distinguish this species from Stylocidaris affinis by the naked test. Their geographic range overlaps in the west Atlantic, where they often live sympatrically in the same habitat. Typically, the two species differ by the following features: Stylocidaris lineata has an apical system with a naked, reddish ring lacking small granules; the tubercles on both sides of this circle are radially elongated. Stylocidaris affinis: has a darker, not well-limited ring that is not naked. The tubercles are round being scattered over the apical disc. Scrobicular and marginal spines in S. lineata are white without a conspicuous reddish median stripe as in the case of S. affinis. Remark: Mironov (2006) regards Stylocidaris affinis synonymous with S. lineata. He examined the populations from the Mediterranean through the islands and seamounts in the northeast Atlantic to the coasts of North and South America and the Caribbean. With this material in hand. he declared that there is a gradual change from the typical S. affinis in the east toward a typical S. lineata in the west. All intermediates occurred, so that it is impossible to separate them clearly. The two species are both of considerable variation often precluding a clear delimitation. Stylocidaris lorioli Koehler, 1927 (Fig. 4.29 C, D) Test: Flattened below, raised above. Apical system: Nearly half the test diameter; all ocular plates broadly insert; genital plates rather high. Ambulacra: In width about 45 % of interambulacra, interporiferous zone broad, marginal tubercles in regular rows, two inner tubercles. Interambulacra: Well-separated areoles, slightly sunken. Primary spines: 12 series of granules, becoming ridges at about half the distance to the top. Scrobicular spines: Slightly tapering; marginal spines of nearly the same length, but more slender. Color: In general, test and spines are light brown, the apical system dark green or olive, this color continuing toward the upper interambulacra. Sometimes, there are faint red bands on the primary spines. Distribution: This species is recorded from the Andaman Islands. Depth 200 m.

68 

 4.1 Subclass Cidaroidea Smith, 1984

B

A

C

E

D

Fig. 4.29: (A) Stylocidaris laevispina. Close-up of aboral side with spines, diameter of test 35 mm; Cape Gardafui. ECH 196 ZMUC. (B) Stylocidaris lineata. Aboral side with some spines, test diameter 30 mm; off Grenada. ZMUC. There is a dark ring on the apical plates. (C, D) Stylocidaris lorioli. (C) Side view of denuded part of test, diameter 24 mm; off Port Blair, Andaman Islands. ZMUC. The sea urchin was hurt in the ambulacra. (D) Aboral side, partly with spines. (E) Stylocidaris maculosa. Aboral side with spines, diameter of test 11 mm; Bonin Islands, Japan. ZMUC. The spines are narrowly banded.



Stylocidaris maculosa Mortensen, 1928 (Fig. 4.29 E) Test: Rather low, small form. Apical system: Densely covered by conspicuously small secondary spines. Primary spines: Coarsely serrated, especially laterally, giving the shaft a flattened appearance; secondary spines relatively broad, not rod-shaped. Color: Test and secondary spines are brown, the primary spines are banded in brown purple and white, with the brown continuing as patches toward the collar. Remark: M. Shigei (1986) synonymized this species to Stylocidaris bracteata. However, Mortensen (1928) rejected the synonymization because the two species differ in their spots on the collar: S. maculosa has a single brown spot, whereas S. bracteata has some small red spots. Furthermore, S. maculosa seems to be a small form, while S. bracteata reaches more than the double diameter. Stylocidaris reini Döderlein, 1887 (Fig. 4.30 A, B) Test: Low, test diameter may reach 49 mm. Apical system: About half the test diameter in width, sometimes slightly elevated; ocular plates narrowly insert; densely tuberculated, along outer and inner edge of genital plates enlarged or elongated, inner edge may sometimes be naked. Ambulacra: Sinuate; marginal tubercles small and very regular; inner space set with one or more small tubercles. Interambulacra: Areoles relatively deep, well separated, scrobicular circles conspicuous, tubercles about twice the size of marginal tubercles; extrascrobicular tubercles gradually decreasing in size toward the median and the outer suture, median line distinct, but usually not naked. Peristome: Distinctly smaller than apical disc. Primary spines: Slender; in length, 1.5 to 2 of diameter of test, tapering gently to a rounded point; collar about 2 mm long, neck of same length, smooth and shiny; shaft set with regularly arranged spinules of uniform size, distally becoming ridges; spinules may be rather thorny; oral primaries slender and usually ridged. Secondary spines: Scrobiculars about 4–5 mm, tapering to a round point; marginal spines of same shape, but half the length. Color: In general, test and spines are white. The apical system is usually darker in red brown to green brown or dark purple, the color often confined to the genital plates. The primary spines show not well-limited bands of light pink, or they are uniformly whitish or greenish. The denuded test is white, only the genital plates are of

4.1.1 Order: Cidaroida Claus, 1880 

 69

a more or less conspicuous red brown to green olive. The ­secondary spines have a more or less distinct median stripe of red or green. The specimens from the Norfolk Ridge have primary spines distinctly banded in green and red and pale apical plates. The denuded test shows a green tint. Distribution: Indo-West Pacific from Sagami Bay, Japan, through the Philippines and the Malayan Archipelago to Australia from Queensland to southeast New South Wales; New Guinea, New Britain, and Norfolk Ridge, and northern Tasman Sea. Depth 100 to 841 m. Stylocidaris rufa Mortensen, 1928 (Fig. 4.30 C, D) Test: Diameter may reach 41 mm. Ambulacra: With regular series of marginal tubercles, single inner tubercle per plate in regular rows, median space naked. Interambulacra: Areoles shallow; scrobicular tubercles twice the size of marginal tubercles; extrascrobicular tubercles closely set. Primary spines: Slightly fusiform; shaft covered by spinules arranged in more or less distinct ridges, basically resembling warts, becoming sharp ribs toward the tip. Scrobicular spines: 4 mm long, flat, point rounded; marginal spines slender, 2 mm long. Color: Primary spines light red brown with conspicuously white spinules, collar red brown; scrobicular spines purple brown; marginal spines yellowish, forming distinct radiating light lines; denuded test light green red with dark red brown genital and periproctal plates. Distribution: Known only off the Hawaiian Islands at depths of 128 to 515 m. Stylocidaris ryukyuensis Shigei, 1975 (Fig. 4.31 A–C) This species is characterized by its conspicuously chocolate-colored scrobicular spines. Test: Flattened above and below; medium sized. Apical system: Ocular plates exsert; genital pores small; all plates covered by small tubercles of uniform size; they are larger and elongated along the inner edge of both the genital and ocular plates. Ambulacra: Interporiferous zone twice the width of pore zone; marginal tubercles contiguous forming regular series; inner space set with two smaller tubercles per plate one above the other arranged in regular series; there are also a few minute tubercles, no naked median area; pores of a pair rather distant of each other. Interambulacra: Areoles rather shallow, separated except for the two lowermost ones; scrobicular tubercles

70 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

D

C

Fig. 4.30: (A, B) Stylocidaris reini. (A) Aboral side with spines, diameter of test 28 mm; Philippines. ZMUC. (B) Aboral side of test, diameter 36 mm; Kyushu, Japan. ZMUC. (C, D) Stylocidaris rufa. (C) Aboral side, partly with spines, diameter 32 mm; Hawaii. ZMUC ECH 284. (D) Side view of denuded part of test.

­differentiated, but the ring is not markedly raised; extrascrobicular space two thirds of the width of an areole; plates densely set by smaller tubercles decreasing in size toward the edges of the plates, midline scarcely sunken, not naked.

Peristome: Distinctly smaller than apical system, about 28 % of test diameter. Primary spines: Slightly fusiform, tapering to a small crown; shaft set with ten series of sharp thorns; oral primaries short without thorns.

▸ Fig. 4.31: (A–C) Stylocidaris ryukyuensis. (A) Aboral side with spines, test diameter 32 mm; off Taiwan. The secondary spines are

conspicuously chocolate brown. (B) Oral side with spines. (C) Aboral side of test, diameter 40 mm; Taiwan (photo by W. Clarenbach). (D–F) Stylocidaris tiara. (D) Side view of test, diameter 27 mm; Ceylon. ZMUC. (E) Side view of highly an inflated test, diameter 34 mm; Ceylon. ZMUC. The upper side may be more or less devoid of areoles, tubercles, and primary spines. (F) Side view with remaining spines, test diameter 34 mm; Travancore coast, Ceylon. ZMUC. The primary spines are very brittle and mostly broken.

4.1.1 Order: Cidaroida Claus, 1880 



A

C

E

B

D

F

 71

72 

 4.1 Subclass Cidaroidea Smith, 1984

Secondary spines: Scrobiculars 3 mm long, flattened or convex and with truncated end, finely ridged; marginal spines scarcely more slender. Color: Scrobicular spines dark chocolate brown; other secondary spines pale yellowish brown; primary spines green gray with a striped or spotted basal part; the collar is whitish. The denuded test is white with more or less darker primary tubercles, the apical system is a faint purplish brown. Distribution: Shigei (1975) described this species only from the East China Sea off the southern Ryukyu Islands. Meanwhile, it is recorded also from the Taiwan Strait. Bathymetric range 100 to 200 m. Stylocidaris tiara Anderson, 1894 (Fig. 4.31 D–F) This species is very typical in its general shape and in the appearance of its primary spines. Test: Maximum recorded test diameter 42 mm. Lower side flattened; upper side raised; uppermost tubercles rudimentary to a various degree, the scrobicular circle being somewhat outdrawn; usually more conspicuous in larger specimens. Apical system: Pentagonal; periproctal plates strongly elevated. Primary spines: Very brittle, preserved only very rarely; set with about eight prominent, smooth ridges, not at all serrated or granuled. Color: In life, the specimen is chestnut brown with a green apical system; primary spines pale pink, toward the tip becoming light olive green; secondaries olive green with darker median stripe. The denuded test is whitish with green genital plates. Distribution: This species is restricted to the Indian Ocean, from Ceylon to the Andaman Islands. Bathymetric range 215 to 720 m. Genus Tretocidaris Mortensen, 1903 Test: Relatively solid, flattened above and below. Apical system: Subpentagonal; madreporite not enlarged; ocular plates usually insert; plates set with dense, uniform tubercles. Ambulacra: Interporiferous zone slightly broader than a single pore; pore pairs subconjugate; small marginal tubercles in regular series, inner zone with a single much smaller one per plate, naked median zone broad. Interambulacra: Up to 10 plates per column; primary tubercles, sometimes with traces of crenulation adapically; areoles circular and depressed, transverse oval below the ambitus; separated except the lowermost plates; scrobicular tubercles strongly differentiated; extrascrobicular areas narrow, sparsely set with small ­ tubercles; sutures incised.

Peristome: Slightly smaller than apical disc; interambulacral plates just extending to the mouth. Primary spines: Slender, long, cylindrical, or slightly tapering to the tip, collar and neck short; shaft set with more or less fine thorns arranged in rows, more developed at the upper side of the spines than on the underside; oral primaries not serrated. Secondary spines: Appressed. Distribution: The genus is restricted to the Atlantic. Remark: Tretocidaris is closely related to Stylocidaris and Hesperocidaris. In test morphology, both genera are very similar, but they differ considerably in the shape of the large globiferous pedicellariae. In Tretocidaris, the blade has a large end tooth and a tiny opening; in Stylocidaris, an end tooth is lacking and the opening is terminal. Two species are included in this genus: Tretocidaris bartletti A. Agassiz, 1880. Caribbean. Tretocidaris spinosa Mortensen, 1903. South Atlantic, St. Helena. Tretocidaris bartletti A. Agassiz, 1880 (Fig. 4.32 A, B) Test: Diameter may reach 67 mm. Color: Aboral side in general fawn colored to red brown, even deep red on the apical system with white borders along the ocular plates; sutures and ambulacral midline white, primary spines conspicuously banded in brown on either white or light green ground; scrobicular spines with brown greenish median stripe. Distribution: West Indies and Caribbean Sea at depths of 140 to 625 m. Remark: This species differs from Tretocidaris spinosa in the color of the secondary spines. In Tretocidaris bartletti, they are white or in a faint green; in T. spinosa, they are red brown. Tretocidaris spinosa Mortensen, 1903 (Fig. 4.32 C, D) Test: In outline, round to subpentagonal; maximum reported diameter of test 57 mm. Ambulacra: In width, scarcely 25 % of interambulacra; naked median band. Interambulacra: Only 12–14 scrobicular tubercles in a circle, widely spaced. Primary spines: Cylindrical or tapering to a crown or flaring tip; shaft set with ca. 15 series of spinules or more or less coarse thorns; oral primaries simple, flattened with square cut end. Secondary spines: Scrobiculars about 6  mm long, with straight-cut, slightly concave end; marginal spines about half the length of scrobiculars, very slender and pointed, as also the other secondaries.

4.1.1 Order: Cidaroida Claus, 1880 



A

 73

B

D

C

Fig. 4.32: (A, B) Tretocidaris bartletti. (A) Aboral side of young specimen with remaining spines. Diameter of test 18 mm; West Indies. ZMUC. (B) Oral side. (C, D) Tretocidaris spinosa. (C) Side view of test, diameter 42 mm; off St. Helena, southern Atlantic. ZMUC. (D) Aboral side with spines, diameter of test 30 mm; off St. Helena, South Atlantic. ZMUC.

Color: Primary spines light red brown with 5–6 more or less dark bands, series of white thorns continuing as white lines over the purplish red neck and pale reddish collar as white longitudinal lines; secondary spines red brown, darker toward the point; denuded test light yellow brown, sometimes with red genital plates; marginal tubercles also yellow brown; pore zones and sutures white. Distribution: Reported only from St. Helena and Ascension in the South Atlantic. Depth about 70 m.

Subfamily Ctenocidarinae Mortensen, 1928 This subfamily is characterized by its rather dense and uniform tuberculation on the interambulacra, usually lacking clearly differentiated scrobicular tubercles. The pore pairs are obliquely positioned. None of the globiferous forms of pedi­ cellariae show an end tooth, in contrast to the Goniocidarinae. The genera are largely confined to Antarctic and ­Subantarctic waters.

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 4.1 Subclass Cidaroidea Smith, 1984

Biology: It is very likely that all ctenocidarid species are brood-protecting their young, albeit not in all of them juveniles were found. The large gonopores of the female discharge large, yolk-rich eggs, which are fertilized in the open water. By means of spines and podia, the eggs are manipulated down the test of the mother to the peristomial membrane, where they are deposited on more or less depressed areas along the edge being covered by the oral spines. (In males, there may also occur a depressed peristome.) The young grow and develop directly to a juvenile sea urchin without passing through a larval stage or metamorphosis being nourished by the yolk in the egg. They start to feed independently when the mouth and the anus have opened. However, a juvenile can also survive when it is swept away before it has finished its development (M. Barker in Lockhart, unpublished thesis). The Antarctic cidarids (as many other Antarctic invertebrates) have a very slow development, and the reproductive cycle lasts more than a year. For most species, reproduction is aseasonal, but not continuous. The brood comprises a single cohort, all the young are of the same age. Lockhart et al. (1994) counted 535 brood juveniles on one specimen of Ctenocidaris sp. Remark: In contrast to the mode of brood-protecting in ctenocidarines and the species of Goniocidaris, the young of Austrocidaris canaliculata are kept sheltered on the depressed apical plates. This way, the species avoid the perilous transfer of the eggs from the apical system to the peristome. Five genera are included, restricted to Antarctic, ­Subantarctic, and Pacific deep waters: Aporocidaris A. Agassiz & H. L. Clark, 1907. Apical disc 60–75 % of test diameter. Ctenocidaris Mortensen, 1910. Scrobicular spines flattened, distinct from the other secondary spines, which are simple or more or less club-shaped. Homalocidaris Mortensen, 1928. Milled ring very broad forming a sort of platform around the base of the primary spine. Notocidaris Mortensen, 1909. Scrobicular and other secondary spines of the same shape, which may be simple, cylindrical, or club-shaped. Rhynchocidaris Mortensen, 1909. Scrobicular spines barely distinguishable from other secondaries in shape and length, all of them erect, giving the test a globular appearance. Most of the genera consist of rather numerous species. These may even increase in number by future research (Lockhart 2006, unpublished thesis). The large radiation is likely to be caused by the influence of the Antarctic Circumpolar Current. Literature: Koehler 1901; Mortensen 1909, 1910, 1928; Fell 1976, unpublished thesis; De Ridder et  al. 1992; Lockhart et al. 1994; Mooi et al. 2000; David et al. 2000, 2005; Pearse & Lockhart 2004; Lockhart 2006, unpublished thesis.

Genus Aporocidaris A. Agassiz & H. L. Clark, 1907 The genus is characterized by a very large, often conspicuously domed apical system and a naked and slightly sunken band along the interambulacral median suture. Test: More or less low, underside flat, plates rather thin and fragile. Apical system: Very large (65–75 % of test diameter), in larger specimens raised forming a dome or cone; ocular plates distinctly exsert, covered with tubercles; ocular pores encircled by a distinct rim; gonopores in females much larger than in males. Ambulacra: Narrow with relatively few plates; pore pairs closely set, may be coalesced, in distinctly oblique position; no naked median zone. Interambulacra: Areoles well separated, lower ones confluent; not sunken, median suture as a conspicuously naked and slightly depressed band; in larger specimens, extending into horizontal sutures; scrobicular tubercles hardly differentiated. Peristome: About half the test diameter, less than 10 ambulacral plates per column; edges often depressed forming marsupia. Primary spines: Long, very slender, and delicate in comparison to the other ctenocidarines; usually cylindrical ending in a simple point; collar short, neck conspicuous; shaft set with more or less regular series of small bumps or tiny thorns, the space between them covered with a more or less dense coat of simple cortical hairs. Secondary spines: Cylindrical and erect. There are six species, which are very similar. Aporocidaris antarctica Mortensen, 1909. Antarctic. Aporocidaris eltaniana Mooi et al., 2000. Antarctic. Aporocidaris fragilis A. Agassiz & H. L. Clark, 1907. North Pacific. Aporocidaris incerta Koehler, 1902. Antarctic. This ­enigmatic species was described from specimens assumed to be juveniles due to the lack of gonopores on the apical system. Aporocidaris milleri (A. Agassiz, 1898). East Pacific, Antarctic. Aporocidaris usarpi Mooi et al., 2000. Antarctic waters. Remarks: It is very likely that A. fragilis from the North Pacific and A. milleri, initially reported from the bathyal of the Panamic region, are synonymous. Fell (1976) put also A. antarctica into that species. However, Lockhart (2006, unpublished thesis) considered these two latter not to be conspecific. Both species, A. antarctica and Aporocidaris milleri, are reported to live sympatrically in the depths of the South Sandwich Trench. The collected material could easily be separated by their different color, A. antarctica being deep purple and A. milleri being yellowish. But the more important difference lies in the fact that the specimens of A. antarctica were infected by

4.1.1 Order: Cidaroida Claus, 1880 



a parasitic amphipod (Lepidepecreella andeep Berge, Vader & Lockhart, 2004), whereas those of A. milleri were not. Aporocidaris antarctica Mortensen, 1909 (Fig. 4.33 C, D) Test: Maximum reported diameter of test 45 mm. Apical system: Regularly tuberculated. Ambulacra: Narrow, interporiferous zone mostly set with a single marginal tubercle. Interambulacra: Areoles aborally well separated, on oral side confluent. Primary spines: Rather brittle.

A

D

 75

Color: In live specimens, the test and secondary spines are deep purple; the primary spines are white. Even if a specimen is paler, slightly resembling A. milleri, the oral side with the peristome is distinctly purple. Distribution: Circum-Antarctic. Aporocidaris eltaniana Mooi, David, Fell & Choné, 2000 (Fig. 4.33 E) Test: Largest recorded diameter 45 mm. Height about half the diameter; apical system about 60 % the diameter and usually only slightly raised; gonopores near to

C

B

E

F

Fig. 4.33: (A, B) Juveniles of Rhynchocidaris triplopora. (A) Aboral side: the embryo has developed short spines and the first five podia. In the center a small anal plate has just occurred. (B) Oral side: within the buccal plates the lantern begins to develop. The juvenile starts to feed when the periproct and the mouth have open. Scale: 1 mm (Mortensen 1909). (C, D) Aporocidaris antarctica. Primary spines: from left to right: refers from oral to aboral side. Scale: 5 mm (Mortensen 1909). (D) Aboral side with remaining spines, diameter of test 14 mm; East of Prydz Bay, Antarctic. ZMH Cotype E 312. The gonopores are not yet fully developed. (E) Spines of Aporocidaris eltaniana. Oral primary spine, aboral primary spine. Scale: 10 mm. Redrawn after Mooi et al. 2000. (F) Spines of Aporocidaris usarpi. Oral primary spine, aboral primary spine. Scale: 10 mm. Redrawn after Mooi et al. 2000.

76 

 4.1 Subclass Cidaroidea Smith, 1984

the outer edge of genital plates, in females extending into interambulacra. Areoles: Strongly transverse ovate below the ambitus, confluent. Primary spines: Cylindrical with blunt or concave tip, set with longitudinal rows of small spinules; milled ring distinct; oral primaries strongly curved and very typical in bearing well developed thorns that project mainly laterally; scrobicular spines more or less cylindrical, not club-shaped. Distribution: Off Livingston Island, South Shetland Islands, 884 to 1,437 m. Aporocidaris fragilis A. Agassiz & H. L. Clark, 1907 (Fig. 4.34 A, B) Remark: It is debatable, whether this species should be synonymized with A. milleri (see below) or both again with Aporocidaris antarctica. The morphological differences of these species are exceedingly small. Fell (1976, p. 205) pointed out that the characteristics believed to distinguish A. fragilis from A. milleri all fall into the range of variation found in A. milleri. Distribution: This nominal species is found in the North Pacific from Kamtchatka to Alaska at depths of more than 3,500 m. Aporocidaris incerta Koehler, 1902 (Fig. 4.35, 4.36, 4.37) Test: Very low; 40–50 % of horizontal diameter, flattened above and below, with strongly arched sides; no inflated apical disc, diameter hardly exceeding 30 mm. Apical system: Ocular plates widely exsert, genital plates large, gonopores in females not piercing the genital plates, but the interambulacral median sutures on the oral side or even at the peristomial edge; gonopores in males small, transferred midway down the test in the median sutures of the interambulacra. Ambulacra: Pore pairs oblique. Spines: In length, almost reaching diameter of test, ­tapering to the top, set with tiny filaments. Peristome: In females, ring-shaped recess on the membrane along the edge of the corona. Color: Preserved specimens are dark brown. Distribution: This species lives around the Antarctic continent: in the Bellingshausen Sea, off South Georgia and eastern Antarctica and in the Ross Sea at a depth of 100 to 300 m. Remark: Koehler reported of five young specimens, which he called Porocidaris incerta. The largest were 12.5 and 14 mm in diameter showing no gonopores. It was the first description of a high Antarctic extant cidaroid species.

H. L. Clark (1907) included the species in the genus Aporocidaris. Meanwhile, the type material found by the SV Belgica in the Bellingshausen Sea at 100–300 m is lost or damaged. When Mortensen examined the material from the German South Polar Expedition 1909, he noticed among a couple of Rhynchocidaris triplopora from the South Shetland Islands some specimens looking different: 1. The test is conspicuously lower and, including the podia, more darkly pigmented than the normal specimens. 2. The pedicellarian epithelium is thickened and also darker pigmented. 3. T  he primary spines are set with filaments originating in the innermost part of the layers. 4. In females, the genital plates are not pierced by a gonopore, but the gonoducts lead downward each forming an opening at the adoral median suture of the interambulacra or at the edge of the peristome. In males, the gonoduct leads to an opening midway down the test in the interambulacrum. Mortensen assumed that these “unusual” echinoids were infected by a parasite that he described as Echinophyces mirabilis. However, he was not able to explain how the parasite, housing in the calcareous primary spines, could cause such drastic modifications in soft tissues and especially in the inner bauplan. In the following years, “unusual” specimens were found also among populations of Ctenocidaris speciosa off South Georgia and Ctenocidaris perrieri in the Ross Sea and eastern Antarctica. After 2002, when several Antarctic expeditions had been undertaken, more specimens were available and subject of intensive studies (Lockhart 2006, unpublished thesis). These research, molecular and morphological, revealed that all “unusual” specimens represent a taxon of its own, quite distinct not only from R. triplopora, C. speciosa, and C. perrieri, but also from all other ctenocidarines. She found out that this taxon was already described in former literature as Aporocidaris incerta, first by Koehler (1902) and later augmented by Mortensen (1928): “In specimen 1 (the peristome) is distinctly pentagonal, there being a conspicuous notch in each interambulacrum”. This hint obviously referred to the openings of the gonoducts, formerly reported for the “unusual specimens”. This peculiar new taxon is not yet officially described, its name proposed by Lockhart (2006, unpublished PhD thesis) is still a nomen nudum, although it is listed in WoRMS (Kroh & Mooi 2010, World Echinoid Database. http://www.marinespecies.org/echinoidea).

4.1.1 Order: Cidaroida Claus, 1880 



A

 77

B

F

D

C

Fig. 4.34: (A, B) Aporocidaris fragilis with some remaining spines. (A) Aboral side, diameter of test 23 mm; Alaska, USA, 3,550 m deep. ZMUC. The primary spines are long and slender, set with tiny thorns. (B) Oral side with remaining spines. (C, D) Aporocidaris milleri with spines. (C) Side view, diameter of test 22 mm; Acapulco, Mexico. ZMUC. The large apical system is raised. (D) Aboral side with two primary spines, diameter 22 mm; Acapulco, Mexico.

78 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

D C

Fig. 4.35: Aporocidaris incerta. (A) Aboral side of female, diameter 19 mm; Scotia Sea. ZMH. There are no gonopores developed. (B) Oral side: the peristomial membrane is recessed at the edge of the test and there open gonopores in the interambulacra (see arrows). (C) Side view. The test is low, the upper side with the apical system only very slightly inflated. (D) Specimen with spines, test diameter 21 mm; Scotia Sea. AWI. The spines are set with fine filaments.

Literature: Mortensen 1909, 1928, 1936, 1950; Mortensen & Rosenvinge 1910; Koehler 1912a,b; Fell 1976, ­unpublished PhD thesis; David et al. 2005; Lockhart 2006, unpublished PhD thesis. Aporocidaris milleri A. Agassiz, 1898 (Fig. 4.34 C, D) Test: Maximum diameter may reach 45 mm. Ambulacra: Almost straight. Interambulacra: 5–7 plates per column; areoles small and round on the aboral side, slightly wider than high on the oral side. Primary spines: Very slender, moderately long, up to 1.5 the diameter of test, cylindrical; shaft variably set with fine spinules or being smooth and shiny; oral primaries long, flattened, slender, and with coarsely serrated or smooth, undulating edges.

Secondary spines: Simple or weakly club-shaped. Color: Live specimens yellowish with white primary spines. Distribution: The species is common in the deep East Pacific and around Antarctica. Aporocidaris usarpi Mooi, David, Fell & Choné, 2000 (Fig. 4.33 F) Maximum recorded diameter of test about 40 mm. Test: Height about 70 % of diameter inclusive domed apical disc; genital plates large relative to other apical plates. Ambulacra: Pore pairs connected by a constricted passage, lacking the separating bridge. Interambulacra: Areoles round above the ambitus, ovate and confluent below.

4.1.1 Order: Cidaroida Claus, 1880 



A

residual duct

 79

aboral side

apical system radial canal

gonad

test unusually developed gonoduct

oral side

peristome

C

B

III

1 mm

IV

V

Fig. 4.36: Aporocidaris incerta. (A) Diagrammatic cross section: the gonads in A III, A IV, and A V are visible. They consist of eggs of various size, indicating that the reproduction is continuous. The eggs are not released through gonopores in the genital plates in the apical system, but the gonoducts lead downward to an opening on the oral side or at the peristomial edge (modified after a drawing of R. Mooi in Lockhart 2006, unpublished thesis). (B) Position of the cross section in A. (C) Close-up of primary spine: the filaments originate from the spine cortex of the cidarid.

Primary spines: In length, 1–1.5 the diameter of test, cylindrical, shaft set with small irregularly arranged bumps or spinules, distally rather in series; neck of aboral primaries glossy, porcellaneous, and distinctly swollen in larger specimens; oral primaries flattened

with laterally serrated keels, widened proximally tapering to the tip. Secondary spines: Almost cylindrical and slightly clubshaped; scrobicular spines only slightly longer than other secondaries.

80 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

F

Fig. 4.37: Aporocidaris incerta. Anomalous female, diameter of test 30 mm; South Georgia. ZMUC (as Ctenocidaris speciosa). This specimen has six columns of ambulacra and interambulacra, and in consequence, six genital and ocular plates in the apical disc and six gonopores on the oral side. (A) Aboral side: there are no traces of gonopores in the genital plates. (B) Side view: the test is conspicuously low with flattened aboral and oral sides. (C) Oral side: five of the gonopores open into notches at the peristomial edge positioned at the median line of the interambulacra; the sixth opens more distant from the edge in the median suture. The peristomial membrane is distally deeply recessed. (The holes in the menbrane are likely to be artifacts.)

Genus Ctenocidaris Mortensen, 1910 Scrobicular spines flattened and in a shape distinct from other secondaries, which are cylindrical with blunt tips or more or less club-shaped; ambulacra without naked median suture, interambulacra in some species with narrow, naked, but never sunken midline. Test: Low, flattened above and below, apical disc hardly raised. Apical system: In width, about half the test diameter, ocular plates exsert to insert, ocular pores encircled by a rim; gonopores in females larger than in males, sometime extending into interambulacra; plates usually covered more or less densely by tubercles. Ambulacra: Almost straight; pore pairs small and obliquely positioned, often connected lacking the interporal bridge; marginal tubercles in rows, smaller secondary tubercles variably distributed; pore zones not sunken. Interambulacra: Sunken areoles, scrobicular tubercles not differentiated; extrascrobicular area densely tuberculated, usually no naked midline.

Peristome: About 50 % of test diameter. Primary spines: Long, cylindrical with short collar and distinct neck; shaft set with irregular thorny or rounded spinules. Scrobicular spines: Flattened; secondary spines cylindrical with blunt or club-shaped tips. Biology: It is very likely that all species are brood-protecting their young. Eight species are included in this genus: Ctenocidaris aotearoa MacKnight, 1974. Off South Island of New Zealand. Ctenocidaris geliberti Koehler, 1912. Circum-Antarctic. Ctenocidaris nutrix Thomson, 1876. Kerguelen Islands, Heard Island. Ctenocidaris perrieri Koehler, 1912. Circum-Antarctic, ­southern Chile. Ctenocidaris polyplax Mortensen, 1950. East Antarctic. Ctenocidaris rugosa Koehler, 1926. Circum-Antarctic, Scotia Sea, southern Chile. Ctenocidaris speciosa Mortensen, 1910. Circum-Antarctic, Scotia Sea, Falkland Islands.



Ctenocidaris spinosa Koehler, 1926. Circum-Antarctic, Scotia Sea, southern Chile. The species are closely related and hardly distinguishable in test characteristics. They differ mainly by the shape of their primary and scrobicular spines, although there may be considerable variation. Ctenocidaris aotearoa McKnight, 1974 Test: Diameter may reach about 30 mm. Test: Flattened above and below. Apical system: Flat; ocular pores distal, plates with two transverse rows of tubercles on inner part; genital plates with 3 or 4 transverse rows of tubercles. Ambulacra: About a quarter of interambulacra in width; marginal tubercles spaced, subequal inner tubercle subambitally; pore pair oblique. Interambulacra: Median area about two thirds of areole in width. Primary spines: About 2 times the diameter of test in length, tapering; milled ring conspicuous; neck 3  mm long; rows of spinules prominent forming distinct ridges; usually directed distally, but sometimes also toward the base; some spines may carry basally large protruding thorns; oral ­ primaries curved with truncated tip and serrate edges. Secondary spines: Slightly flattened and with blunt tips. Large and wide forms of globiferous pedicellariae absent (Lockhart, personal communication). Color: Generally brown, primary spines may be white or brownish. Distribution: Off the southeast coast of New Zealand. Bathymetric range 1,280 to 1,600 m. Ctenocidaris geliberti Koehler, 1912 (Fig. 4.38 A, G) Test diameter usually reaches 50 mm, maximum recorded size 80 mm. Apical system: About 40–50 % of test diameter, ocular plates exsert in small specimens, becoming insert in larger ones. Interambulacra: No naked band along the median suture. Primary spines: Long and cylindrical, shaft either smooth or set with very small, serially arranged oval bumps or spinules, creating a rugose feeling; tips slightly flaring; oral primaries smooth to slightly serrated and more or less ­spatulate. Color: In life, the test is light yellow; the primary spines are usually mauve to brown with greenish white tips. In contrast, the spines of C. gigantea are mostly whitish.

4.1.1 Order: Cidaroida Claus, 1880 

 81

Distribution: This species is believed to be circumAntarctic. Bathymetric range 20 to 745 m. (Because often C. geliberti was misidentified as Homalocidaris gigantea, the records are not precise.) Ctenocidaris (Eurocidaris) nutrix Thomson, 1876 (Fig. 4.38 B, F) Small form with the test diameter usually not more than 30 mm, maximum recorded size 40 mm. Test: In height, about 50 % of diameter; apical system flat. Primary spines: Simple, cylindrical; shaft covered by small, sharp spinules in distinct series; oral primaries simple, not differentiated. Color: Preserved specimens are light brown to red brown, primary spines light brown with pink collar and white neck. Remark: Mortensen (1909) established the subgenus Eurocidaris for this species because its oral primary spines are simple instead of serrated as in other Ctenocidaris. Besides, C. nutrix nutrix Mortensen (1928) recognized a second form, C. nutrix longispina with primary spines 2 to 2.5 times the diameter of test. Distribution: Ctenocidaris nutrix nutrix is the only cidarid that lives around the subantarctic Kerguelen and Heard Islands at depths of 23 to 650 m. The longispina form is known from Heard Island and along the Antarctic continent from Prydz Bay to Coats Land at the eastern side of the Weddell Sea. Bathymetric range 200 to 530 m. Ctenocidaris perrieri Koehler, 1912 (Fig. 4.38 C, 4.39 B, G) Usually reaching a horizontal diameter of about 50 mm, maximum recorded size 70 mm. Interambulacra: Secondary tubercles dense, no naked midline, but suture is marked. Primary spines: The aboral slender, in length up to 2.5 times the horizontal diameter; shaft covered with dense and coarse thorns more or less irregularly set; oral primaries slightly widened with coarse serrations. Color: In life, the specimens are red brown, often very dark; preserved specimens purplish brown to straw beige; spines brown with purple neck. Distribution: This species is circum-Antarctic. Bathymetric range 31 to 2,468  m, commonly between 200 and 700 m. Biology: More than 50 juveniles were found on the peristomial membrane, reaching 5 mm in test diameter plus 5 mm spine length (Lockhart et al. 1994).

82 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

C

D

E

F

E G

H

Fig. 4.38: (A–F) Aboral (left) and oral (right) primary spines of species of Ctenocidaris. (A) Ctenocidaris geliberti. (B) Ctenocidaris nutrix. (C) Ctenocidaris perrieri. (D) Ctenocidaris rugosa. (E) Ctenocidaris speciosa. (F) Ctenocidaris spinosa. Scale: 4 mm (redrawn and modified after David et al. 2005). The drawings show for each species only a single example, in the appropriate descriptions additional notes, e.g. on variations can be found. (G) Ctenocidaris geliberti with spines. Side view, diameter of test 53 mm; Scotia Sea. ZMUC. The base of the shaft is thickened toward the milled ring. (H) Ctenocidaris nutrix. Aboral side with spines, test diameter 23 mm; Kerguelen Islands. ZMUC. The primary spines are short, hardly exceeding the test diameter.

Ctenocidaris polyplax Mortensen, 1950 Only a single specimen is known. It is distinguished from the other species of Ctenocidaris by its large number of interambulacral plates, 10 to 11 plates per series. Diameter 40 mm. Restricted to East Antarctica, Enderby Land. Ctenocidaris rugosa Koehler, 1926 (Fig. 4.38 D, 4.39 A) Maximum diameter of test 80  mm, mostly 50–60  mm. This species is equal to C. geliberti in general appearance differing only in the more rugose primary spines, the spinules covering the shaft being more distinct and arranged in longitudinal series.

Distribution: This species is known from around Antarctica, except in the Ross Sea. Bathymetric range 98 to 810 m. Remark: Some authors think C. rugosa synonymous with C. geliberti (Fell 1976, adopted the suggestion of Mortensen 1928). Ctenocidaris speciosa Mortensen, 1910 (Fig. 4.38 E, 4.39 C) Test: Maximum recorded test diameter 62 mm. Apical system: About 40–50 % of horizontal diameter; ocular plates exsert in small specimens, becoming insert in larger ones.

4.1.1 Order: Cidaroida Claus, 1880 



A

C

B

E

 83

D

F

G

Fig. 4.39: (A) Ctenocidaris rugosa. Aboral side with spines, diameter of test 19 mm; Australian Antarctic. (B) Ctenocidaris perrieri. Primary spines. longest spine 62 mm; Weddell Sea, Antarctic, AWI. (C) Ctenocidaris speciosa. Primary spines, longest 80 mm; Weddell Sea, AWI. (D–F) Ctenocidaris spinosa. (D) Primary spines. Longest spine 50 mm; Weddell Sea, AWI. (E) Aboral side with spines, test diameter 13 mm; Weddell Sea, AWI. The primary spines are strongly serrated. (F) Female with juveniles. Diameter of test 45 mm; Weddell Sea, AWI. The juveniles are sheltered on the peristome below the widened primary spines. (G) Ctenocidaris perrieri. Side view with some remaining spines, diameter of test 67 mm; Weddell Sea, AWI.

Interambulacra: No distinct naked median suture. Primary spines: Aborally set with longitudinal rows of small to very small spinules. Appearing almost smooth; oral primaries show very typical lateral rows of blunt, coarse spinules more or less fused. Color: General appearance in living specimens dark purple with white primary spines.

Distribution: This species is restricted to the Weddell and Scotia Seas, at depths ranging from 75 to 1,681 m. Remark: Ctenocidaris perrieri, C. speciosa, and C. spinosa are very closely related. They differ mainly in the ornamentation of their aboral and oral primary spines. However, the intraspecific variation is considerable sometimes causing morphological overlap. Further studies are needed.

84 

 4.1 Subclass Cidaroidea Smith, 1984

Ctenocidaris spinosa Koehler, 1926 (Fig. 4.38 F, 4.39 D–F) Test: Maximum recorded test diameter 52 mm. Interambulacra: Conspicuous naked area along the median suture. Primary spines: Aborally with coarse and sharp thorns arranged in about eight longitudinal series sometimes fusing into spiny ridges; oral primaries spear-shaped, the lateral serrations becoming wings. Color: In general, dark brown, secondary spines red brown, primary spines grayish with red brown collar and red pink neck. Distribution: This species is recorded in the Weddell Sea, off Kapp Norvegia, and off Queen Mary Coast. Bathymetric range 64 to 898 m.

A

C

Biology: The species is brood-protecting, but there are no depressed areas recorded on the peristome. Genus Homalocidaris Mortensen, 1928 The genus is monospecific. Homalocidaris gigantea H. L. Clark, 1925 (Fig. 4.40) Test: Low, flattened above and below, apical disc hardly raised; diameter up to 65 mm. Apical system: In width about half the test diameter, ocular plates exsert to insert, ocular pores encircled by a rim; gonopores in females larger than in males, sometime extending into interambulacra; plates usually covered more or less densely by tubercles.

B

D

E

Fig. 4.40: Homalocidaris gigantea. (A) Aboral side with spines, diameter of test 45 mm; Weddell Sea. AWI. The white primary spines are as long as the diameter of test. (B) Side view of test, diameter 55 mm; Scotia Sea. ZMH. (C) Oral side of female, test diameter 59 mm; Scotia Sea. ZMH. The female parent carries its juveniles on the depressed peristomial membrane. (D) Juvenile, diameter of test ca. 2 mm. (E) Primary spines, aboral (left) and oral (right). Scale: 4 mm. Redrawn and modified after David et al. (2005).



Ambulacra: Almost straight; pore pairs small and obliquely positioned, often connected lacking the interporal bridge; marginal tubercles in rows, smaller secondary tubercles variably distributed; pore zones not sunken. Interambulacra: Sunken areoles, scrobicular tubercles not differentiated; extrascrobicular area densely tuberculated, usually no naked midline. Peristome: About 50 % of test diameter. This species is almost equal to C. geliberti in test sculpture. It has enlarged areoles mostly being confluent. The two species usually differ in the shape of their oral primaries: in Ctenocidaris geliberti, they may be slightly widened and the lateral edges may be irregularly indented; in H. gigantea, they are straight cut with one or two longitudinal depressions distally. However, there occurs considerable variation. Furthermore, they differ in the base of the primary spines: in Homalocidaris gigantea, the prominent milled ring forms a sort of platform around the spine, while in C. geliberti, the milled ring is much less prominent but the base itself is often thickened. In both species, the shaft of the aboral primary spines is smooth to slightly rugose. Often, in Ctenocidaris geliberti, the color of the spines is mauve; in H. gigantea, more white. The scrobicular spines of H. gigantea are distinctly flattened; the other secondaries are slightly clubshaped. Color: Test light brown, primary spines white with rose collar and brownish tip, secondary spines light brown or beige. In contrast, the primaries of C. geliberti are often mauve to brown. Distribution: This species is circum-Antarctic and in the Scotia Sea. Depth range 150 to 2,315 m, most common at depths down to 750 m. Biology: In Homalocidaris gigantea, the muscles of the primary spines are particularly large being attached at the broad milled ring. With these muscles, the echinoid is capable of rapid locomotion. Genus Notocidaris Mortensen, 1909 In this genus, the scrobicular spines have the same shape as the other secondaries, being simple, cylindrical, or club-shaped. Test: Low. Apical system: About 50–60 % of test diameter, all plates usually well tuberculated; ocular plates more or less exsert, ocular pores rimmed; gonopores in females larger than in males, partly extending into interambulacra. Ambulacra: Almost straight; pore pairs small and oblique, interporal bridge often lacking, the pores being coalesced; marginal tubercles in regular series, median

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 85

space with smaller secondaries, leaving usually no naked midzone; pore zones not sunken. Interambulacra: Up to 10 plates per column; areoles slightly sunken; scrobicular tubercles not differentiated from other secondary tubercles; extrascrobicular area uniformly set with secondary tubercles, naked median suture may be conspicuously incised. Peristome: Relatively few ambulacral plates, inter­ ambulacral plates not extending to mouth. Primary spines: Long and cylindrical, shaft with lateral flanges or wings; thorns, if present, sometimes only proximately. Biology: All species of Notocidaris are likely to be direct developers, brood-protecting their juveniles on the depressed edges of the peristome. Probably, the genus consists of seven species: Notocidaris gaussensis Mortensen, 1909. Circum-Antarctic, except Ross Sea. Notocidaris hastata Mortensen, 1909. Antarctic Peninsula, Falkland Island, southern Chile, East Antarctic, Wilkes Land. Notocidaris lanceolata Mooi et  al., 2000. Antarctic, Weddell Sea to Wilkes Land, Ross Sea. Notocidaris mortenseni Koehler, 1900. Circum-Antarctic. Notocidaris platyacantha H. L. Clark, 1925. East Antarctica and Ross Sea. Notocidaris remigera Mortensen, 1950. East Antarctica. Notocidaris sp. Scotia Sea. Typically, the species are rather well separated by the shape of their primary spines. But the range of variation recorded for each species is large and spine ornamentation may overlap. The test sculpture shows no reliable difference. Notocidaris gaussensis Mortensen, 1909 (Fig. 4.41 A1, B, C) Typically, the aboral primary spines carry small spinules around the basal shaft, not forming lateral keels. Maximum recorded horizontal diameter 46 mm. Ambulacra: interporiferous zone covered by regular series of marginal tubercles and inner series of hardly smaller secondaries. Primary spines: In length, up to twice the test diameter; cylindrical, shaft smooth with concave tip or sometimes flattened, only proximally set with small spinules or bumps arranged around the whole spine, primaries below the ambitus shorter, gradually becoming flattened with lateral expansions toward the peristome, where the spines look like a ridged arrowhead. Secondary spines: Cylindrical, tip only slightly ­inflated. Color: Preserved specimens are dark purple to light brown, collar and neck red pink, shaft gray yellow.

86 

 4.1 Subclass Cidaroidea Smith, 1984

A

B 2

1

3

4

5

6

C

24 mm

D

1

52 mm

44 mm

2

3

32 mm

E

4

Fig. 4.41: (A) Aboral primary spines of Notocidaris species (see also the appropriate descriptions): (1) Notocidaris gaussensis: the very long spine is cylindrical and straight cut at the distal end with a bowl-like depression. Holotype. ZMUH. Scale: 8 mm (from Mortensen 1909). (2) Notocidaris hastata: the spine is sword-shaped with two lateral wings along the whole length of the shaft. Scale: 6 mm (Mortensen 1909). (3) Notocidaris mortenseni: the lateral, more or less serrated wings are widened at the base tapering toward the distal end. Scale: 5 mm (drawn after David 2005). (4) Notocidaris platyacantha: the whole shaft is flattened and slightly widened, concave distally, with conspicuous coarse thorns at the base. Scale: 10 mm (drawn after David 2005). (5) Notocidaris remigera: the shaft is greatly widened and conspicuously concave toward the distal end. Scale: 10 mm (drawn after David 2005). (6) Notocidaris sp: the shaft is set with two lateral and two dorso-ventral sharp edges running up to the point. Scale: 5 mm. (B, C) Notocidaris gaussensis. (B) Side view with spines, diameter 26 mm; German South Polar Expedition. Cotype ZMH E 310. (C) Aboral side of female, diameter 26 mm. ZMUC ECH 379. (D) Notocidaris hastata. German South Polar Expedition, off Wilhelm II Land, 2,450–3,397 m. Types MfN Berlin. (1) Primary spine. Syntype Ech 5452. (2) Primary spine. Holotype Ech 5453. (3) Primary spine. Syntype Ech 5454. (4) Test and primary spines. Diameter of test 14 mm. Holotype MfN Ech 5453 (photos by C. Neumann, MfN). (E) Notocidaris lanceolata: (1) Oral primary spine: it is spear-shaped with fine, shallow lateral serrations. (2) Aboral primary spine: the shaft bears thorns only at the basal part, distally becoming irregular, low bumps. Scale: 10 mm. Redrawn after Mooi et al. 2000.



Distribution: This rather rare species is recorded from a few specimens collected around Antarctica, excepting the Ross Sea. Bathymetric range 202 to 1,223 m. Notocidaris hastata Mortensen, 1909 (Fig. 4.41 A2, D) Mortensen’s original description of this species referred to three immature specimens of 13 to 15  mm in test diameter. He emphasized the length of the primary spines as 5 times the diameter. (I have not seen primary spines of that length; obviously, they are broken into pieces). The lateral wings along the shaft are narrow, not parallelsided but tapering to the point and more or less serrated. Main characteristics of the genus. Only the shape of the primary spines distinguishes this species from its congeners. Distribution: As the name has commonly applied to another, more common and as yet, undescribed species of Notocidaris, the geographic range is not confirmed. Mortensen stated as type locality: off Wilhelm II Land. Depth 2,450 to 2,916 m. Notocidaris lanceolata Mooi, David, Fell & Choné, 2000 (Fig. 4.41 E) Test: Maximum recorded test diameter 36 mm. Apical system: Varies from flattened to conspicuously arched; ocular plates broadly insert. Aboral primary spines: About 2 times the diameter of test, with coarse thorns at their base, which are arranged irregularly, becoming strongly reduced and forming series toward the distal end; on the whole the spine is keeled laterally and vertically, giving it a lance-like appearance; oral primaries widened and flattened. Color: In general, beige with shiny purple beige neck. Distribution: The species is found off the Antarctic continent in the Ross Sea at depths of 2,005 to 2,421 m and in the Weddell Sea from 332 to 2,421 m. Notocidaris mortenseni Koehler, 1900 (Fig. 4.41 A3, 4.42) Test: Maximum recorded test diameter 40 mm. Aboral primary spines: Two broad wing-like expansions along the lower part of the shaft; distally, they are rod-like and covered with some low granules arranged more or less in rows. In larger specimens, the wings may extend to the end of the spine. The surface of the spines is smooth and somewhat shiny. The length of the aboral primary spines may reach 3 times the horizontal diameter, but usually less. Oral primary spines: Spear-shaped. Secondary spines: Slender and slightly club-shaped. Color: The test of live specimens may be red to dark purple, primary spines gray to pink or white with a purple neck. The secondary spines are brown to dark purple brown.

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 87

Distribution: Notocidaris mortenseni is known from the Bellingshausen Sea, the South Shetland Islands, Weddell Sea, Wilkes Land, and the Ross Sea. Bathymetric range about 100 to 1,240 m. Notocidaris platyacantha H. L. Clark, 1925 (Fig. 4.41 A4, 4.43 A) The largest recorded test diameter is about 60 mm. Aboral primary spines: Gradually widening from the base to the tip or with parallel sides, distally flattened or concave, lower part often with several sharp thorns at the lateral edges; neck short, shaft smooth and shiny; length 1.4 to 2.5 times horizontal diameter of test; oral primaries flattened. Secondary spines: Slender and slightly flattened. Color: Test light brown to dark purplish brown; primary spines beige to pinkish white, secondary spines beige to purplish brown. Distribution: The species is known from eastern Antarctica and the Ross Sea. A single specimen has been reported from the South Shetland Island. Bathymetric range 184 to 1,233 m. Notocidaris remigera Mortensen, 1950 (Fig. 4.41 A5, 4.43 B) Maximum recorded test diameter about 60  mm, usually smaller. Aboral primary spines: Greatly widened, up to 30 mm; strongly concave looking like a shoehorn. Distribution: This species has been only reported from Prydz Bay and the Prince Olav and Mac Robertson Coast along the eastern Antarctic continent. Bathymetric range 200 to 530 m. Biology: The upper primary spines are often set by various epizoans like bryozoans and polychaetes. Sponges can reach a large size. Lockhart et al. (1994) reported 96 juveniles of about 2 mm in diameter on a female of 48 mm diameter and even 140 embryos of about 1.5 mm diameter on another female of 44 mm. Notocidaris sp. (Fig. 4.41 A6, 4.43 C, D) Primary spines: With two lateral and two dorso-ventral ridges or sharp edges running along the entire length of the shaft; surface smooth and more or less shiny; in some specimens, there may be coarse serrations near the base. Color: Alive, the test is covered with a pale pink epithelium; primary spines greenish white with a faint pink or mauve tint proximally, secondary spines white to pinkish; cleaned tests are white. Distribution: Notocidaris sp. is found in the Scotia Sea around the South Shetland and South Orkney Islands. Confirmed bathymetric range from 154 to 447 m.

88 

 4.1 Subclass Cidaroidea Smith, 1984

A

C

B

D

Fig. 4.42: (A–D) Notocidaris mortenseni. Oral side of female, diameter 31 mm; Weddell Sea. AWI. The peristomial membrane is deeply recessed. (B) Oral side with secondary and a few primary spines. (C) Side view with long primary spines, the longest one reaches a length of 70 mm. The distal shaft is rod-like, smooth, and somewhat shiny; along the proximal part, two distinct wings are developed. (E) Juvenile. Diameter of test about 2.5 mm; Scotia Sea. ZMH. The spines are stout and very finely serrated.

The species is most likely to be confined to the shelf, in contrast to Notocidaris hastata, which lives in the deep sea below 2,000 to more than 4,000 m. Remark: Notocidaris sp. was frequently confounded (see David et al. 2000, 2005) with N. hastata especially because it occurs more often than the obviously rather rare real N. hastata. Genus Rhynchocidaris Mortensen, 1909 The genus is monospecific.

Rhynchocidaris triplopora Mortensen, 1909 (Fig. 4.33 A, B, 4.44) In his description, Mortensen (1909) emphasized that there were 3 pores piercing the adoral ambulacral plates. But an enlarged neuropore, which leads to this tripartite appearance, may also occur in other Antarctic cidarids (Lockhart, personal communication). Test: Low, diameter not exceeding 30 mm. Apical system: About 50–60 % of test diameter; gonopores in the distal edges.

4.1.1 Order: Cidaroida Claus, 1880 



A

C

B

D

Fig. 4.43: (A) Notocidaris platyacantha. Side view with spines, diameter of test 24 mm, longest spine 38 mm; Antarctic. ZMUC. (B) Notocidaris remigera. Aboral side with some spines, diameter of test 47 mm; Antarctic. ZMUC ECH 357. The loose intact primary spines are placed around the test, longest spine 62 mm. (C, D) Notocidaris sp. Side view of female, diameter of test 20 mm; Weddell Sea. AWI. The gonopores are large. (D) Oral side of female, test diameter 22 mm; Scotia Sea. ZMH. The bright red juveniles grow on the recessed peristomial membrane sheltered by the widened and curved oral spines of the female parent.

 89

90 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

1

3 mm

3 mm

2

10 mm 3

D

E

Fig. 4.44: Rhynchocidaris triplopora. (A) Aboral side of male, test diameter 20 mm; Scotia Sea, Antarctica. AWI. The apical system is densely tuberculated. (B) Spines: (1) Secondary spine. (2) Aboral primary spine. (3) Oral primary spines. Mortensen 1909. (C) Close-up of primary spine with tiny, sharp thorns. Scale: 3 mm. (D) Specimen with spines, aboral side, diameter with secondary spines 23 mm; Scotia Sea. AWI. The whole surface of the test is densely covered by uniform, erect, strongly club-shaped secondary spines, giving the echinoid its typical globular appearance. (E) Oral side with spines.

Ambulacra and interambulacra: Uniform secondary tuberculation, no naked median zones. Peristome: Non-ambulacral plates not reaching the mouth. Primary spines: Simple and pointed, set with fine thorns; in length, 1–1.5 the diameter of test; oral primaries flattened. Secondary spines: Very characteristic in being strongly club-shaped with an almost globular tip, dense and uniform spination, giving the species a globular appearance.

Color: Preserved specimens ochre to light purplish brown, primary spines grayish brown with tan or rosy neck; in living specimens, the epithelium is a burgundy color. Distribution: This species is known from around Antarctica and the Scotia Sea. Depth 62 to 1,230 m. Remark: It is conspicuous that the genus Rhynchocidaris­ includes only a single species despite the fact that it is involved in the influences of the ACC just like the other strongly radiating ctenocidarid genera. Lockhart



(­ personal communication) thinks that Rhynchocidaris is not a valid genus, and the species triplopora is better placed in another ctenocidarine genus. The characteristics on which the genus and species were established by Mortensen (1909) are not unique, the tripartite pores occurring also in other species. The entire subfamily needs a revision.

Subfamily Goniocidarinae Mortensen, 1928 This subfamily is characterized by deeply depressed furrows along the vertical plate sutures and/or pits in the sutural triple junctions on interambulacra and ambulacra. Six genera are included in this subfamily: Austrocidaris H. L. Clark, 1907. Four species, Subantarctic. Goniocidaris Desor in L. Agassiz & Desor, 1846. Numerous species, Indo-West Pacific. Ogmocidaris Mortensen, 1921. A single species, New Zealand. Psilocidaris Mortensen, 1927. A single species, Philippines. Rhopalocidaris Mortensen, 1927. Three species, Indo-West Pacific. Schizocidaris Mortensen, 1903. Three species, Philippines and Malayan Archipelago.

Fig. 4.45: Goniocidaris tubaria. Side view of test, diameter 41 mm; off Sydney, New South Wales, Australia. The median and the horizontal sutures in ambulacra and interambulacra are naked and depressed forming conspicuous furrows and grooves.

Genus Austrocidaris H. L. Clark, 1907 The systematic place of Austrocidaris is still being discussed: Mortensen (1928) and Fell (1976, unpublished thesis) kept it in the Ctenocidarinae. A. B. Smith moved it some years ago to the Goniocidarinae. It is also placed by

4.1.1 Order: Cidaroida Claus, 1880 

 91

Kroh & Mooi (2010) in that subfamily. However, Lockhart (2006; unpublished thesis), having studied the Antarctic cidarids for many years, suggests to make it a subfamily of its own. This genus is well differentiated from the Ctenocidarinae by brooding its young on the apical system. The ctenocidarine echinoids shelter their young on the peristome. Austrocidaris differs from the other goniocidarines by the vertical naked depressions along their median sutures in the interambulacra: they do not extend at all into the horizontal sutures as in Goniocidaris. The genus consists of four species. Austrocidaris canaliculata A. Agassiz, 1863 Austrocidaris lorioli Mortensen, 1903 Austrocidaris pawsoni McKnight, 1974 Austrocidaris spinulosa Mortensen, 1910 Literature: Mortensen 1903, 1910, 1928; Bernasconi 1963, 1969; McKnight 1974; Larrain 1975; Fell 1976 (unpublished thesis); David et  al. 2000, 2005, 2009; Lockhart 2006 (unpublished thesis). Test: Flattened above and below. Apical system: About 50 % of diameter; in females more or less depressed (before and during brooding), serving as marsupium; gonopores in the distal most edge; ocular plates broadly insert, all plates covered with sparse, small tubercles except around anus, periproct large with numerous plates of similar size sometimes expanding between genital and ocular plates; ocular pores not rimmed. Ambulacra: Slightly sinuous, pore pairs oblique and close to each other; interporiferous zone narrow with a marginal and one or two small internal tubercles per plate; distinct median furrow. Interambulacra: Deeply depressed and non-confluent areoles, which are transversely oval and almost covering the whole plate; surrounded mainly by the distinctly differentiated scrobicular tubercles, extrascrobicular zone very narrow; sharply limited, depressed median furrow with steep sides and flat floor, not extending into horizontal sutures. Peristome: About 10 ambulacral plates per column; interambulacral plates reaching the mouth. Primary spines: Long and cylindrical, shaft with fine granulation, with and without conspicuous thorns; cortical hair dense; oral primaries simple with very fine, ridged granules. Secondary spines: Flattened, scale-like, or slightly tapering with blunt tip; somewhat appressed. Biology: The species of Austrocidaris are direct developers. Reproduction appears to occur aseasonally, but not

92 

 4.1 Subclass Cidaroidea Smith, 1984

c­ ontinuously. The single cohort of young is brood-protected on the sunken apical plates – in contrast to ctenocidarines and some species of Goniocidaris, where the growing juveniles are housed on the peristome. In times of brooding, the females show usually the whole apical disc more or less depressed. The adapical primary spines are rather short forming a cone to cover the young. This method of brood-protecting avoids the risky transfer of the eggs from the gonopores in the apical system down the test to the peristome, increasing the success of reproduction (Lockhart, unpublished thesis 2006).

Austrocidaris canaliculata A. Agassiz, 1863 (Fig. 4.46 A–C) Test: Maximum diameter of test 42 mm, usually not more than 35 mm. In height, approximately half the horizontal diameter.

B

A

C

Remark: This genus is not a real Antarctic echinoid as it is largely restricted to the Argentinean coast and the southern most part of South America, barely crossing the Antarctic Convergence.

D

E

Fig. 4.46: (A–C) Austrocidaris canaliculata. Aboral side of test, diameter 31 mm; northwest of the Falkland Islands. The apical system in females is in times of brooding deeply sunken serving as marsupium. (B) Side view of test: the median suture of the interambulacra is a sharply limited and deeply sunken furrow. The areoles are slightly rectangular as they tend to have straight and parallel vertical sides. (C) Aboral side with spines, diameter of test 36 mm; off Patagonia, Argentina. The spines are cylindrical and relatively short. (D, E) Austrocidaris spinulosa. Aboral side with spines, diameter of test 30 mm; off Mar del Plata, Argentina. The long spines are fully set with coarse thorns. (E) Oblique view, test diameter 31 mm, spine 82 mm; off Mar del Plata, Argentina. The long spines carry thorns only on the basal shaft.



Apical system: Ocular plates not much smaller than genital plates. Interambulacra: Ambital areoles about 1.5 times wider than high, slightly rectangular. Peristome: Pentagonal. Primary spines: In length, barely exceeding horizontal diameter of test in adults, in young longer; short neck and long, often shiny collar; shaft set with small, smooth granules, more or less arranged in rows; with blunt tip, distally sometimes flattened; oral primaries slender with very fine granules. Color: Preserved specimens are straw beige with ochre to red brown primary spines, the neck being orange pink. Distribution: This species is known along the Argentinean coast from the Rio de la Plata to Tierra del Fuego and around the Falkland Islands. It was also collected from the entire Magellan Strait to the Pacific side. The bathymetric range reaches from the intertidal zone to a depth of 845 m, usually 50 to 300 m. Austrocidaris lorioli Mortensen, 1903 Maximum recorded diameter 37 mm. In morphology, this species seems to be an intermediate form between A. canaliculata and A. spinulosa. It differs from Austrocidaris canaliculata in having longer primary spines, which reach 2–3 times the test diameter, resulting in a more conspicuous milled ring; furthermore the test is higher with fewer plates, and the areoles are more circular. In contrast to A. canaliculata, this species has smooth oral primary spines (McKnight 1974). Distribution: Austrocidaris lorioli has been collected south of the Rio de la Plata at a depth of 600 to 1,080 m and in the Gulf of Penas, Chilean Archipelago, Pacific. Depth 100 to 300 m. Austrocidaris pawsoni McKnight, 1974 Remark: Lockhart (personal communication) is not convinced that Austrocidaris pawsoni is really an Austrocidaris, but thinks it being rather a Ctenocidaris: e.g. the ocular plates are widely exsert, whereas in the species of Austrocidaris, they are broadly insert. Test: Strong, flattened above and below, sides distinctly arched. Maximum recorded diameter 38 mm. Apical system: About 50 % of horizontal diameter, subpentagonal; sparsely tuberculated; ocular plates widely exsert, rimmed ocular pores near to distal edge, genital plates wider than long. Ambulacra: Sinuous, in width about 23–25 % of interambulacra; poriferous zone twice the width of pore zone;

4.1.1 Order: Cidaroida Claus, 1880 

 93

pore pair oblique and close-set; marginal tubercles not contiguous; one inner tubercle. Interambulacra: Transverse oval areoles; areoles shallow, scrobicular tubercles spaced; hardly larger than extrascrobiculars; median space one quarter of areole in width; midline inconspicuous, with horizontal notches or pits in larger specimens. Peristome: Subequal in size to apical system. Primary spines: In length, about twice the diameter of test, set with 16–18 finely serrated ridges; neck and collar of same length, smooth; shaft thickening beyond neck, tapering gradually toward the tip that may be flattened; cortical hairs lower than ridges; oral primaries simple and usually smooth. Scrobicular spines: 4.5  mm long, slightly flattened and tapering to a blunt tip; extrascrobicular spines similar, about 4 mm long; marginal spines about 3.5 to 4 mm in length. Globiferous pedicellariae: Without end tooth, opening subterminal. Color: The test is light brown, primary spines white, newly developed ones may be apricot. Distribution: Off the eastern coast of southern New Zealand, 880 to 1,116 m. Austrocidaris spinulosa Mortensen, 1910 (Fig. 4.46 D, E) Main characteristics of the genus. Test: Maximum recorded diameter 31 mm. Primary spines: This species resembles in its surface structures and its long spines Austrocidaris lorioli. It differs from both the other species in the shape of the primary spines: the shaft is set with distinct thorns over its whole length or has at least spurs on the basal part, which may expand into a veritable rosette. Distribution: This species is recorded from the Falkland Islands, in the Magellan Strait westward to the Pacific and on the Burdwood Bank. Bathymetric range 13 to 641 m. Genus Goniocidaris Desor in L. Agassiz & Desor, 1846 The genus Goniocidaris is characterized by the presence of pits and grooves in the sutures of ambulacra and interambulacra. Test: Usually flattened above and below, may be slightly subconical or subpentagonal. Apical system: About half the test diameter, ocular pores usually with a rim; madreporite hardly enlarged, gonopores in females larger than in males; plates covered by tubercles; periproct pentagonal. Ambulacra: Rather broad interporiferous zones, one marginal tubercle per plate, inner granules; median zone with sunken horizontal and/or vertical sutures; pore pairs ­horizontal and well separated by a wall.

94 

 4.1 Subclass Cidaroidea Smith, 1984

Interambulacra: Deeply depressed areoles; scrobicular tubercles more or less differentiated, extrascrobicular tubercles small and densely set, median zone usually sunken along the vertical and/or horizontal sutures. Peristome: Smaller than apical disc. Primary spines: Very variable with thorns, discs, or irregular basal widenings, often confined to the aboral side of the shaft; longest around ambitus, shorter near the apical disc, smallest on the oral side; cortical hair well ­developed. Globiferous pedicellariae: Large end tooth present. Development: All species are lecithotrophic, i.e. the young developing directly from yolky eggs. In three species from New Zealand, the juveniles are sheltered on the test of the mother around the peristomial edge until they are able to live alone: G. (G.) corona, G. (A.) parasol, and G. (G.) umbraculum. Literature: Mortensen 1927, 1928, 1932, 1939; Fell 1954, 1958; Pawson 1964, Baker 1968; McKnight 1969; Clark & Courtman-Stock 1976; Barker 1984; Hoggett & Rowe 1986; Rowe & Hoggett 1986; Rowe & Gates 1995; Shigei 1986; Miskelly 1998; Tracey et al. 2011; Pierrat et al. 2012. The genus consists of numerous species that have such different aspects and one would hardly regard them as congeneric. Mortensen (1928) distinguished them mainly by the shape of the primary spines. Unfortunately, the ornamentation of the spines vary considerably within a species and transitional forms occur. Mortensen (1928) tried to group the species into five subgenera, but he himself admitted that the value of these subgenera remains problematic. Subgenus Aspidocidaris Mortensen, 1928 Basal disc more or less developed, terminal disc usually well developed, which often forms large round discs covering the whole apical side; primary spines rather stout, not curved, with fairly developed cortical hair more or less like meshwork; secondary spines with straightcut end, moderately long. Goniocidaris (Aspidocidaris) alba Mortensen, 1928. Japan. Goniocidaris (Aspidocidaris) australiae Mortensen, 1928. Southern Australia. Goniocidaris (Aspidocidaris) clypeata Döderlein, 1885. Japan to Philippines. Goniocidaris (Aspidocidaris) crassa Mortensen, 1928. Philippines. Goniocidaris (Aspidocidaris) fimbriata de Meijere, 1904. Malayan Archipelago. Goniocidaris (Aspidocidaris) indica Mortensen, 1939. Indian Ocean. Goniocidaris (Aspidocidaris) parasol H. B. Fell, 1958. New Zealand. Goniocidaris (Aspidocidaris) sibogae Mortensen, 1928. Philippines.

Subgenus Cyrtocidaris Mortensen, 1928 Basal and terminal discs more or less well developed; primary spines usually long and slender, often curved, with a fairly distinct coat of cortical hair; oral primaries very long, thin, and smooth; secondary spines long and slender, distally pointed. Goniocidaris (Cyrtocidaris) tenuispina Mortensen, 1927. Philippines. Subgenus Discocidaris Döderlein, 1885 Basal discs strongly developed, often repeated several times along the shaft of ambital primaries; terminal disc more or less developed; hairy coat very conspicuous; secondary spines flattened, sometimes thorny at base: Goniocidaris (Discocidaris) mikado Döderlein, 1885. Japan. Goniocidaris (Discocidaris) peltata Mortensen, 1927. Malayan Archipelago and Philippines to New Zealand. Subgenus Goniocidaris Desor in L. Agassiz & Desor, 1846 No basal disc, terminal disc usually not conspicuous; thorns on primary spines coarsely thorny to almost lacking, cortical hair moderately developed; secondary spines somewhat thickened: Goniocidaris (Goniocidaris) tubaria Lamarck, 1816. Southern Australia from Brisbane on the east coast to Perth, Western Australia, rarely Tasmania. Goniocidaris (Goniocidaris) umbraculum Hutton, 1872. New Zealand. Subgenus Petalocidaris Mortensen, 1903 Basal and terminal discs more or less developed; primary spines with coarse thorns, often banded; hairy coat more or less developed; secondary spines flattened and more or less thorny at base. Goniocidaris (Petalocidaris) biserialis Döderlein, 1885. Japan to China Sea. Goniocidaris (Petalocidaris) florigera A. Agassiz, 1879. Malayan Archipelago and Philippines. Goniocidaris (Petalocidaris) spinosa Mortensen, 1928. Indonesia. Goniocidaris corona Baker, 1968: New Zealand. Goniocidaris magi Pawson, 1964. Northern New Zealand. The following descriptions are listed alphabetically according to the species names. Goniocidaris (A.) alba Mortensen, 1928 Main characteristics of genus and subgenus. Holotype 25 mm in diameter. Interambulacra: Narrow naked median line and shallow grooves; scrobicular tubercles only slightly larger than marginal ones in ambulacra; peristome small.



Primary spines: Rather robust, set with a basal disc, becoming thorns distally; adapical primaries with large, eccentric terminal discs with smooth or very finely serrated edges; oral primaries very smooth and shining, proximally with obsolete lateral thorns. Secondary spines: Scrobiculars flattened, 3  mm long; marginals narrower, 2 mm long; small spines slender with distinct ridges; other secondaries not appressed. Color: Test and primary spines white, secondaries on the apical side with a faint yellowish tint. Distribution: Japan. Remark: Rowe & Hoggett (1985) regard Goniocidaris alba and G. australiae (see below) synonymous with G. sibogae. Mortensen (1928) has described these three nominal species simultaneously separating them by the extent of the naked interambulacral median areas, by the shape of the primary spines and by the degree of the green color on the naked test. Having numerous specimens on hand, Rowe & Hoggett (1985) could recognize that transitional individuals fit variously into the original descriptions of the three species. Goniocidaris (A.) australiae Mortensen, 1928 (Fig. 4.47 A) Characteristics of the genus and subgenus (see remark above). Distribution: Southern Australia. Goniocidaris (P.) balinensis Mortensen, 1932 (Fig. 4.47 B) Test: Maximum recorded test diameter 30 mm. Apical system: Less than half the test diameter; ocular plates insert; genital plates set with 2 to 3 larger tubercles on the inner part and several very small tubercles; distinct naked border on both genital and ocular plates; periproctal plates with one larger tubercle each. Ambulacra: Sinuate, interporiferous zone sloping gently to the midline; marginal tubercles widely separated, median space covered with small irregularly arranged tubercles; horizontal sutures distinctly grooved, median suture naked, and somewhat sunken. Interambulacra: Areoles deep with radiating striation; inner zone narrow, circle of extrascrobicular tubercles half the size of scrobiculars, inner space filled with some very small tubercles leaving no naked median line, only a small but distinct groove at the inner part of the horizontal suture. Primary spines: With well-developed basal disc, shaft set with more or less numerous coarse thorns, not arranged in longitudinal rows; not tapering toward the point; apical spines may widened to a star-shaped crown; surface of shaft covered with a coat of rather long, fine, and somewhat thorny hairs; oral primaries with coarse serrations.

4.1.1 Order: Cidaroida Claus, 1880 

 95

Secondary spines: Scrobiculars 3 mm long, scarcely narrowing to the straight-cut end, basally with small thorns; marginal spines 2  mm long, very narrow, and likewise with thorns basally. Color: The spines have a faint greenish tint, with an indication of darker bands on the ambital primaries. The denuded test is white with conspicuous green apical plates, more distinct in smaller specimen. The tube feet are tipped with reddish brown. Occurrence: The two specimens in Copenhagen were dredged in the Bali Sea, Indonesia. Depth 150 m. Goniocidaris (P.) biserialis (Döderlein, 1885) (Fig. 4.47 C–E) Test: Maximum recorded test diameter 34 mm. Apical system: Ocular plates to a various degree exsert; tubercles scarce, mainly concentrated around the genital pores and as an irregular row along the inner edge of the genital plates; periproct small, sometimes elevated. Ambulacra: Distinctly sinuate; marginal tubercles small and nearly contiguous, inner space with one to three (depending on size) fairly regular series of three mince tubercles, leaving no naked median area, sloping toward the midline; horizontal sutures sharply and narrowly incised. Interambulacra: Areoles rather small as there is space for smaller tubercles between each two adjoining scrobicular circles, subambital areoles slightly transverse oval; scrobicular tubercles more or less prominent, encircled by alternating ones of half that size, median zone wholly covered with very small tubercles of uniform size, arranged in horizontal ridges, no naked space left; horizontal sutures well marked with slight deepening toward the midline. Primary spines: Vary in length from less than to 1.5 times the test diameter often ending in a small crown; shaft set with very strong, slightly forward directed thorns, arranged more or less in two lateral series; at the base they may coalesce forming a disc; surface of the shaft and of large thorns covered by long, smooth, fine cortical hairs with bifid ends; adapical primary spines with moderately large disc with strongly serrated margin, sometimes even whorl-shaped; oral primaries flattened and with finely serrated ridges. Secondary spines: Scrobiculars about 3 mm long, flattened, hardly tapering to a straight-cut end; marginal spines narrower; small spines look like simple pointed stumps. Color: Test and spines are generally light brown; well-­ preserved primaries (not overgrown) are dark green brown with white bands, the scrobicular spines are light brown with a dark green or olive green base. The denuded test is white or a light brown, the apical plates darker brown.

96 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

C

D

E

Fig. 4.47: (A) Goniocidaris australiae. Aboral side with spines, diameter of test 12 mm; Tasmania. ZMUC. The adapical spines end distally in distinct terminal discs. (B) Goniocidaris balinensis. Aboral side with spines, test diameter 24 mm; Bali Sea, Indonesia. ZMUC ECH 559. (C–E) Goniocidaris biserialis. Aboral side with spines, diameter of test 30 mm; Chi-lung, northeast Taiwan. The very coarse thorns are arranged more or less in two lateral rows. (D) Aboral side of test, diameter 32 mm; northeast Taiwan. (E) Side view of test: there is no depressed, naked midline, but sharply incised horizontal sutures forming slits at the triple junctions.

Distribution: This species is recorded from Sagami Bay, Japan, and the Korea Strait to the East China Sea and Taiwan. Bathymetric range about 100 to 500 m. Goniocidaris (A.) clypeata Döderlein, 1885 (Fig. 4.48) Apical system: A few scattered tubercles, increasing in size and number near the anus.

Ambulacra: Broad interporiferous zone, 2–3 times the width of pore zone; inside of regular row of marginal ­tubercles one or two smaller tubercles per plate; median zone naked and sunken, horizontal sutures also depressed. Interambulacra: Areoles distinctly depressed, rather small and round, well separated except the lower most; scrobicular tubercles well differentiated,

4.1.1 Order: Cidaroida Claus, 1880 



A

B

 97

C

D

Fig. 4.48: Goniocidaris clypeata. Side view of test, diameter 23 mm; Philippines. The median areas in ambulacra and interambulacra are depressed with conspicuous pits in the horizontal sutures. There are also pits at the outer edge of the interambulacral plates. (B) Aboral side of test. (C) Aboral side with spines, diameter of test 19 mm; Balut Island, Philippines. The ambital primary spines are long and pointed with basal spurs. Toward the apex, the shape of the primaries changes abruptly: the distal end is formed like a cup the shaft becoming gradually shorter. (D) Aboral side with spines, diameter 45 mm; Sagami Bay, Japan. ZMUC. The edge of the terminal discs may be smooth (see C) or strongly serrated (D).

extrascrobicular tubercles small; median zone like a bare, depressed zigzag band, more or less extending into horizontal sutures. Primary spines: Around ambitus slender, the shaft set with basal spurs or several broad thorns more or less

forming discs, adapical spines shorter with large terminal widenings, forming smooth cups or serrated discs. Secondaries spines: Scrobiculars spines flattened; marginals very slender, flattened, other secondaries very small and ridged.

98 

 4.1 Subclass Cidaroidea Smith, 1984

Color: Test and secondary spines yellowish white, apical primary spines with pink or red tint on the “cups”, other primaries white. Distribution: This species is known from Japan to the ­Philippines at depths of about 100 to 700 m. Goniocidaris corona Baker, 1968 (Fig. 4.49) Test: Diameter up to 20 mm. Apical system: Uniformly tuberculated, ocular plates exsert, sometimes with prolongated periproctal plates. Ambulacra: Almost straight; interporiferous zone about twice the width of 1 pore zone; marginal tubercles regular, two small tubercles inside the marginal ones; median part more or less naked, slightly sunken; horizontal sutures with more or less distinct pits. Interambulacra: Areoles transversely oval and separated; scrobicular tubercles forming a more or less complete ring; median area covered by small tubercles, but slightly sunken, deeper pits at horizontal sutures. Peristome: Remarkably small (compared with G. parasol). Primary spines: Stout, more or less thorny, flaring into a distinct crown; around the apical disc smooth with fine serrations, over the oral side flattened, blunt, outer side serrated or irregularly ridged. Secondaries: Scrobicular spines flattened, distal ends short-cut; marginal spines in ambulacra about same size as scrobiculars, other secondaries short and narrow. Color: In life, the test is light brown as are the primary spines or tending to pink. The scrobicular spines are dark brown. The bare test is cream with green median areas in ambulacra and interambulacra. Biology: Small juveniles with long spines were found on the apical disc between the upper primary spines (Baker 1968). It is likely that this species is brood-protecting in the same way as in Goniocidaris umbraculum. Remarks: In contrast to other species of Goniocidaris, G. corona has developed stout primary spines with more or less conspicuous thorns. The adapical ones are of the same shape. Goniocidaris magi Pawson, 1964, endemic to New Zealand and living at deeper water, differs from G. corona in having interporiferous zones that reach 4 times the width of a pore zone. Distribution: This species is endemic to New Zealand, known rarely from the littoral down to 132 m. Goniocidaris (A.) crassa Mortensen, 1928 (Fig. 4.50 A) Test: Maximum recorded diameter of test of 24 mm. Primary spines: Very thorny, the ambital spines with basal discs at the inner (adapical) side of the shaft, no ­terminal discs.

Remark: Rowe & Hoggett (1985) think Goniocidaris crassa and G. fimbriata being synonymous. Mortensen (1928) described Goniocidaris crassa as having no terminal disc on the adapical primary spines. He supposed these specimens of a test diameter of 19–24  mm to be juveniles, on which the terminal discs would develop later in age. Goniocidaris fimbriata was described by de Meijere (1904) on the basis of two specimens of 10 and 11 mm having likewise no terminal discs. Mortensen (1928) introduced two other specimens of 13 and 15 mm as conspecific but having well developed terminal discs. It seems rather improbable that such large discs develop within a growth of 3–5 mm. So the question arises if the specimens of G. fimbriata sensu Mortensen are actually G. fimbriata sensu de Meijere? Rowe & Hoggett (1985) examined 40 specimens of G. alba, G. australiae, and G. sibogae and think them conspecific. They report that the terminal discs seem to develop only at a test diameter of more than 8 mm at first as small slides on a long shaft. Later in growth, the shaft decrease in length while the disc itself becomes larger. Goniocidaris (A.) fimbriata de Meijere, 1904 (Fig. 4.50 B) Primary spines: Rather thick and stout, tapering to the point, which itself is widened into a larger or smaller crown; on the basal part, there is a fairly well-developed disc, the shaft is otherwise set with rather long, outward curved, flattened, or serrated thorns distributed densely and more or less on ridges; on the underside of the spines, the ornamentation is less distinct, but rather ridged; shaft surface covered with a close coat of cortical hair; adapical spines with broad terminal disc (see remark above), which may be centrally set with some coarse hairs; collar very short. Oral primaries: Slender and coarsely serrated. Secondary spines: Scrobiculars ca. 2 mm long, flattened, hardly narrowing toward the straight-cut end, marginal spines of similar shape, but narrower. Color: Primary and secondary spines on apical side with pink tint, the denuded test shows a faint yellow green tinge. Distribution: Goniocidaris fimbriata is recorded from the Malayan Archipelago at depths of about 300 to 500 m. Goniocidaris (P.) florigera A. Agassiz, 1879 (Fig. 4.50 C, D) Test: Rather high, more or less flattened above. Apical system: All ocular plates insert; all plates covered by small uniform tubercles, a few larger tubercles are scattered mainly around the anal opening.

4.1.1 Order: Cidaroida Claus, 1880 



A

 99

B

C D

Fig. 4.49: Goniocidaris corona. (A) Primary spines: they are equipped with thorns, more or less eroded; the adapical one is flared with thorns at the tip. Scale: 1 mm. Redrawn after Baker 1968. (B) Side view of female, diameter with spines 35 mm; Northland, New Zealand. The spines are short and stout, their thorns being eroded and overgrown by incrusting organisms. (C) Aboral side with spines: some juveniles hide between the spines (see arrows). (D) Aboral side of female test, diameter 26 mm; Chatham Rise, off New Zealand. The gonopores are strongly enlarged.

Ambulacra: Marginal tubercles not contiguous, inner space covered with several, irregularly arranged small tubercles, the vertical suture being hardly visible; horizontal sutures deepened forming distinct grooves. Interambulacra: Extrascrobicular area densely covered by small tubercles arranged in horizontal rows and separated by furrows; no vertical naked or deepened line, but distinct horizontal grooves.

Primary spines: Very long, 2–3 times the test diameter, usually cylindrical and ending in a small crown, the shaft set with coarse thorns, rather distant from each other, basally coalesced to a deeply indented disc; adapical primaries with irregular terminal disc; all well-preserved spines covered by cortical hair; oral primaries with lateral serrations and some small thorns.

100 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

D C

Fig. 4.50: (A) Goniocidaris crassa. Aboral side with some remaining spines, diameter of test 22 mm; Celebes Sea. ZMUC ECH 404. The ambital spines are set with long and sharp thorns. (B) Goniocidaris fimbriata. Aboral side with spines, test diameter 15 mm; Kei Island, Indonesia. ZMUC. (C, D) Goniocidaris florigera. Aboral side of female. Test diameter 26 mm; Cebu, Philippines. The large gonopores are positioned subcentrally in the genital plates. (D) Aboral side with spines, diameter of test 24 mm; Cebu, Philippines. The discs at the adapical primary spines show terminal branches.

Secondary spines: Scrobiculars nearly rectangular and straight cut, with thorns laterally and at the base, marginals more slender. Color: Test and secondary spines are whitish; well-­ p reserved primaries show pink spots on the

upper side, giving it a banded appearance when viewed from above. On denuded tests, the apical system has a greenish tint continuing onto the ambulacra. Distribution: Malayan Archipelago and Philippines.

4.1.1 Order: Cidaroida Claus, 1880 



Goniocidaris (G.) impressa Koehler, 1926 (Fig. 4.51 A) Test: Maximum diameter more than 50 mm. Apical system: Variable in size and in the arrangement of the ocular plates, plates evenly covered with small tubercles of rather uniform size; gonopores larger in females than in males. Ambulacra: Slightly sinuous, marginal series of tubercles very regular, contiguous, the median space sunken, with depressed horizontal sutures in ladder-like shape,

A

 101

covered by very small tubercles, but may also be more or less naked; pore zone half the width of interporiferous zone. Interambulacra: 8–10 plates in one column; areoles rather small, more or less sunken, transverse oval and well separated; scrobicular tubercles fairly conspicuous, surrounded by alternating smaller ones; extending more or less into the median zones, and forming correspondingly isolated sunken pits or continuous bare zones.

B

D

C

E

Fig. 4.51: (A) Goniocidaris impressa. (A) Side view, diameter with spines 89 mm; Bicheno, Tasmania, Australia. The aboral spines show a trumpet-like end. (B, C) Goniocidaris indica. (B) Side view of test, diameter 21.5 mm; Pemba Island, Tanzania. ZMUC ECH 158. There are only small pits at the median triple junctions in the interambulacra, the vertical suture is hardly depressed and not at all naked. (C) Close-up of aboral side with spines, test diameter 18 mm; Maldives. ZMUC. (D, E) Goniocidaris magi. (D) (1) Oral primary spine. Scale: 2 mm. (2) Adapical primary spine. Scale: 5 mm. Redrawn after Pawson 1964. (E) Aboral side with spines. Sketch after a photo in McKnight 1969.

102 

 4.1 Subclass Cidaroidea Smith, 1984

Peristome: Generally somewhat smaller than the apical system. Primary spines: Rather short, covered with more or less thick thorns, cylindrical, with a slightly widened crown at the tip; the adapical spines may be trumpet-shaped or at least with a flaring tip. Secondary spines: Flattened, scrobicular spines larger than marginals; small spines club-shaped. Color: The primary spines are usually white, the secondaries cream to lavender. The median lines may be slightly darker. The bare test often shows a greenish cast over the apical system. Biology: This species shows sexual dimorphism: the females have much larger gonopores than the males. It is very likely that the young develop directly from the egg being protected on the test of the female. Distribution: Goniocidaris impressa occurs in Australia, from South Australia to Wilson’s Promontory, Victoria, and around Tasmania from 9- to 160-m depth. Remarks: Goniocidaris impressa differs from Goniocidaris tubaria by the generally less thorny primary spines and especially by the club-shaped miliary spines. The bare test is distinguished by the even tuberculation of the genital plates and by the ladder-shaped pits in the ambulacra. Goniocidaris (A.) indica Mortensen, 1939 (Fig. 4.51 B, C) Test: The largest specimen described by Mortensen measured 25 mm in diameter. Apical system: Tuberculation not very dense. Ambulacra: Marginal tubercles not contiguous, inner space set with 4–6 small tubercles; pits along the median suture. Interambulacra: Extrascrobicular space small and dense, leaving no naked midline; median end of horizontal sutures deepened so as to form distinct pits. Primary spines: In length, 1.5–2 times the diameter of test; gradually tapering to a point; shaft set with low thorns being almost hidden in cortical hair; basal discs well developed mainly on the adapical side of the shaft; uppermost spines widened into a broad, eccentric terminal disc; oral primaries slender, slightly curved, and with only faint lateral serrations. Secondary spines: Scrobiculars about 2 mm long, rather thick, smooth, nearly rectangular; marginal spines similar, but more slender and shorter. Color: In general, straw yellow with white primary spines. Distribution: Reported from the Indian Ocean: off the Maldives, Tanzania, and presumably off East London, South Africa (A. M. Clark & Courtman-Stock 1976). Bathymetric range 162 to 640 m.

Goniocidaris magi Pawson, 1964 (Fig. 4.51 D, E) Main characteristics of the genus and subgenus. Small form. Ambulacra: With oblique pore pairs. Naked median areas in ambulacra and interambulacra conspicuously broad and sunken. Primary spines: Stout and short or more slender and cylindrical reaching 130 % of diameter of test; no basal and no terminal discs; shaft of upper spines with very fine spinelets and distal widening or faint crown; shaft may be set with coarse, blunt bumps or a pair of spurs; scrobicular spines elongated slightly widening toward the flat distal end. Color: Yellow brown to yellow green, scrobicular spines creamy white, primary spines white. Distribution: This species seems to be confined to the North Island of New Zealand. Bathymetric range of holotype 135 m. Goniocidaris (D.) mikado Döderlein, 1885 (Fig. 4.52 A, B) Test: Relatively high, flattened above, not so below, rather fragile. Maximum recorded test diameter 24 mm. Apical system: All ocular plates insert, all plates relatively sparsely covered with small heterogeneous tubercles. Ambulacra: Marginal tubercles in a regular series, not much smaller than scrobicular tubercles, 3–5 much smaller inner tubercles per plate of uniform size, leaving no naked median space, horizontal sutures only slightly sunken. Interambulacra: 6–7 plates per column; prominent scrobicular tubercles; extrascrobicular area densely covered by small tubercles of uniform size; grooves in horizontal sutures inconspicuous, at most visible below the ambitus. Primary spines: In length, 1–1.5 times the diameter of test, adapical side of shaft set with numerous coarse and irregularly arranged thorns, often they may be biserially; usually with a large, flat, and serrated basal disc; adapical spines extraordinarily variable in shape from slender and simply pointed to short and set with a large, more or less fenestrated terminal disc; oral primaries serrated; all well-preserved spines are covered with a dense coat of fine hair. Secondary spines: Scrobiculars rather thick, slightly tapering to the rounded point; marginal spines slightly club-shaped, small spines granular. Color: Usually, the test and spines are yellowish white. The apical primary spines may be tinged with pink or yellow. Distribution: Goniocidaris mikado is confined to Japanese waters from Sagami Bay to Goto Island. Bathymetric range about 100 to 700 m.

4.1.1 Order: Cidaroida Claus, 1880 



A

B

D

 103

C

E

F

Fig. 4.52: (A, B) Goniocidaris mikado. (A) Aboral side with spines, test diameter about 19 mm; Sagami Bay, Japan. ZMUC. (B) Close-up of spines. The surface of the primary spines is covered with long, fine cortical hairs. (C) Goniocidaris indica. Aboral side with a few remaining spines, test diameter 21.5 mm; Pemba Island, Tanzania. The spines are set with a basal disc and fine thorns. (D) Goniocidaris parasol. Aboral side with spines, test diameter 23 mm; Great Barrier Island, New Zealand. The aboral spines have basal and terminal discs. (E, F) Goniocidaris peltata. (E) Side view of test. Diameter 22 mm; Bali, Indonesia. (F) Terminal disc of holotype. Maximum length 11 mm. ZMUC. The upper right side is directed toward the center.

Goniocidaris (A.) parasol Fell, 1958 (Fig. 4.52 D) Ambulacra: Median area naked and sunken, forming a conspicuous vertical furrow of same width from plate to plate, not in a zigzag course, but slightly sinuous. Interambulacra: Broad naked median zone with incised horizontal and vertical sutures.

Primary spines: Cylindrical with basal discs developed only on the adapical side of the spine; shaft set with a few small thorns, spines below the ambitus rather ridged, becoming a small distal crown, on spines above the ambitus forming large, smooth, more or less eccentric horizontal discs; shaft may be variously long or short.

104 

 4.1 Subclass Cidaroidea Smith, 1984

Oral primaries: More or less spear-shaped, sometimes laterally serrated. Color: Living specimens have light purple to mauve primary spines, secondaries are rich red brown. Distribution: Goniocidaris parasol is recorded off both islands of New Zealand in deeper water at about 200 to 1,000 m. Remark: Rowe & Hoggett (1985) reported young specimens having relatively long adapical spines with small terminal discs. In adult specimens, the spines become relatively shorter and the disc larger. This observation does not seem to be applicable in my specimen (Fig. 4.52 D), as here the adapical primary spines show a large disc on a long shaft and the youngest spines around the apical disc have small discs also on a relatively long shaft. Goniocidaris (D.) peltata Mortensen, 1927 (Fig. 4.52 E, F) Test: High, flattened above but not so much below. Apical system: Regularly but not densely covered by small tubercles of fairly uniform size, sometimes series of larger tubercles along inner edge of genitals; oculars insert or exsert. Ambulacra: Distinctly sinuate, regular marginal tubercles, median space set with much smaller inner tubercles, no naked median zone; horizontal sutures with distinct grooves. Interambulacra: Areoles round, below the ambitus slightly transverse oval; scrobicular tubercles a little larger than marginals; extrascrobicular space closely filled by small more or less irregular tubercles, median part of horizontal sutures with small, more or less distinct grooves. Primary spines: 2.5–3.5 times the test diameter, curved downward; basal discs around the shaft, which is otherwise closely set with straight thorns, forming more or less repetitions of the basal disc; adoral side of spines almost smooth; adapical primaries end distally in large terminal discs the margins coarsely serrated or branched; well-preserved spines covered by a bristling coat of cortical hair. Secondary spines: Almost parallel sides and straight-cut ends, marginal ones much narrower than scrobiculars; small spines very short, conical. Color: Test and primary spines white, secondary spines may be yellow. Distribution: Goniocidaris peltata is known in the Malayan Archipelago and the Philippines. Goniocidaris (A.) sibogae Mortensen, 1928 (Fig. 4.53 A) Likely to be synonymous with G. alba and G. australiae. Test: Maximum recorded test diameter 22 mm. Interambulacra: Scrobicular tubercles only slightly larger than marginal tubercles, extrascrobiculars gra-

dually decreasing in size toward the midline, forming horizontal ridges; there is no naked median band, only the median part of the horizontal sutures is depressed as small, but distinct grooves. Primary spines: Slender and cylindrical, at the ambitus about 1.5 of test diameter; no crowns developed; set at the base with discs being more widened toward the apical side; shaft usually with irregularly distributed small, but sharp thorns; terminal discs may be serrated or not; surface of shaft covered by a close coat of low cortical hair; oral primaries slender with serrated edges. Secondary spines: Flattened, with parallel sides and straight-cut ends; marginal spines shorter and narrower than scrobiculars. Color: Test and secondary spines of a slight pinkish tint, juveniles sometimes faintly greenish, primaries and naked test white. Distribution: Goniocidaris sibogae is known from the Philippines at deeper water. Remark: Rowe & Hoggett (1986) synonymized G. (A.) sibogae with G. (A.) alba and G. (A.) australiae. They described the changes for the entire group during growth from juveniles with a small faintly greenish test and small terminal disc on a relatively long shaft to adults with white test and relatively larger terminal disc on a shorter shaft. Goniocidaris (P.) spinosa Mortensen, 1928 (Fig. 4.53 B, C) Apical system: Rather bare, only one or two larger tubercles per plate; ocular plates narrowly insert. Ambulacra: Strongly sinuate; regular series of marginal tubercles, inner space with irregularly arranged much smaller ones; grooves in horizontal sutures distinctly depressed, connected along the median vertical suture. Interambulacra: Scrobicular tubercles twice the size of marginal tubercles; extrascrobicular zone covered with small tubercles leaving no naked median line; small, but distinct pits at the inner end of the horizontal sutures. Primary spines: At the ambitus, about twice the diameter of test, tapering toward the point; basal disc at the adapical side well developed, shaft otherwise set with coarse thorns often having two tips; the five uppermost spines short ending in a more or less serrated disc with a point directed toward the center; surface of shaft covered with rather coarse cortical hairs; oral primaries straight and unusually long with coarse thorns on the aboral (outer) side. Secondary spines: Scrobicular spines about 2 mm long, moderately appressed; gently tapering toward the straightcut end, distinctly excavated in their whole length, small basal thorns; marginal spines narrow and flattened.

4.1.1 Order: Cidaroida Claus, 1880 



A

C

 105

B

D

Fig. 4.53: (A) Goniocidaris sibogae. Oblique view with spines, diameter of test 20 mm; southern Sulu Sea. ZMUC ECH 405. (B, C) Goniocidaris spinosa. Oral side with spines, diameter of test about 20 mm; Amboina Bight, Indonesia. ZMUC ECH 50. The oral primaries are very long and slender and coarsely thorny. (C) Aboral side with spines. Diameter over spines 85 mm; Mactan Island, Philippines (photo by Willi Clarenbach). The discs of the adapical primary spines are pointed toward the center, the edges being strongly indented. (D) Goniocidaris tenuispina. Oral side with spines, test diameter 21 mm. ZMUC ECH 469. The adoral primary spines are very long, thin, and smooth.

106 

 4.1 Subclass Cidaroidea Smith, 1984

Color: Test and secondary spines yellow, primary spines on the upper side of the test with purple red spots, confined to the adapical side of the shaft. The oral primaries are also red. The scrobicular spines show sometimes a dark green base. On the cleaned test, the apical system, especially the ocular plates and the outer part of the periproctal plates, may be a dark green brown, which may faintly extend onto the ambulacra. Distribution: Malayan Archipelago and Philippines, deeper water. Goniocidaris (C.) tenuispina Mortensen, 1927 (Fig. 4.33 D) This species is characterized by its very long and smooth oral primary spines. Main characteristics of the genus. Test: Maximum recorded test diameter 29 mm. Apical system: Ocular plates usually just insert; plates sparsely covered with small tubercles of uniform size; rather broad bare edges on genital plates. Ambulacra: Rather sinuous; marginal tubercles small, not at all contiguous, inner space set with several very small tubercles, naked, depressed zigzag line along the median suture. Interambulacra: Naked median line rather narrow. Primary spines: Very long and slender, 2–3 times the horizontal diameter, tapering to a rather fine point; basal disc indistinct, shaft otherwise set with rather sharp thorns not at all regularly arranged; surface covered by a dense meshwork of cortical hair; adapical primaries generally short with terminal disc deeply indented, sometimes even looking like a flower; oral primaries long, very slender, totally smooth, and distinctly curved. Scrobicular spines: Long, about 3 mm, slender with rounded point, marginal spines 2 mm long and also very narrow. Color: Test and secondary spines yellow white to light pink, denuded test white. Distribution: Goniocidaris tenuispina is known in the Philippines. Recorded depth 570 to 1,411 m. Goniocidaris (G.) tubaria Lamarck, 1816 (Fig. 4.45, 4.54 A–C) Test: Flattened above and below, diameter up to 60 mm. Apical system: Variable in size and in the arrangement of the terminal plates; they may be all insert, partly exsert, or even all exsert; genital plates, except for the madreporite, have tubercles in two patches, one surrounding the pore and one at the inner edge; gonopores of females larger than those of males. Ambulacra: Slightly sinuate, marginal series of tubercles very regular, contiguous, the median space bare and

sunken; pore zone half the width of interporiferous zone, pores rather small. Interambulacra: With 8–10 or even 13 plates in one column; areoles rather small, more or less sunken, transverse oval and well separated; scrobicular tubercles fairly conspicuous, surrounded by alternating smaller ones; the remaining space of the plate naked, sunken and continuing as a deep zigzag groove along the median suture, often also at the outer sides of the plates. Peristome: Generally somewhat smaller than the apical system. Primary spines: Short and thick; with coarse, sharp thorns and flaring tips, adapical spines with several sharp distal points or at least with a flaring tip. Secondary spines: Flattened, scrobiculars larger than ambulacral marginals; miliary spines very small, slender, and distally pointed or flattened. Color: The primary spines are usually whitish, thorns brown; they may also be dark violet or even nearly black; the secondaries red to lilac, often with green tips. The median lines or even the whole space outside the areoles may be dark purplish. The specimens in the western part of Australia are generally paler in color, being cream or rather yellowish. Biology: This species is sexually dimorphic, the females having much larger gonopores than the males. Mortensen (1927) reported large eggs of 0.5 mm diameter. The young develop directly being protected on the test of the female (observed by Baker 1984; for details of development see Goniocidaris umbraculum). Remarks: Goniocidaris tubaria differs from Goniocidaris impressa, with which it partially co-occurs, by the patchy tuberculation of the genital plates and by the shape of the miliary spines: in G. tubaria, they are slender and pointed; in G. impressa, club-shaped. The denuded test has continuous, bare areas in contrast to G. impressa with more isolated pits. Distribution: Goniocidaris tubaria is known around the southern part of Australia, from Brisbane on the east coast to Perth in Western Australia and rarely from the northern part of Tasmania, living from the littoral zone to a depth of about 650 m. Goniocidaris umbraculum Hutton, 1872 (Fig. 4.54 D, E) Test: The diameter may reach more than 50 mm. Spines: This species of Goniocidaris differs from the others by the shape of its primary spines. Ambital spines with a pair of lateral thorns or spurs at the base, adapical primaries quite short, distally widened into a flat or slightly concave, rounded, eccentric disc with a diameter up to 5–6 mm; approximately 0.5 to 0.75 of test diameter

4.1.1 Order: Cidaroida Claus, 1880 



A

 107

B

C

D

E

Fig. 4.54: (A–C) Goniocidaris tubaria. (A) Side view of test, diameter 20 mm; Victoria, southern Australia. Only the grooves in the horizontal sutures of the interambulacra are developed, the naked bands along the midlines are totally lacking. (B) Aboral side with spines, diameter over spines 98 mm; Sydney Harbour, New South Wales, Australia. (C) Close-up of ambulacra, and interambulacra. Diameter of test 41 mm; off Sydney, New South Wales, Australia. Scale: 5 mm. (D, E) Goniocidaris umbraculum. (D) Oblique view with spines. diameter of test 15.5 mm; New Zealand. The spines are short and stout, the adoral ones ending in a small disc. (E) Side view of test, diameter 20 mm; Green Bay, New Zealand. The naked bands in the ambulacra and interambulacra are very conspicuous.

long; oral primaries scarcely curved, slightly flattened, and serrated. The bare test is distinguished by its naked interporiferous zone, which is about twice the width of 1 pore zone. Color: Primary spines are whitish, at the base with a pinkish tint; secondaries may be reddish brown. The bare test is tinted with green, especially around the apical system and the upper part of the interambulacra.

Biology: Development of the juveniles: The large, yolky eggs are released from the gonopores of the female. Presumably, they are fertilized while they are transported from the upper to the oral side. The tube feet and pedicellariae manipulate them under a roof of ambulacral spines, because the eggs are highly buoyant. It takes several hours to bring the 50–60 eggs round the test. They are accumulated at the sunken peristomial membrane, the buoyancy being now an advantage, and the oral spines cover the

108 

 4.1 Subclass Cidaroidea Smith, 1984

brood. The female burrows into very coarse sediment to hide the developing juveniles, not feeding for about six weeks. Obviously, the movement of the lantern may stir the embryos or let them swim up. The juveniles develop directly from the eggs to small adults without any larval stage or metamorphosis. During this interval, they do not feed, but are nourished by the yolk in the eggs, later in their guts. After about 50  days, they are able to climb with their first thorny spinelets and tube feet through the spines of the mother to the upper side of the test, where they hide below the discs of the adapical spines. Spines, podia, and pedicellariae continue to grow, and about 4 months after fertilization, the juveniles leave the mother, being able to feed actively by themselves. It is very likely that in G. corona and G. parasol, which are also known to shelter their young on the peristome and between their aboral spines, the juveniles are grown in a similar way. Distribution: Goniocidaris umbraculum is endemic to New Zealand at 60- to 550-m depth. It lives off the eastern coasts. Remarks: Goniocidaris umbraculum is very similar to Goniocidaris corona; the two species differing only in the shape of their primary spines. In the former, they are equipped with spurs or basal discs on the aboral side; in the latter, they are short and stout. The bare tests are indistinguishable. Genus Ogmocidaris Mortensen, 1921 The monospecific genus is distinguished from the other Goniocidarids by the lack of discs or flanges on the primary spines. Ogmocidaris benhami Mortensen, 1921 (Fig. 4.55) Test: Low, flattened above and below; test diameter up to 25 mm. Apical system: About half the test diameter; plates densely tuberculated. Ambulacra: Narrow; small oblique pore pairs. Interambulacra: 6–7 plates in a column; areoles deeply depressed; scrobicular tubercles differentiated, surrounding space covered in smaller tubercles, narrow, naked median line, with distinct pits at triple suture junctions. Peristome: Smaller than apical disc, with only 5 or 6 ambulacral plates in a column. Spines: Primaries with very short collar and neck, shaft finely granulated and set with fine hair; oral primary spines flattened and with serrated edges; secondary spines slender. Color: The primary spines are pale pink, the base is darker. The test is creamy white to pale brown.

Distribution: This species is known from the North Island of New Zealand and the Chatham Rise, living between ca. 200 and 800 m. Pierrat et al. (2012) reported it also from South New Zealand and the Auckland and Campbell Islands. Genus Psilocidaris Mortensen, 1927 This genus differs from Goniocidaris and the other Goniocidarinae in having very long primary spines and conspicuously few ambulacral and interradial plates on the small peristome. The genus is monospecific. Psilocidaris echinulata Mortensen, 1927 (Fig. 4.56 A, B) Test: Low, gently vaulted above, flattened below, distinctly sunken toward the peristome; outline circular. Apical system: Large, more than half the test diameter, somewhat elevated; ocular plates widely exsert; madreporite not enlarged; periproct relatively small; all plates densely covered by small tubercles of uniform size; there is only a narrow bare zone along the inner edge of the genital plates; gonopores in females larger than in males. Ambulacra: Sinuate, interporiferous zone twice the width of a pore zone; marginal tubercles in a regular row, rather small and not contiguous; single inner tubercle half as large; forming in the whole interporiferous zone, four regular vertical series; only a narrow naked sunken median line is left, no distinct horizontal grooves; pore zone distinctly sunken. Interambulacra: With rather large, slightly deepened areoles; well separated, even the lowermost are almost circular; boss small, no crenulation, but fairly distinct radiating furrows in the areole; circle of scrobicular tubercles not much differentiated being only a little larger than marginal tubercles; extrascrobicular space only about a third the width of an areole, filled with very small tubercles of uniform size, leaving a conspicuous naked, sunken median line with fairly distinct horizontal grooves at the inner end. Peristome: Very small, half the size of the apical system, distinctly sunken; only 3–4 ambulacral plates per column, joining at the edge of the mouth, interradial areas very small with only 1 or 2 small plates each. Primary spines: Very long, 4 or 5 times the diameter of the test, but mostly broken; straight, very slender, gently tapering to the fine point; shaft set with small more or less erect spinules, arranged in indistinct longitudinal series, not at all ridged, and of similar size throughout the whole length; surface of shaft covered by small, simple conical cortical hairs; no indication of basal discs; apical spines of

4.1.1 Order: Cidaroida Claus, 1880 



 109

A

B

C

Fig. 4.55: Ogmocidaris benhami. (A) Aboral side with spines, diameter of test 23 mm; Bay of Plenty, New Zealand. The primary spines are long and slender being set with fine granules. (B) Denuded apical disc. (C) Side view: the interambulacral median furrow is not deep. At the triple junction of the sutures, there is a distinct pit.

full length, no terminal discs; oral primaries very slender, smooth, point slightly curved. Secondary spines: Slender and usually rather erect; scrobiculars about 3 mm long narrowing to the rounded point, marginal spines about 2 mm long and very thin. Various

forms of globiferous pedicellariae with inconspicuous end tooth. Color: The primary spines are white with a pale pink tint basally; the secondaries are yellow white. The skin of the test is of a yellow red, while the cleaned test is perfectly white.

110 

A

D

 4.1 Subclass Cidaroidea Smith, 1984

B

C

E

Fig. 4.56: (A, B) Psilocidaris echinulata. (A) Aboral side with some remaining spines, test diameter 21 mm; Sulu Sea, Philippines. ZMUC ECH 473. The length of the primary spines may reach 4–5 times the diameter of test. Generally the distal part is more or less broken. (B) Oral side with spines: the peristome is remarkably small, consisting of only a few ambulacral and interradial plates. (C, D) Rhopalocidaris gracilis. (C) Aboral side of female with remaining spines. Diameter of test 19 mm; Misaki, Japan. ZMUC. (D) Side view of test: the median zones in ambulacra and interambulacra are bare and conspicuously sunken. (E) Rhopalocidaris rosea. Aboral side with spines, diameter of test 14 mm; Sagami Bay, Japan. ZMUC ECH 291. The uppermost primary spines around the apical system are lost. Usually they are not much shorter than the ambital ones.

Distribution: This species is likely to be confined to the Philippines (Palawan and Sulu Islands), living at depths of 1,400 to 1,751 m. Genus Rhopalocidaris Mortensen, 1927 This genus differs from the other Goniocidarinae in having club-shaped secondary spines.

Test: Small, in diameter usually less than 20  mm and considerably high. Apical system: About half the test diameter; ocular plates exsert; madreporite not enlarged; all plates more or less densely tuberculated; gonopores in females larger than in males; periproctal plates rather few and large.



Ambulacra: Almost straight; pore pairs oblique; marginal tubercles and a smaller inner tubercle per plate, median zone naked and conspicuously sunken. Interambulacra: Large areoles incised; scrobicular tubercles not much differentiated, adorally coalescent areoles; extrascrobicular tubercles only on inner part of plate; median zone with broad naked sunken furrow, small horizontal pits. Peristome: Approximately as large as apical disc; interradial plates not reaching the mouth. Primary spines: In length, variable; strong thorns at the base of the shaft becoming smaller toward the distal end, which may be set with faint ribs; between the thorns, the surface of the shaft is covered with dense cortical hair; oral primaries variable. Globiferous pedicellariae: With end tooth present. Secondary spines: Club-shaped and not appressed. The genus contains three species: Rhopalocidaris gracilis Döderlein, 1885. Japan. Rhopalocidaris hirsutispina de Meijere, 1904. Indo-West Pacific. Rhopalocidaris rosea Mortensen, 1928. Japan. M. Shigei (1986) synonymized Rhopalocidaris gracilis and R. rosea. Rhopalocidaris gracilis Döderlein, 1885 (Fig. 4.56 C, D) Apical system: Sparsely tuberculated, on genital plates confined to the center; ocular plates widely exsert. Interambulacra: Areoles on the upper side separated, below the ambitus confluent and slightly transverse oval; scrobicular tubercles hardly larger than marginal tubercles, extrascrobiculars slightly smaller than scrobiculars forming a single alternating half-circle, leaving the broad median part of the plate bare and sunken, with only small tubercle here and there; horizontal sutures markedly grooved. Primary spines: Varying in length, about 1.5–2.5 the diameter of test; tapering gently into a fine point, which shows sometimes a small crown; shaft set with coarse, irregularly arranged thorns; oral primaries smooth. Secondary spines: Distinctly club-shaped and finely serrated. Color: The primary spines are white, the collar faintly pink. The test and the secondary spines are whitish to yellow red. The naked test is usually white, but may show a very faint tint of purple or green on the apical system. Distribution: This species is confined to Japanese waters. Mortensen (1928) reported depths of 180 to 700 m. Rhopalocidaris hirsutispina de Meijere, 1904 Test: Diameter hardly exceeding 14 mm.

4.1.1 Order: Cidaroida Claus, 1880 

 111

Apical system: Moderately tuberculated, a fairly broad edge of the genital plates remaining bare. Ambulacra: Conspicuously sunken median zone. Interambulacra: Small areoles; scrobicular tubercles scarcely larger than marginal tubercles; on median part of plates, one or two half circles of alternating extrascrobicular tubercles, almost as large as scrobiculars; rest of plate naked and sunken, horizontal grooves hardly marked. Peristome: Conically raised. Primary spines: In length, not more than diameter of test; tapering to a blunt point; shaft set with irregularly arranged, coarse thorns, which continue almost to the end, gradually decreasing in size; distal part of shaft with some rather prominent ridges; surface otherwise covered with a close coat of long, fine cortical hairs, which gives the spines a rather shaggy appearance, diminishing in size toward the naked distal end; oral primaries small, straight and with distinct lateral serrations. Secondary spines: Scarcely longer than 1 mm, scrobiculars and marginals of same size, club-shaped and erect. Color: Primary spines with a faint tint of pink at the base, otherwise white or light yellowish, as also the secondary spines. The naked test is white or with a trace of green on the genital plates. Distribution: The holotype from de Meijere and the specimen from Mortensen (ZMUC) came from the eastern part of the Malayan Archipelago from depths of 469 and 385 m. Remark: Mortensen (1927) established a variety R. hirsutispina var. viridis, which differs in having a green test and somewhat larger primary tubercles. The single specimen was found off northern Mindanao, Philippines. Depth 296 m. Rhopalocidaris rosea Mortensen, 1928 (Fig. 4.56 E) Very small form. Test: Rather high, slightly flattened above, oral side sloping toward the somewhat raised peristome. Apical system: Densely tuberculated but leaving conspicuous naked borders around the genital plates; periproct often slightly elevated. Ambulacra: Moderately tuberculated, more or less distinct bare margins. Interambulacra: Small, round, well-separated areoles; scrobicular tubercles slightly larger than marginal tubercles; extrascrobicular tubercles hardly smaller than scrobiculars, fairly numerous, but leaving a conspicuous, naked, sunken median band with fairly marked horizontal grooves. Primary spines: Usually slender; in length, 2–3 times the diameter of test, tapering to the often crowned distal end; shaft set with irregular coarse thorns, decreasing in size and number toward the tip; basal surface densely covered

112 

 4.1 Subclass Cidaroidea Smith, 1984

by cortical hairs; oral primaries nearly straight, set with distinct lateral serrations and thorns on the aboral side. Secondary spines: Scrobiculars about 1.5 mm long, erect, not fitting together; point only slightly widened; marginal spines of similar appearance, but more slender and shorter. The large globiferous pedicellariae are numerous and conspicuously large (according to Mortensen 1928). Color: Primary spines white, on the aboral side with more or less continuous bands of pink or rose; apical secondary spines usually green brown as also the uppermost scrobicular spines on the aboral side (Mortensen 1928 emphasized this feature as typical for this species); otherwise, they are white. On the naked test, the apical plates are conspicuously green with white edges; sometimes, the green extends onto the uppermost areoles. Distribution: This species seems to be confined to Japanese waters at a depth of about 160 to 700 m. Genus Schizocidaris Mortensen, 1903 This genus is characterized by the structure of its primary spines: a meshwork of cortical hair with a coalescent surface form a completely closed roof all over the spine including the prominent thorns, giving it the appearance of being totally smooth. Test: Low, flattened above and below, rather small form. Apical system: About half the test diameter; monocyclic, the ocular plates being insert; all genital plates of same size; gonopores in females larger than in males; periproctal plates rather few and large; all plates densely covered by small tubercles of uniform size. Ambulacra: Conjugate pore pairs, pore zones depressed, interporiferous zone wider than pore zone; regular row of marginal tubercles, inner space with smaller tubercles; median suture slightly incised. Interambulacra: 7–9 plates per column; areoles transverse oval and depressed, scrobicular circles contiguous or confluent throughout; scrobicular tubercles well differentiated, secondary tubercles filling the median zone forming horizontal rows, vertical suture incised, but usually no naked median band. Peristome: Slightly smaller than apical disc; interambulacral plates not reaching the mouth edge. Primary spines: Long, short collar and neck; shaft with strong thorns; meshwork of cortical hair covered by closed outer surface. Secondary spines: Narrow and flattened. The genus consists of three species living in the western Pacific: Schizocidaris assimilis Mortensen, 1903. Sulu Islands, ­Philippines.

Schizocidaris fasciata Mortensen, 1927. Malayan Archipelago. Schizocidaris serrata Mortensen, 1903. Philippines, deeper water. Schizocidaris assimilis Mortensen, 1903 (Fig. 4.57 A, B) Test: Diameter may reach 23 mm. Apical plates: Densely tuberculated. Primary spines: In length, 1.5 to 2 times the diameter of test; tapering gradually into a rather fine point; shaft set with numerous sharp, coarse thorns, forming two lateral series and often an additional median row on the adapical side; more rarely the thorns are arranged in more or less distinct 3–5 longitudinal rows; adoral side of the shaft nearly smooth or at most set with irregular, small thorns; surface covered with a close crust over a meshwork of cortical hair, giving it a smooth and shiny appearance; adapical spines half the length of ambital ones; oral primaries very slender and with lateral serrations. Secondary spines: Scrobiculars scarcely 2  mm long, smooth, flat, and thin with straight-cut end and nearly parallel sides; marginal spines distinctly more slender, sometimes slightly widened toward the point. Color: The primary spines are pure white; the secondaries and the test show a yellow white or faint purplish. The naked test has usually a more or less distinct green tint, which may continue toward the peristome; the genital plates and the periproct are the darkest green. The test may also be pale purple. The tube feet are white. Distribution: This species is found in the Malayan Archipelago and the Philippines at a depth of about 180 to 300 m. Schizocidaris fasciata Mortensen, 1927 The single specimen reported by Mortensen is a juvenile of 8 mm length. Apical plates: Covered with scattered tubercles of uniform size. Ambulacra: Marginal tubercles not contiguous and not much smaller than scrobicular tubercles; a single inner tubercle per plate; median area naked. Interambulacra: Only a few extrascrobicular tubercles, median zone naked and somewhat sunken; horizontal sutures depressed forming rather distinct grooves. Primary spines: Nearly cylindrical, hardly tapering to a small distal crown; at the base with a few larger thorns, shaft otherwise set with numerous smaller thorns decreasing in size distally, arranged in fairly distinct longitudinal series; oral spines slender. Scrobicular spines: Thin and flat, with straight-cut end and parallel sides, marginal spines more slender.

4.1.1 Order: Cidaroida Claus, 1880 



A

C

 113

B

D

E

Fig. 4.57: (A, B) Schizocidaris assimilis. (A) Side view of test, diameter 19 mm; Kei Islands, Indonesia. ZMUC. The small extrascrobicular tubercles are arranged in horizontal rows. (B) Aboral side with spines, diameter of test 22 mm; Kei Islands, Indonesia. ZMUC. The primary spines are set with 2 to 3 rows of large thorns decreasing in size toward the distal end. (C–E) Schizocidaris serrata. (C) Oral side of test, diameter 22 mm; Palawan, Philippines. The conspicuously dark tube feet continue over the peristome. (D) Aboral side with spines, diameter of test 21.5 mm; Philippines. ZMUC ECH 464. (E) Oral side with spines.

Color: Primary spines white with 2 to 3 fairly distinct broad bands in pink, the secondaries and the test yellow white. The denuded test is white; the genital plates are green. Distribution: The specimen reported by Mortensen was collected off Jolo, Philippines. Depth 283 m. Schizocidaris serrata Mortensen, 1903 (Fig. 4.57 C–E) Ambulacra: Marginal tubercles not contiguous, median area of plate set with a few smaller tubercles; vertical suture forming a sunken zigzag band. Interambulacra: Extrascrobicular tubercles small and numerous, arranged in horizontal series; horizontal grooves well marked on the median zone, less so at the outer edge. Primary spines: With sharp thorns, decreasing in size toward the small point; surface covered with a crust of cortical hair.

Color: Primary spines white, test and secondary spines yellowish white or purplish; genital plates green or purplish; tube feet conspicuously dark continuing onto the peristome. Remarks: This species resembles Schizocidaris assimilis and S. fasciata very much. But the thorns along the primary spines of S. serrata are smaller than in the two other species, and the tube feet are conspicuously darker, especially on the oral side, where they continue onto the peristome.

Subfamily Stereocidarinae Lambert, 1900 This subfamily is characterized by its uppermost primary tubercles being more or less rudimentary. The tubercles are perforated and usually not crenulated. Often there

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 4.1 Subclass Cidaroidea Smith, 1984

are distinct grooves in the horizontal sutures of the interambulacra. The gonopores are larger in females than in males. Two genera are included, which are very similar: Phalacrocidaris Lambert, 1902. Monospecific. Stereocidaris Pomel, 1883. 18 species. They differ by the following characteristics: Phalacrocidaris shows 2 to 3 non-functional primary tubercles per column, which means there are no primary tubercles above the ambitus. In Stereocidaris, only one or two adapical tubercles are rudimentary, not carrying primary spines. Genus Phalacrocidaris Lambert, 1902 Mortensen (1928) described this cidarid as Stereocidaris (Phalacrocidaris), Kroh & Mooi (2010) raised the subgenus to genus level. The uppermost 2 or 3 tubercles are rudimentary, not carrying a functional primary spine.

A

Phalacrocidaris japonica Döderlein, 1885 (Fig. 4.58 A, B) Test: Of medium size, solid, usually very densely tuberculated; in profile subconical. Apical system: Slightly elevated, in diameter half the width of test; ocular plates exsert, periproct relatively small; madreporite a little larger than other genital plates. Ambulacra: Sinuate, pore pairs non-conjugate, slightly depressed; interporiferous zone more than twice the width of pore zone, regular series of marginal tubercles not contiguous, up to four slightly smaller tubercles covering inner space in vertical rows. Interambulacra: 6–9 plates in a column; uppermost 2 or 3 tubercles non-functional; areoles deep, well separated even toward the oral side; the horizontal sutures are usually distinctly incised; scrobicular tubercles faintly differentiated; extrascrobicular areas densely covered with uniform secondaries; pits or incised sutures along the horizontal sutures weakly developed.

B

C

D

Fig. 4.58: (A, B) Phalacrocidaris japonica. Aboral side of test, diameter of female 33 mm, diameter of male 36 mm; Yamagato Bay, Japan. ZMUC. The female has large gonopores, the male small ones. The tubercles on the aboral side do not carry primary spines. (B) Aboral side with spines, diameter of test 27 mm; Sagami Bay, Japan. ZMUC. The primary spines are very slender. (C) Stereocidaris alcocki. Aboral side with some spines, diameter of test 32 mm; Indian Ocean. ZMUC. The primary spines are provided with lateral wings. (D) Stereocidaris capensis. Side view with some remaining spines, test diameter 28 mm; off East London, South Africa. ZMH E 282. The primary spines are set with distinct ridges.



Peristome: Smaller than apical system; interradial plates not reaching the mouth. Globiferous pedicellariae: With a small end tooth, valves very slender. Primary spines: Long, slender, and cylindrical, sometimes slightly widened at the point; collar short; shaft set with finely serrated ribs. Secondary spines: Scrobicular spines flat, rather broad and gently tapering to a rounded point, slightly appressed; marginal spines flattened and rather slender, other secondaries not very short, slightly flattened, and not appressed. Color: In general, brown yellow; primary spines of uniform red brown to gray brown, collar and neck in pink; denuded test uniformly white. Distribution: Phalacrocidaris japonica is recorded in Japanese waters from Sagami Bay, off Kyushu, and in the Japan and East China Sea. Bathymetric range 700 to 900 m. Genus Stereocidaris Pomel, 1883 This genus is characterized by the uppermost one or two primary tubercles being rudimentary and not carrying a functional spine. Test: Solid. Apical system: Ocular plates exsert or just insert; genital plates of same size, rather high, consequently periproct small; all plates densely tuberculated. Ambulacra: Sinuate; pore pairs narrow and nonconjugate; interporiferous zone with regular vertical row of marginal tubercles and smaller inner ones more or less arranged in horizontal series. Interambulacra: Deeply sunken areoles; up to 8 plates per column; well differentiated and contiguous scrobicular tubercles; extrascrobicular zone densely covered by uniform tubercles; rudimentary tubercles on uppermost fully developed plates; adapical plates taller than wide; horizontal sutures incised, small but distinct pits at the median triple suture junctions. Primary spines: More or less stout, often slightly fusiform, shaft set with serrated or granuled ridges. Remark: Eighteen Recent species of Stereocidaris are described, ten of them alone by Mortensen. Beside these species, Döderlein established some varieties for S. indica and S. alcocki; Mortensen introduced further ones for grandis, granularis, indica, sceptriferoides, and tubifera, mostly on the base of very few specimens. Rowe & Hoggett (1986) noted: “Obviously little variation within a species or variety seems to have been allowed”. They assume that a reexamination of the genus including Mortensen’s material would reveal considerably fewer

4.1.1 Order: Cidaroida Claus, 1880 

 115

species and varieties of Stereocidaris. I show here specimens from the collection in Copenhagen determined by Mortensen himself. Stereocidaris alcocki Anderson, 1894. Indian Ocean. Stereocidaris capensis Döderlein, 1901. South Africa. Stereocidaris excavata Mortensen, 1932. South Africa. Stereocidaris grandis Döderlein, 1885. Japan. Stereocidaris granularis Mortensen, 1928. Philippines. Stereocidaris hawaiiensis Mortensen, 1928. Hawaii. Stereocidaris indica Döderlein, 1901. Japan, Philippines, Indian Ocean. Stereocidaris ingolfiana Mortensen, 1903. North Atlantic. Stereocidaris leucacantha A. Agassiz & H. L. Clark, 1907. Hawaii. Stereocidaris microtuberculata Yoshiwara, 1898. West Pacific. Stereocidaris nascaensis Allison, Durham & Mintz, 1967. East Pacific. Stereocidaris purpurascens Mortensen, 1928. Philippines. Stereocidaris reducta Mortensen, 1939. Indian Ocean. Stereocidaris sceptriferoides Döderlein, 1887. West Pacific. Stereocidaris squamosa Mortensen, 1928. Indian Ocean. Stereocidaris stylifera Mortensen, 1928. Philippines. Stereocidaris sulcatispinis Mortensen, 1928. Philippines. Stereocidaris tubifera Mortensen, 1928. Philippines. Literature: Döderlein 1885, 1887; Mortensen 1903, 1928, 1932, 1939; Pawson 1965; Allison et al. 1967; Phelan 1970; A. M. Clark & Courtman-Stock 1976; Rowe & Gates 1995; Hoggett & Rowe 1986; Rowe & Hoggett 1986, Shigei 1986; McKnight 2009. Stereocidaris alcocki Anderson, 1894 (Fig. 4.58 C) Main characteristics of the genus; large form. Interambulacra: Below ambitus with vertical sutures often forming a sunken space. Peristome: About 25 % of test diameter. Primary spines: Typically with three keels, very long. Scrobicular spines: Ridged. Distribution: The species is restricted to the Indian Ocean. Döderlein (1906) recorded a bathymetric range of 371 to 750 m. Stereocidaris capensis Döderlein, 1901 (Fig. 4.58 D) Test: Moderately high, upper side elevated, may be almost spherical; diameter up to about 36 mm. Apical system: Nearly half the test diameter, peristome distinctly smaller. Interambulacra: Upper horizontal sutures rather broad and sunken; ambital sutures with fairly distinct grooves at the median line.

116 

 4.1 Subclass Cidaroidea Smith, 1984

Primary spines: Stout, with about 20 longitudinal ridges. Secondary spines: Scrobicular ones slightly keeled; marginal spines broad and flat. Color: Light brown, scrobicular spines often with darker tip. Distribution: The species is restricted to the waters around South Africa. Depth about 500 m. Stereocidaris excavata Mortensen, 1932 (Fig. 4.59 A, B) Mortensen recorded a test diameter of 69 mm. Test: Almost globular with abruptly flattened upper side. Apical system: Flat or even sunken; genital plates more or less distinctly depressed around the elevated, centrally positioned gonopore, periproct may be slightly raised.

A

C

Ambulacra: Interporiferous zone twice the width of pore zones; marginal tubercles contiguous, inner tubercles densely and more or less serially distributed. Interambulacra: Deeply sunken areoles, scrobicular tubercles positioned at the slope; extrascrobicular space densely tuberculated with radiating lines across the midline; pits carrying pedicellariae along upper horizontal and vertical sutures. Primary spines: Slender, cylindrical, about 12 finely serrated low ridges, tips fluted. Secondary spines: Scrobiculars strongly appressed, rather thick and chisel-shaped; marginal spines similar but shorter.

B

D

Fig. 4.59: (A, B) Stereocidaris excavata. (A) Aboral side of test, diameter 55 mm; East London, South Africa. ZMUC ECH 155. The genital plates are sunken around the raised, centrally positioned pores. (B) Aboral side with spines, diameter of test 58 mm; off East London, South Africa. ZMUC. The secondary spines are strongly appressed. (C, D) Stereocidaris grandis. (C) Aboral side with spines. Diameter of test 43 mm; mouth of Tokyo Bay, Japan. The primary spines are covered by regular granules. (D) Side view of test, diameter 50 mm; Bonomisaki, Japan. ZMUC ECH 570. The areoles are deeply depressed.



Color: Light brown to creamy white with green olive secondary spines. Distribution: Restricted to South African waters at a depth of 120 to 177 m. Differentiation: There are two species of Stereocidaris in South Africa. They differ clearly in the shape of the primary spines and the apical region: S. capense has stout primaries and an elevated apical disc; in S. excavate, the spines are more slender and the apical disc is sunken or at least flattened. Stereocidaris grandis Döderlein, 1885 (Fig. 4.59 C, D) Test: Very massive, upper and lower side more or less convex or subconical; sometimes forming almost a globe; diameter may reach 67 mm. Apical disc: Half the diameter of test, periproct pentagonal with more or less pointed plates toward the insert oculars. Ambulacra: Sunken pore zones, broad interporiferous zone; aborally regular row of marginal tubercles, inner tubercles smaller and forming up to 6 vertical series; orally very irregular. Interambulacra: Areoles deep; one or two uppermost tubercles rudimentary; scrobicular tubercles differentiated, extrascrobiculars densely distributed, decreasing in size toward the midline; arranged in series separated by radiating lines crossing the midline; all plates arched. Peristome: More than one third of test diameter. Primary spines: Slightly longer than test diameter; cylindrical, at the base with longitudinal series of granules, distally with ridges, sometimes flaring; oral primaries flattened. Secondary spines: Scrobiculars broad, marginal spines more slender; other secondaries rather short, on upper side scale-like, strongly appressed, on oral side thickened, more or less club- shaped and crowded. (Mortensen 1928 established a var. hyatorina, which has slender and regularly arranged secondary spines on the oral side.) Color: In general, yellow brown; scrobicular spines often with brown midline; secondary spines red brown, sometimes with lighter tips; primary spines gray brown, collar red; denuded test white, upper side with yellow gray tint. Distribution: The species is restricted to Japanese waters, from Sagami Bay to south of Kyushu. Bathymetric range 70 to 700 m. Remark: M. Shigei (1986) stated this species and Stereocidaris microtuberculata being synonymous.

4.1.1 Order: Cidaroida Claus, 1880 

 117

Stereocidaris granularis Mortensen, 1928 (Fig. 4.60 A–C) Test: Rather low, flattened above and below; maximum diameter may reach 60 mm. Apical system: Flat or only slightly raised; plates mostly broader than high; densely tuberculated. Ambulacra: Interporiferous zone twice the width of pore zone; marginal tubercles more or less irregular in shape, contiguous; inner space densely filled with smaller tubercles. Interambulacra: Areoles moderately large, only adorally confluent, edges not raised; scrobicular tubercles low and rather inconspicuous; extrascrobiculars in rows, separated by lines; uppermost plates with sunken bands along the horizontal sutures, ambitally small pits at the ends of the horizontal sutures; plates on the whole almost flat. Primary spines: Slender, cylindrical; point simple or with a small terminal widening, obliquely directed downward; shaft set with about 14 longitudinal series of fairly sharp spinules, distally becoming ridges; collar short, thickening toward the milled ring, neck shining; oral primaries with ridges. Secondary spines: Scrobiculars about 4 mm long, flat or convex, slightly narrowing toward the straight-cut end; marginal spines 2  mm long and more slender; smaller spines scale-like and appressed. Color: In general, light brown to yellow; primary spines cream, sometimes with faint ring between collar and neck; secondary spines with olive green tint, red or green midline; adapical secondary spines more red brown, rarely white. Denuded test white with a rosy tint at the apical plates continuing down the upper interambulacra. Distribution: This species is found in the Philippines and the Malayan Archipelago. Recorded depth about 250 to 510 m. Remark: Mortensen (1927) established a variety Stereocidaris granularis var. rubra (Fig. 4.60 D): the test is almost entirely bright red except for the white pore zones and the inner parts of the areoles. The secondary spines are also reddish, especially the scrobicular ones, the primary spines are light rosy. Superficially this species resembles Compsocidaris pyrsacantha (see below). It differs in having granuled primary spines, whereas C. pyrsacantha has totally smooth spines. Stereocidaris hawaiiensis Mortensen, 1928 (Fig. 4.60 E) Test: More or less high with flattened oral side. Apical system: High and arched, plates themselves thick and also raised, sutures sunken forming conspicuously naked bands along inner edge of genital plates; female pores not much larger than male pores.

118 

 4.1 Subclass Cidaroidea Smith, 1984

A

C

B

D

E

Fig. 4.60: (A–C) Stereocidaris granularis. (A) Aboral side with spines, test diameter 53 mm; Bohol, Philippines. The primary spines are very slender. (B) Close-up of apical disc: the secondary spines are strongly appressed. (C) Aboral side of test, diameter 45 mm; Balicasag, Philippines. The rosy tint of the apical plates continue onto the interambulacral plates. (D) Stereocidaris granularis var. rubra. Side view of test, diameter 54 mm; Balicasag, Philippines. The test is almost entirely red. (E) Stereocidaris hawaiiensis. Aboral side with some remaining spines, test diameter 32 mm; off Hawaiian Islands. ZMUC ECH 157. The primary spines are rather stout and slightly thickened above the neck.

Interambulacra: Upper horizontal sutures with rather conspicuous pits; ambital sutures sunken at the depressed median line. Primary spines: Distinctly fusiform and tapering distally; shaft set with 16–18 series of low spinules; oral primaries simple, slightly fusiform. Marginal spines: Rather broad. Color: In general, pale olive gray; apical disc with pale green tint; scrobicular spines with green median stripe.

Distribution: Known only from around the Hawaiian Islands. Bathymetric range 285 to 455 m. Stereocidaris indica Döderlein, 1901 (Fig. 4.61 A, B) Test: Upper side subconical; diameter may reach more than 44 mm. Ambulacra: Marginal tubercles small, not contiguous. Interambulacra: Subambital median suture may be sunken, at least showing distinct pits.

4.1.1 Order: Cidaroida Claus, 1880 



A

 119

B

C

D

Fig. 4.61: (A, B) Stereocidaris indica. (A) Aboral side with spines, test diameter 39 mm; off Somalia, East Africa. ZMUC. The two uppermost primary tubercles per column are non-functional. (B) Side view: the test is in profile subconical. (C, D) Stereocidaris ingolfiana. Side view of test, diameter 35 mm; off southwest Iceland. ZMUC ECH 368. The test is typically flattened aborally with steep sides. (D) Aboral side with spines, test diameter 22 mm; west of Ireland. Only the uppermost tubercles are rudimentary, the spines are set with wings.

Peristome: Small, in width about 25 % of horizontal diameter; only 6–7 peristomial ambulacral plates and 1–2 interradial plates. Primary spines: Very variable from tapering to a small point to distally flaring forming a crown; up to 30 longitudinal ridges or rows of more or less prominent granules; oral primaries smooth and curved. Secondary spines: Scrobiculars not much appressed; marginal spines very slender. Color: In general, brownish; the primary spines with rosy neck. Distribution: This species is known throughout the IndoWest Pacific from East Africa to the Philippines and Japan.

Mortensen (1928) stated a bathymetric range from 400 to 1,289 m. Stereocidaris ingolfiana Mortensen, 1903 (Fig. 4.61 C, D) Test: In specimens from the West Indies usually low, flattened above and below, specimens from more northern localities often being higher, aborally flat with steep sides; diameter may reach 38 mm. Ambulacra: Marginal tubercles in a regular row, not continuous; inner tubercles smaller and irregularly arranged, often obscuring the midline. Interambulacra: Small pits in the vertical suture.

120 

 4.1 Subclass Cidaroidea Smith, 1984

Primary spines: Strongly developed rows of spinules, often fused into wings with more or less serrated edges (Mortensen 1928 emphasized that there occur also specimens without any wings); oral primaries short with small serrations; scrobicular spines simply flattened. Color: In general, uniformly beige brown with rosy collars at the primary spines. Distribution: This species is recorded in the Northern Atlantic from the Denmark Strait to Cape Verde and along the east coast of America to the Caribbean. Bathymetric range 300 to 1,745 m. Stereocidaris leucacantha A. Agassiz & H. L. Clark, 1907 (Fig. 4.62 A, B) Test: May be flattened above and below or regularly arched aborally; diameter may reach 55 mm. Apical plates: Usually flat, often surrounded by rather bare edges. Ambulacra: Contiguous marginal tubercles; inner tubercles smaller and irregular. Primary spines: Slender; in length, 1.5 to 2 times the test diameter; about 12 longitudinal ridges with distinct granules; oral primaries fluted toward the end. Secondary spines: Scrobiculars about 4 mm with almost parallel sides; marginal spines more slender than in S. hawaiiensis. Color: Collar of primary spines light purple with a narrow, dark ring at the limit to the neck; sometimes the secondary spines show a more or less distinct median stripe. Distribution: Endemic to the Hawaiian Islands. Depths recorded by Mortensen about 300 to 950 m. Remark: There are two endemic species occurring around the Hawaiian islands that differ considerably: S. hawaiiensis has fusiform primary spines of uniform color and usually arched apical plates, while S. leucacantha possesses slender, cylindrical primary spines with a dark band between collar and neck and flat apical plates. However, hybrids between these two species have been found. Stereocidaris microtuberculata Yoshiwara, 1898 (Fig. 4.62 C) Test: Large form; diameter of test may reach 79 mm; upper side slightly arched. Apical system: Genital plates broader than high, pores rather small. Ambulacra: Marginal tubercles contiguous, not always regular; inner zone completely filled with smaller tubercles, separated by fine transverse lines only partly corresponding with sutures; no naked or sunken median line. Interambulacra: Areoles small, but deep, well separated also adorally; ring of scrobicular tubercles not prominent,

extrascrobicular space densely covered by small tubercles arranged in fairly regular horizontal series, separated by fine lines; sutures slightly depressed, no naked midline or depressions. Primary spines: Vary in length from as long as diameter of test to twice the diameter; shaft cylindrical, rather smooth with 12–14 series of low granules distally becoming rather sharp, low ridges; tip sometimes flaring, edge obliquely downward cut; densely covered by cortical hair. Secondary spines: Scrobiculars 5–6  mm long, slightly tapering; marginal spines 2–3 mm long. Color: In general, creamy white with a faint tint of reddish brown or green; scrobicular spines with darker stripe; denuded test with slightly red brown apical disc continuing over the upper interambulacra. Distribution: Mortensen (1928) reported this species only from Japan, but McKnight (2009) lists it also from New Zealand waters. Rowe & Hoggett (1986) recorded this species from New South Wales, eastern Australia. So it is very likely that this species also occurs in the Malayan Archipelago and the Philippines. Remark: Shigei (1986) regarded Stereocidaris microtuberculata as synonymous to S. grandis. Stereocidaris nascaensis Allison, Durham & Mintz, 1967 (Fig. 4.62 D, E) Test: Low with slightly arched upper side and flattened oral side. Apical system: Half the diameter of test in width; inner edges of genital plates with broad naked bands. Ambulacra: Marginal tubercles small, not at all continuous, pore pairs oblique. Interambulacra: 4–5 plates per column; areoles small, well separated aborally and adorally; scrobicular tubercles only slightly larger than other secondaries, naked space along the plate sutures at the aboral side. Peristome: Relatively large, about 35–40 % of test diameter. Primary spines: In length, probably 2 times the diameter of test, cylindrical, slightly tapering distally; shaft set with 10–11 rows of closely spaced low granules; oral primaries slender with fluted ends. Secondary spines: Scrobiculars flattened and spatulate, appressed around the base of the primaries; marginal spines slender, half to a third of length of scrobiculars; short spinelets on apical plates. Color: In general, a bright brick red; secondary spines yellow with red bases; primary spines with dark purple bases. In specimens preserved in alcohol, the color fades out, and only the purple on the spines remains.

4.1.1 Order: Cidaroida Claus, 1880 



A

 121

B

C

D

E

Fig. 4.62: (A, B) Stereocidaris leucacantha. (A) Aboral side of test with a few remaining spines, diameter of test 33 mm; Hawaii. ZMUC. (B) Side view of test. The apical plates are flat, not arched as in Stereocidaris hawaiiensis. (C) Stereocidaris microtuberculata. Aboral side with some spines, test diameter 67 mm; Sagami Bay, Japan. ZMUC. (D, E) Stereocidaris nascaensis. Side view with some remaining primary spines, diameter of test 50 mm. Seamount at the southwest end of the Nasca Ridge, Southeast Pacific. ZMUC. (E) Aboral side.

122 

 4.1 Subclass Cidaroidea Smith, 1984

Distribution: This species was found only on seamounts in the Southeast Pacific. Bathymetric range about 200– 240 m (according to A. Mironov, who gave the specimen to the ZMUC collection). It seems to be the only species of Stereocidaris living in the East Pacific. Stereocidaris purpurascens Mortensen, 1928 (Fig. 4.63 A, B) Test: Rather low with slightly arched upper side; diameter may reach at least 43 mm.

A

Apical system: Plates flat, separated by more or less distinct naked sunken lines. Ambulacra: Regular marginal tubercles, contiguous, inner space with a fairly regular row of secondaries on each side, at the ambitus additional small tubercles; no naked or sunken midline. Interambulacra: Areoles rather large; scrobicular tubercles moderately differentiated; median space scarcely more than one third of width of an areole; midline slightly

B

C

D

Fig. 4.63: (A, B) Stereocidaris purpurascens. (A) Aboral side of test, Diameter 35 mm; Kei Island, Indonesia. ZMUC ECH 270. The apical plates are separated by distinctly sunken naked bands, which sometimes seem to form widened pits (arrow). The apical system is developed anomalously, genital 3 consisting of 2 plates. (B) Side view: the test is rather flat. (C, D) Stereocidaris reducta. (C) Side view of test with some remaining spines, diameter 61 mm; Maldives. ZMUC ECH 285. (D) Aboral side of test. The small spines covering the entire surface are tightly appressed.



sunken, upper horizontal sutures usually showing a series of 3–5 small but distinct grooves; vertical suture with small pits at the ambital triple junctions. Peristome: In width, about 35–44 % of test diameter. Primary spines: In length, usually twice the diameter of test; cylindrical and slender; shaft rather smooth with about 14 faintly granuled ridges, becoming more distinct toward the slightly tapering distal end; collar 2 mm long, conspicuously thickened toward the milled ring; oral primaries slightly widened, not serrated, but fluted. Secondary spines: Scrobicular ones about 5  mm in length, somewhat tapering toward the rounded end, rather thick and appressed; marginal spines about 3 mm long, flattened, appressed. Color: In general, whitish with the uppermost part of the test yellow brown; primary spines white, sometimes with darker end, not fully developed spines of conspicuous dark purple; scrobicular spines with median stripe; denuded test white, genital plates yellow brown, other apical plates lighter. Distribution: The species is recorded from the Malayan Archipelago and the Philippines. Bathymetric range about 200 to 450 m. Stereocidaris reducta Mortensen, 1939 (Fig. 4.63 C, D) Test: Almost spherical, upper side arched, recorded diameter of test up to 64 mm. Apical system: Ocular plates insert; all plates densely covered by a fine and uniform tuberculation partly arranged in radiating rows separated by fine, sharply incised lines. Ambulacra: In width about one third of interambulacra; interporiferous zone broad, twice the width of pore zone; marginal tubercles very regular, small but continuous; inner space closely set by not much smaller tubercles, up to six per plate forming more or less irregular horizontal series; no naked median line, horizontal sutures distinct. Interambulacra: Small, deep areoles, well separated even to the peristome; up to two adapical plates with rudimentary tubercles: as these plates are rather high, most of the aboral side is devoid of primary spines; scrobicular ring rather distinct, extrascrobicular space broad, well developed also at the outer side of the plates; closely set with small tubercles usually arranged in radiating rows separated by fine, sharply incised lines; midline at ambitus with small pits carrying large globiferous pedicellariae often present also on an interambulacral plate itself. Peristome: Of about same size as apical system. Primary spines: Slender, cylindrical, or tapering into a point, sometimes with terminal crown; shaft set with about 15 smooth or very finely serrated ridges; oral primaries distally widened and fluted.

4.1.1 Order: Cidaroida Claus, 1880 

 123

Secondary spines: Scrobiculars 4 mm long, almost rectangular, closely appressed; marginal spines 3 mm long, also well appressed; other secondaries very small. Color: In general, light brown; primary spines light pink; scrobicular spines with dark olive stripe; denuded test aborally conspicuously green, becoming reddish below the ambitus. Distribution: Mortensen (1939) recorded this species only from off the Maldives at a depth of 229 m. Stereocidaris sceptriferoides Döderlein, 1887 (Fig. 4.64) Test: Rather low, flattened above and below; max diameter of test about 40 mm. Apical system: All plates covered by moderately dense tubercles leaving distinctly sunken, rather broad naked spaces along the inner and lateral edges of the genital plates. Ambulacra: Regular rows of small marginal tubercles being not contiguous; inner space with irregularly arranged smaller tubercles, midline more or less sunken. Interambulacra: Areoles well separated, adapically only a single rudimentary tubercle; edge of areoles raised; scrobicular tubercles rather distinct; extrascrobicular tubercles decreasing in size toward the sunken midline, median space about half the width of an areole; horizontal sutures more or less sunken, often with a groove at the median end; upper horizontal sutures with a single, rather broad, but not well-defined depression. Peristome: Nearly as large as apical disc. Primary spines: In length, up to twice the diameter of test; rather thick, often slightly fusiform, gently tapering toward the tip, sometimes with a flaring crown; 12–15 longitudinal series of rounded granules; collar 1  mm long, smooth neck double the length; oral primaries slightly widened, with faintly serrated edges, surface smooth. Secondary spines: Scrobicular ones often unusually broad, in other specimens being much narrower and almost pointed; in length, 3–4 mm; marginal spines more or less slender. Color: Test in general light brown, primary spines with brown pink tint distally fading out; secondaries sometimes with a faint tinge of green olive; denuded test white. Distribution: West Pacific from Japan to New Zealand. Bathymetric range about 360 to 1,040 m. Stereocidaris squamosa Mortensen, 1928 (Fig. 4.65 A, B) Test: Diameter may reach 47 mm. Apical system: At least narrow naked bands along the plate edges. Ambulacra: Marginal and inner tubercles in regular vertical series; horizontal sutures below pore pairs depressed. Interambulacra: Distinct pits along horizontal sutures.

124 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

Fig. 4.64: Stereocidaris sceptriferoides. (A) Side view with spines, diameter of test 28 mm; Sagami Bay, Japan. ZMUC. The primary spines are set with prominent rows of rounded granules. (B) Aboral side of test with a few remaining spines, diameter 33 mm; Bonomisaki, Kyushu, Japan. ZMUC. The genital plates are more or less pointed distally. (C) Side view. The test is relatively low with strongly incised areoles.

Peristome: About one third of test diameter. Primary spines: Cylindrical, oral primaries coarse, longitudinally fluted. Color: Yellow green; scrobicular spines faint green or purple; collar dark purple or at least with dark line toward the neck. Distribution: Mortensen (1928) recorded this species only from the Saya de Malha Bank, Indian Ocean at a depth of 270 m.

Stereocidaris stylifera Mortensen, 1928 Test: Gently arched above, flattened below; recorded specimen measures 55 mm in diameter. Apical system: Usually well insert, genital plates higher than broad; all plates densely covered by small tubercles of uniform size, fine radiating incised lines. Ambulacra: Broad, about 30 % of horizontal diameter; small marginal tubercles contiguous and regular; inner

4.1.1 Order: Cidaroida Claus, 1880 



 125

A B

C

D

Fig. 4.65: (A, B) Stereocidaris squamosa. (A) Side view of test, diameter 30 mm; Saya de Malha Bank, Indian Ocean. ZMUC ECH 419. (B) Aboral side of test with a single spine. (C, D) Stereocidaris tubifera. Side view of test, partly with spines, diameter 71 mm; Kei Islands, Indonesia. ZMUC ECH 316. The small secondary spines are very short, only 1 mm long. (D) Close-up of aboral side.

tubercles still smaller and irregular, tending to form transverse rows; in the midline occurs a rather conspicuous series of small grooves (in which large globiferous pedicellariae are located). Interambulacra: Areoles well separated; ring of scrobicular tubercles fairly distinct; extrascrobicular space densely covered by small tubercles of uniform size; fine but distinctly incised lines cross the slightly sunken median suture; sometimes small grooves occur in the upper and ambital horizontal sutures and also here and there on the plates themselves. Primary spines: Slender, cylindrical, probably not very long, may end in a crown; about 14 regular rows of low spinules; oral primaries slender, not widened and more or less fluted distally. Secondary spines: Scrobicular ones 6–7 mm long, tapering to a narrow, rounded point; marginal spines about 4  mm long, not flattened, but round, tapering to a fine point; other small secondaries rather broad, scale-like, appressed.

Color: The test is in general red brown to pink, darkest on the apical system. The scrobicular spines are dull gray olive with indistinct brown median stripe. The primary spines appear to be dull gray, with white neck and gray olive collar. The denuded test is whitish with the apical system being red pink. Occurrence: The specimen was dredged in the Samar Sea, Philippines. Depth 247 m. Stereocidaris sulcatispinis Mortensen, 1928 Test: Slightly arched aborally; recorded test diameter 48 mm. Apical system: Densely covered by small uniform tubercles, ocular plates narrowly insert or exsert. Ambulacra: Interporiferous zone scarcely twice the width of pore zone; marginal tubercles regular and contiguous, median space filled by a fairly regular row of slightly smaller tubercles to each side plus very small ones along the median suture.

126 

 4.1 Subclass Cidaroidea Smith, 1984

Interambulacra: Areoles large, subambitally transverse oval; scrobicular tubercles distinct; extrascrobicular ones dense and uniform; grooves in aboral horizontal sutures inconspicuous, small pits at the median end; incised lines present. Primary spines: In length, 1.5–2 times the diameter of test, cylindrical, slightly tapering; shaft set with about 12 low ridges, smooth or at most faintly granuled toward the distal end. Secondary spines: Scrobicular ones about 5  mm long, flat, tapering to a rounded end; marginal spines 2  mm long, flat, rather broad; small spines scale-like, appressed. Color: Secondary spines white with faint olive green or red brown stripe; primary spines white with pink tint at the base; naked test white with red tint on the apical plates continuing onto the upper interambulacral plates. Distribution: Probably widespread in the Malayan Archipelago and the Philippines, 200 to 400 m. Stereocidaris tubifera Mortensen, 1928 (Fig. 4.65 C, D) Test: Flattened above, less so below; diameter of test may reach 71 mm. Apical system: Quite flat, genital plates higher than wide, almost rectangular; all ocular plates insert with a rather deep notch in the outer edge; all plates densely covered by small, uniform tubercles, fine incised lines present. Ambulacra: Marginal tubercles in a regular series, contiguous, but not prominent; inner space irregularly filled with smaller tubercles, fine incised lines crossing the midlines, sutures themselves indistinct. Stereocidaris granularis Stereocidaris indica Stereocidaris microtuberculata Stereocidaris purpurascens Stereocidaris sceptriferoides Stereocidraris stylifera Stereocidaris sulcatispinis Stereocidaris tubifera

Interambulacra: Areoles fairly large and deep, wellseparated; scrobicular edge not raised, scrobicular tubercles oval, not very large, but conspicuous in contrast to the much smaller extrascrobicular tubercles filling closely and uniformly the median space; midline hardly sunken; fine incised lines present; as also depressions in the upper horizontal sutures. Peristome: Up to 16 ambulacral plates in a column. Primary spines: About 1.5 times the horizontal diameter; cylindrical, only slightly tapering; subambital ones with distinct terminal widening; shaft set with 18–20 rows of low spinules; lowermost oral primaries flattened, but the second one starts flaring conspicuously. Secondary spines: Scrobiculars about 6  mm long, flattened, slightly tapering to the straight-cut end, marginal spines about 3 mm long, flattened; small spines only 1 mm long. Color: Test in general light brown to creamy white; primary spines with pinkish tint; scrobicular spines of a faint olive green. Denuded test white, sometimes with an olive green tinge. Distribution: Mortensen (1928) reported this species from the Malayan Archipelago and the Philippines. Bathymetric range about 300 to 400 m. Supports for identification Most of the species of Stereocidaris live in the western Pacific, mainly around the Philippines. Here I list a few coarse characteristics for supporting the differentiation of these species.

Denuded test aborally red, var. rufa totally red. Peristome very small, in width about 25 % of test diameter. Large form, primary spines with trumpet-shaped end. Young primary spines purple, pits in upper horizontal grooves and on apical plates. Upper horizontal sutures in interambulacra with single, not well limited depression; globiferous pedicellariae with very narrow valves. Grooves in interporiferous zone, in interambulacral sutures and plates; marginal spines sharply pointed and round, not flattened. Marginal spines broad and flat. Extrascrobicular spines uniform, very small, and very numerous, strongly contrasting to the much larger scrobicular spines.

4.1.1.2 Family Histocidaridae Lambert, 1900 Primary tubercles perforated and strongly crenulated; scrobicular ring not complete, no cortical hair on primary spines; globiferous pedicellariae absent. The members of the family, one genus which lack globiferous pedicellariae, only tridentate pedicellariae are develo-

ped, mostly with 3 valves, but with only 2 valves in Histocidaris purpurata. The primary tubercles are strongly crenulated. The family consists of the single genus: Histocidaris Mortensen, 1903 Mortensen (1909) described a second genus from the northern Atlantic, Poriocidaris purpurata. Kroh & Mooi (2010) made it synonymous to Histocidaris.



Fig. 4.66: Histocidaris variabilis. Close-up of interambulacrum, diameter of test 60 mm; Hawaii. ZMUC. The tubercles are strongly crenulated from the apical disc down to the peristome.

Genus Histocidaris Mortensen, 1903 Test: High, almost globular with at least six interambulacral plates in a column. Apical system: Usually with some scattered tubercles around the pores in genital and ocular plates, most of genital plates naked; a few tubercles on periproctal plates; ocular plates usually exsert; gonopores in females larger than in males, distant from the outer edge. Ambulacra: Sinuous; pore pairs non-conjugate. Interambulacra: Primary tubercles strongly crenulated, crenulation mostly distinct also on tubercles below the ambitus; areoles not deep, confluent on ambital and oral surface; scrobicular tubercles clearly differentiated; plate sutures recognizable. Peristome: More or less pentagonal; ambulacral plates internally prolongated. Primary spines: Very slender, long, and cylindrical, smooth to thorny; oral primaries short, curved, and strongly serrated. Secondary spines: Scrobicular ones slender, long, and flattened, not appressed but rather erect around the base of the primaries, broader than other secondaries. Two forms of tridentate pedicellariae, the large one may reach a size of 5 mm, globiferous pedicellariae lacking.

4.1.1 Order: Cidaroida Claus, 1880 

 127

Biology: The female releases large yolk-rich eggs into the water column. After fecundation, the egg develops directly to a small juvenile without a pelagic larval stage or metamorphosis. The development is lecithotrophic, which means the young do not need to feed; they are nourished by the initial yolk in the egg until the mouth and the anus do function. The genus includes numerous species that are difficult to distinguish especially the naked tests. The differences worked out by Mortensen (1928) in his key (pp.  71–72) rely predominantly on the shape of the primary spines: Histocidaris acutispina Mortensen, 1927. Indian Ocean and Philippines. Histocidaris australiae Mortensen, 1928. Southeast Australia. Histocidaris carinata Mortensen, 1928. Southern Japan. Histocidaris cobosi A. Agassiz, 1898. Galapagos Islands. Histocidaris crassispina Mortensen, 1928. East Australia. Histocidaris denticulate Koehler, 1927. Indian Ocean. Histocidaris elegans A. Agassiz, 1879. Indo-West Pacific. Histocidaris formosa Mortensen, 1928. Indonesia and Philippines. Histocidaris longicollis Hoggett & Rowe, 1986. New Caledonia. Histocidaris magnifica Mortensen, 1928. Philippines. Histocidaris misakiensis Yoshiwara, 1898. Japan. Synonymous to H. elegans. Histocidaris nuttingi Mortensen, 1926. Cuba to Antigua, Antilles. Histocidaris purpurata Thomson, 1872. Northern Atlantic and Caribbean. Histocidaris recurvata Mortensen, 1928. Kei Islands, Indonesia. Histocidaris sharreri A. Agassiz, 1880. Off Nevis and Antigua, Lesser Antilles. Histocidaris variabilis A. Agassiz & H. L. Clark, 1907. Hawaii. Literature: Mortensen 1903, 1928; H. L. Clark 1907, 1946; Phelan 1970; Hoggett & Rowe 1986; Rowe & Hoggett 1986; Shigei 1986; Rowe & Gates 1995; Tracey et al. 2011. Histocidaris acutispina Mortensen, 1927 (Fig. 4.67 A–C) This species is characterized by its very long and slender primary spines. They may reach up to 4 times the test diameter and are set with irregularly arranged coarse thorns. Mortensen (1927) suggested that it may be conspecific with Histocidaris denticulata from which Koehler (1927) reported only large specimens collected in the Indian Ocean.

128 

 4.1 Subclass Cidaroidea Smith, 1984

Histocidaris australiae Mortensen, 1928 (Fig. 4.67 A–C) Test: Almost globular or slightly flattened aborally; test diameter may reach 94 mm, height 85 mm. Primary spines: More or less distinct thorns or bumps, especially in smaller specimens becoming serrated ridges toward the distal end; in larger specimens, the thorns disappear, leaving only very slight longitudinal ridges; adapical spines may be slightly trumpet-shaped; length of primary spines hardly exceeding diameter of test; oral primaries flattened and widened, coarsely indented. Scrobicular spines: Long and distinctly broader than marginal spines.

A

Color: Test dark brown, primary spines white with brown collar, secondaries brown. Distribution: Southeast coast of Australia, from Crowdy Head, New South Wales, to off Flinders Island, Bass Strait. Bathymetric range 145 to 550 m. Histocidaris carinata Mortensen, 1928 Apical system: With all oculars exsert. Peristome: remarkably small. Primary spines: About 2 times the diameter of test; may be slightly swollen above the collar. Secondary spines: With median keel; scrobicular ones twice the size of marginal ones, only a few of them outside

B

D

E

C

Fig. 4.67: (A–C) Histocidaris australiae. (A) Aboral side of female, partly with spines, diameter 62 mm; New South Wales, Australia. ZMUC ECH 87. (B) Oral side. (C) Side view of test, female, diameter 72 mm; South Australia. ZMUC. The test is almost spherical. (D, E) Histocidaris denticulata. (D) Aboral side with spines, diameter 60 mm; south of Maldives. ZMUC. The primary spines are strongly serrated. (E) Oral side: the slender oral primary spines are not curved.



of scrobicular ring, leaving a conspicuous, bare, sunken area along the midline. Color: Test brown, primary spines white, collar brown like secondary spines. Distribution: Southern Japan. Remarks: Shigei (1986) synonymized this species with H. elegans and H. misakiensis. Histocidaris cobosi A. Agassiz, 1898 Test: Maximum recorded diameter 34  mm. Flattened above and below, younger specimens relatively higher than larger ones. Ambulacra: Nearly straight, 25–30 % of width of interambulacra; series of marginal tubercles irregular. Interambulacra: Scrobicular tubercles hardly larger than marginal tubercles. Primary spines: Very long, up to 3 times the diameter; serrations very fine, minute, oral primaries only slightly serrated. Color: Test pale pinkish, cleaned test white; primary spines white and shining with brown collar; secondary spines creamy. Occurrence: Recorded from the Galapagos Island at a depth of 615 m. Histocidaris crassispina Mortensen, 1928 Only one specimen is recorded by Mortensen. Test: Rather low, flattened above; the holotype in Copenhagen measures 32 mm. Ambulacra: Marginal tubercles in regular series, not much smaller than scrobiculars, no secondary tubercles above the ambitus, only a single median series of secondaries continuing to the peristome. Interambulacra: Crenulation of tubercles distinct, scrobicular tubercles surrounded by a circle of much smaller, alternating secondary tubercles, rest of the plates rather bare, but below the ambitus, the median area is densely covered by secondary tubercles about as large as the scrobicular ones. Primary spines: Somewhat thickened in the basal part; shaft appears smooth, but is covered with faint, very finely serrated ridges. Color: Test with brownish tint; primary spines white, rather shining, collar chocolate brown. Occurrence: Off Sydney, eastern Australia, collected at 720 m. Remark: This species has only be found once. Rowe & Gates (1986) suggest that the specimen of H. crassispina might be an aberrant H. elegans because it was taken by the “Challenger” at the type locality of H. elegans (A. Agassiz) and was initially designated as a co-type of that species. Or H. crassispina might be extremely rare.

4.1.1 Order: Cidaroida Claus, 1880 

 129

Histocidaris denticulata Koehler, 1927 (Fig. 4.67 D, E) Test: Nearly spherical or flattened above and below, outline round or pentagonal. Apical system: Relatively small (36 % of diameter), ocular plates insert. Primary spines: Aborally set with thorns over the whole length of the shaft; oral primaries with coarse thorns laterally, not widened and not curved. Color: In life, the specimens may be of a more or less intensive red, the primary spines are white. Distribution: Indian Ocean from East Africa to Sumatra. Recorded bathymetric range about 400 to 741 m. Histocidaris elegans A. Agassiz, 1879 (Fig. 4.68 A–C) Test: Maximum recorded diameter 67  mm. Globular, outline round or pentagonal. Ambulacra: Marginal tubercles small, series fairly regular, inner tubercles irregular. Interambulacra: Both sides of the plates are rather bare, forming naked, more or less sunken bands along the vertical sutures. Primary spines: Very long, up to 2.5–3 times the test diameter, slender, cylindrical, with fine serrations arranged in longitudinal rows, shaft may taper and tip may be flattened; oral primaries flattened, hardly widened, strongly serrated laterally. Secondary spines: Very long and slender, scrobiculars slightly broader than other secondaries and flattened. Color: Test and spines yellow, secondary spines more chrome yellow; preserved specimens are rather brown yellow with white primary spines. Distribution: Recorded from East Australia (including the Bass Strait), northwestern Australia, and New Zealand through the whole Malayan Archipelago, off Sumatra, and the Philippines to Japan. Bathymetric range ~150 to 1,980 m. Histocidaris formosa Mortensen, 1928 (Fig. 4.68 D) Test: Large form, diameter of test may reach 83  mm. In large specimens, almost spherical. Ambulacra: Series of marginal tubercles rather irregular, median space more or less filled up with small tubercles, midline not sunken. Interambulacra: Scrobicular circle of tubercles inconspicuous, extrascrobicular tubercles hardly smaller; naked midline indistinctly sunken. Primary spines: 2–3 times the diameter of test, in large specimens less; usually a few longitudinal series of small but visible, rather sharp serrations, the two lateral ones appear to be keels, the spines thereby being more or less flattened; in larger specimens, the shaft may also be smooth and shiny with only two lateral series of small serrations; shaft

130 

 4.1 Subclass Cidaroidea Smith, 1984

A

B

C

D

E

Fig. 4.68: (A–C) Histocidaris elegans. (A) Aboral side with spines, diameter 45 mm; Port Jackson, New South Wales. ZMUC. (B) Aboral side of female, partly with spines, diameter of test 67 mm; Southeast of Australia. (C) Side view of female. (D) Histocidaris formosa. Side view with spines, diameter 71 mm; Siquijor, Philippines. The primary spines are long and slender being more or less widened distally. (E) Histocidaris magnifica. Aboral side with spines, diameter of test 64 mm; Philippines. The primary spines are long and very slender (photo by W. Clarenbach).

tapering distally, at the point often widened and trumpetshaped; oral primaries coarsely serrated and curved. Secondary spines: Scrobicular ones long and flat, basally broad, tapering toward the rounded tip; marginal spines erect. Color: Test with skin brown, denuded test white, primary and secondary spines white. Distribution: Indonesia and Philippines, 250 to 300 m. Histocidaris longicollis Hoggett & Rowe, 1986 Test: Slightly flattened; diameter of the holotype, a juvenile specimen, 19 mm.

Apical system: All oculars exsert; plates rather naked except around the anus, where the tubercles are crowded; genital pores not yet developed in holotype. Ambulacra: Only very slightly sinuous, interporiferous zone twice the width of the slightly depressed pore zone; marginal tubercles in a regular series, widely spaced from each other; single inner tubercle per plate; pores of a pair close together, oblique and separated by a wall. Interambulacra: Large areoles, above the ambitus separated by the scrobicular tubercles, becoming adorally confluent; median zone very narrow, set with a few small tubercles; median suture slightly depressed and forming



a narrow naked line; scrobicular tubercles only slightly larger than marginal tubercles. Primary spines: Long, slender, and gently tapering, shaft ornamented with low, longitudinal ridges set with fine, distally directed small thorns, especially on the adapical side of the spine; collar very long, about 8–9  mm; neck short; oral primary spines short, flattened, and curved inward, sides conspicuously serrated. Secondary spines: Scrobiculars long and flattened, some are slightly pointed, others may be more spatulate; marginal spines slightly shorter and narrower. Color: Test and secondary spines white, primary spines with white collar, the shaft becoming a deep pink. Distribution: Restricted to New Caledonia, 420 m deep. Histocidaris magnifica Mortensen, 1928 (Fig. 4.68 E) Test: Almost globular; diameter may reach 77 mm. Apical system: Somewhat arched; ocular plates deeply notched at the distal edge, usually exsert. Ambulacra: Poriferous zone as broad as interporiferous zone, pores distinctly transversely elongated, marginal tubercles fairly regular, nearly in contact; inner tubercles more irregular. Interambulacra: Areoles transverse oval; upper and lower side being parallel; nearly confluent except the three uppermost; scrobicular tubercles rather prominent, extrascrobicular space scattered with only a few small tubercles, leaving a distinct naked median line, also along outer border. Primary spines: About 1.5, the diameter of test, not tapering, perfectly smooth and shiny; oral primaries curved, strongly serrate, ending abruptly. Secondaries: Scrobicular spines long, broad, and excavated distally; marginal spines long, very slender. Color: Test and secondary spines more or less dark brown, primary spines white beige with a darker collar. Distribution: The species is recorded from the Philippines at a depth of about 200 to 300 m. Histocidaris nuttingi Mortensen, 1926 Test: Broad and flattened aborally, outline round. Apical system: Quite flat, tubercles abundant, most dense around the genital pores. Ambulacra: Marginal tubercles in series, but there are larger tubercles alternating to both series in a zigzag pattern. Interambulacra: At the ambitus and below scrobicular tubercles crowding along the horizontal sutures; distinct space filled with extrascrobicular tubercles also on outer side of plates.

4.1.1 Order: Cidaroida Claus, 1880 

 131

Primary spines: Up to 4 times the test diameter; shaft smooth, shiny, and white with scattered thorns; in large specimens, the tips may be swollen or flared and ridged; ambital spines may be serrate; oral primaries are curved and strongly serrated. Large tridentate pedicellariae with three large, long, slender valves that are visible to the naked eye. Color: Usually, the test and the spines are white; in large specimens, the test may have a yellow brown tint. Distribution: Restricted to the Caribbean from Cuba to Antigua, Antilles, 320 to 415 m. Histocidaris purpurata Thomson, 1872 (Fig. 4.69) (synonym Poriocidaris purpurata Thomson, 1872) This species differs from the other Histocidarids in having only bivalved pedicellariae. The other species of Histocidaris have pedicellariae with 3 valves (tridentate); globiferous pedicellariae are lacking in all Histocidarids. The World Echinoid Database (2010) synonymized Poriocidaris with Histocidaris. Test: Flattened above and below; diameter may reach 70 mm. Apical system: Rather naked, usually some scattered tubercles around the pores in genital and ocular plates, ocular plates exsert; gonopores in females larger than in males. Ambulacra: Moderately sinuous, marginal tubercles in a uniform series, inner tubercles lacking or very scarce adapically; below the ambitus, there may be more often one or rarely two per plate; peristomial ambulacral plates internally prolongated as usual in histocidarids. Interambulacra: Aborally with large areoles, crowded scrobicular tubercles and a few extrascrobicular tubercles; below the ambitus, the areoles are proportionally smaller leaving more space for more densely set secondary tubercles. Primary spines: 2–2.5 times the diameter; upper ones tapering; usually, there are longitudinal ridges of very fine spinules; sometimes, there may be a few well-developed thorns at the lower side of the shaft (more common in the eastern Atlantic); the neck may be conspicuously long and in some specimens even swollen; oral primary spines broad with blunt tip, finely serrate at the sides. Tridentate pedicellariae: With only two, strongly depressed valves. Color: The test and the secondary spines are very variable and range from white to dark brownish purple. Usually, the shaft of the primary spines is white, but the long collar shows the color of test and secondary spines. Sometimes, the mamelons of the tubercles may be rosy.

132 

A

 4.1 Subclass Cidaroidea Smith, 1984

B

D C

Fig. 4.69: Histocidaris purpurata. (A) Side view with spines, diameter of test 30 mm; northwest of Ireland. ZMH. The shaft of some of the primary spines is basally set with a few small and sharp thorns. In the white colormorph, the primary spines are not thickened. (B) Aboral side with spines, diameter 51 mm; northeast Atlantic, west of Ireland. ZMH. The spines on the apical system are scarce. In the purple colormorph, the neck of the aboral primary spines is strongly thickened and deep purple. (C) Aboral side of test, diameter 48 mm; northeast Atlantic. (D) Aboral side with spines, test diameter 49 mm, longest spine, loose, 161 mm; Great Barrier Island, Auckland, New Zealand. Dredged at a depth of 800 m.

Distribution: The geographic range is discontinuous: it is recorded from west of Ireland to the Canary Islands and the Caribbean Sea. Bathymetric range 600 to 1,800  m. It also occurs around New Zealand, where it shows the two color variations as well. Reported from the Bay of Plenty, Kermadec Ridge, Hawke Bay, and Chatham Rise, often living on seamounts (Anderson in Tracey et al. 2011). Histocidaris recurvata Mortensen, 1928 Test: Maximum recorded diameter 48 mm. Slightly flattened above and below.

Apical system: 50 % of diameter, ocular plates all exsert. Ambulacra: Interporiferous zone twice the width of pore zone. Primary spines: Reaching 2.5 times the diameter; slender, cylindrical, not tapering, but slightly flaring at the tip and curved upward – at least ambital; flattened in the outer half or third; basal part set with rather coarse, not serially arranged thorns, mainly on the adapical side; the shaft has otherwise about 15 finely serrated ridges, the interspaces of which are finely striated; milled ring rather prominent.

4.1.1 Order: Cidaroida Claus, 1880 



A

 133

B

Fig. 4.70: Histocidaris variabilis. (A) Oral side with some remaining spines, test diameter 60 mm; Hawaii, USA. ZMUC. (B) Aboral side. The gonopores of the female are large.

Color: Skin of test, collar of primary spines and secondary spines brown; shaft of primaries white. Occurrence: Holotype recorded from the Kei Islands, Indonesia. Depth 984 m. Histocidaris sharreri A. Agassiz, 1880 Test: Almost globular, apical system raised. Ambulacra: Marginal series of tubercles fairly regular, midzone rather naked, may be sunken. Interambulacra: Scrobicular ring prominent and crowded at the horizontal suture, extrascrobicular zone narrow, especially on outer side of plates. Primary spines: Length about 1.5 the test diameter, rarely showing thorns; tips ridged and flaring; ambital spines with two rows of serrations, which become progressively more distinct adorally; oral spines curved; thorns on the shaft may be well developed or lacking. Large tridentate pedicellariae have triangular, broad valves, which are visible to the naked eye. Color: The test is brown with yellow; the primary spines are white with a yellow brown collar. Distribution: Off Nevis and Antigua, Lesser Antilles; found only at 570 m, but supposed to occur in other depths too (Phelan 1970). Histocidaris variabilis A. Agassiz & H. L. Clark, 1907 (Fig. 4.66, 4.70) Test: Maximum recorded diameter of test 85 mm. Of larger specimens globular, in smaller specimens lower and rather flattened above.

Apical system: Relatively numerous tubercles are usually scattered over the whole of the apical plates. Ambulacra: In width, ca. 21–23 % of interambulacra; marginal tubercles regular, not contiguous, inner series of tubercles more or less regular. Interambulacra: Up to 10 plates per column; extrascrobicular tubercles rather numerous, leaving no distinct bare median space. Primary spines: In smaller specimens, 3 times the horizontal diameter; in large specimens, hardly reaching the diameter; cylindrical, the point somewhat fluted in subambital spines; set with numerous fine longitudinal, finely serrated ridges; oral primaries rather coarse. Scrobicular spines: Flattened, slightly excavate; marginal ones very slender. Color: Test and secondary spines brown to dark violet or deep purple, tip of ambital secondary spines with a green tinge; primary spines white with brown tip, collar brown or salmon colored. Distribution: This species is restricted to the waters around Hawaii. Depth range 320 to 555 m.

4.1.1.3 Family Psychocidaridae Ikeda, 1936 Coarse primary spines with club-shaped shaft; no interradial plates on peristome; tubercles generally without perforation. Only a single extant genus with one species.

134 

 4.1 Subclass Cidaroidea Smith, 1984

Smith (2004) has included Psychocidaris as a subgenus in Tylocidaris, a genus that lived in the Upper Cretaceous. It is characterized by broad, club-shaped primary spines and non-perforated tubercles. Psychocidaris ohshimai is the only surviving species of this ancient group.

Genus Psychocidaris Ikeda, 1935 Psychocidaris ohshimai Ikeda, 1935 (Fig. 4.71) Test: Flattened above and below; diameter may reach 35 mm. Tubercles: Not perforated, sometimes rudimentary perforation in the adapical tubercles; not crenulated.

A

C

B

D

Fig. 4.71: Psychocidaris ohshimai. (A) Aboral side with spines, diameter of test 32 mm; Bonin Islands, Japan. The primary spines are broad and strongly club-shaped. They are here strongly gnawed by predators, the uppermost being lost. (B) Oral side: the ambital primary spines become gradually more ridged; the adoral ones are short and simple. (C) Close-up of apical part: the tubercles are not perforated. (D) Oblique view of denuded test, diameter 27 mm; Mindanao, Philippines (photo by W. Clarenbach).



Apical system: Larger than peristome; ocular plates exsert; all plates densely tuberculated. Ambulacra: Narrow; pore pairs not conjugate, closely spaced; each pair separated from the next by a conspicuous wall; rows of marginal tubercles and two, slightly smaller inner ones very regular. Interambulacra: Areoles deepened, subambitally contiguous; scrobicular tubercles differentiated, extrascrobiculars uniform and densely set, sutures not at all marked. Peristome: Only ambulacral plates present; in outer part, biserially arranged. Primary spines: At aboral side, strongly club-shaped; at the ambitus, more flattened and sculptured with irregular thorns on the upper side, the underside with ridges; directed downward; oral spines short and slender, distally with ridges. Secondary spines: Flattened, scrobiculars only slightly longer than marginal ones. Distribution: Recorded from the Bonin Islands, south of Japan, and the Philippines.

4.2 Subclass Euechinoidea Bronn, 1860 The subclass Euechinoidea includes the small group of Echinothurioids and the Acroechinoidea, which comprises all other non-cidarid regular and irregular sea urchins.

4.2.1 Order Echinothurioida Claus, 1880 The echinothurioids have been known since the Middle Jurassic, but the fossil record is extremely poor because the thin plates do not favor preservation. Yet it was a test fragment from the Upper Cretaceous of England, which was first described as Echinothuria Woodward, 1863. Only some years later, extant echinothurioids were found in deeper water by the “Challenger” expedition. Now extant echinothurioids are known to exist from the Arctic through the Tropics to the Antarctic. The group is monophyletic. Echinothurioids are characterized by the following features: Test: Very low plates being flexible and imbricating; more or less conspicuous membranous spaces between the plates; width of ambulacra and interambulacra of about the same range. Apical system: Monocyclic in adults; the plates being often disassociated lying on a membrane.

4.2.1 Order Echinothurioida Claus, 1880 

 135

Ambulacra: Pattern of compound plates as repeating units of three, one primary and two demi-plates which are mostly occluded from the vertical sutures (Fig. 4.72 A); ambulacral plates continuing onto the peristome (only Kamptosoma has buccal plates). Tubercles: Perforated and non-crenulate (except in Kamptosoma). Jaw apparatus: With open foramen and grooved teeth (as in cidarids). Secondary spines: With venomous glands aborally. Due to special muscles, the echinothurioids are able to inflate their tests or to flatten them. Dead tests are usually collapsed, and the plates irregularly broken, so they seldom show the natural appearance. They are equipped with poison glands at their aboral spines. In some genera, the oral spines end in a veritable hoof; in others, they are simpler and covered in a skin sheath. With these specialized spines, the sea urchins move forward rather swiftly across soft bottoms. Most of the echinothurioids are deep sea forms. But some genera have secondarily wandered into reef environments in shallower water, becoming more tolerant of higher temperatures. The members of the genus Asthenosoma live in very shallow water, sometimes lying half dry at low tide. As they have very effective venomous spines at the upper side, they are feared by divers and fishermen. Sometimes the podia in the demi-plates or those in the primary plates may be reduced, for example in some species of Phormosoma, Hemiphormosoma, and Tromikosoma. In Kamptosoma asterias, the upper demi-plate is totally lacking on most of the aboral side. The development of the Echinothurioida is lecithotrophic, which means the females release large, yolky eggs, about 1  mm in diameter, that develop without a larval stage or metamorphosis. The sexes show no dimorphism, or only very slightly, the genital pores of males and females being equal. The order Echinothurioida contains three extant families: Kamptosomatidae: The family consists of a single genus that is unique in having only one demi-plate to each primary plate in the ambulacra. Phormosomatidae: Four genera are included in this family, in which the oral spines are simple or distally covered in a thick bag of skin. Echinothuriidae: The family consists of seven genera, in which the oral primary spines end in a distal hoof. Literature: Mortensen 1903, 1934, 1935; Emson & Young 1998; Mironov 1981, 2000; Mooi et al. 2004; Pierrat et al. 2006; Kroh & Smith 2010; Anderson 2013.

136 

A

 4.2 Subclass Euechinoidea Bronn, 1860

C

B

D

E

F

Fig. 4.72: (A–D) Typical characteristics of echinothurioida. (A) Generalized ambulacral plates: to each primary plate an adoral and an adapical demi-plate (or secondary plate) is associated. The demi-plates mostly do not reach the vertical sutures (one triplet in each column is shaded). (B, C) Araeosoma leppienae. (B) Aboral ambulacral plates. (C) Aboral interambulacral plates: the plates are connected by a leather-like membrane. Modified after Anderson 2013. (D) Asthenosoma varium: internal view of test. By means of the fan-like vertical muscles, reaching from the auricles to the apical system, the echinothurioids can inflate their tests or flatten them. Sarasin (1888), no scale stated. (E, F) Points of oral primary spines serving for locomotion. (E) Phormosoma bursarium with a distally inflated skin sheath. (F) Araeosoma violaceum with a hoof. (G, H). Aboral secondary spines with poison glands serving for defense. (G) Araeosoma thetidis with a small venomous gland. (H) Asthenosoma varium with a strongly inflated venomous gland. No scale stated (Mortensen 1935).

4.2.1.1 Family Kamptosomatidae Mortensen, 1934 The single genus is unique in the Echinothurioida in having five buccal plates, crenulate tubercles and only one demi-plate to each ambulacral primary plate. Genus Kamptosoma Mortensen, 1903 Kamptosoma asterias A. Agassiz, 1881 (Fig. 4.73 A, B) Test: Low hemispherical, diameter may reach up to 49 mm. Apical system: Ocular plates narrow and elongated, genital plates small and more or less subdivided; madreporite with few pores only. Ambulacra: Wide; on the aboral side, one of the two demi-plates in each triple set is absent, except nearest to the apical system; only the lower demi-plate is present and carries a well-developed tube foot; in the primary plate, the podium may also be reduced. Interambulacra: On the oral side, distally, two very conspicuous series of large primary tubercles, which are distinctly crenulate; on the upper side, each plate is set with

several rather small, not crenulated tubercles arranged like a slight arch. Peristome: Five large, well-developed buccal plates each carrying a podium, at the distal edge some additional plates without podia. Spines: Hollow, long, and slender, but exceedingly delicate and fragile; aboral spines with venomous gland distally. Distribution (including Kamptosoma abyssale: Mironov 1971): Central and northwest Pacific, Chile, and Antarctica, Tasman Sea between Australia and New Zealand, Madagascar. Bathymetric range 3,890 to 6,235 m. Kamptosoma is reported to sting severely and lingeringly as other echinothurioids (Mooi et al. 2004).

4.2.1.2 Family Phormosomatidae Mortensen, 1934 The family is characterized by oral primary spines, which are either simple or distally covered in a thick skin-bag serving for movement over soft substrata. Some of the aboral primary spines may be enveloped by a broad, leaf-like skin.

4.2.1 Order Echinothurioida Claus, 1880 



A

B

C

D

E

F

G

 137

Fig. 4.73: (A, B) Kamptosoma asterias. (A) Oral side, diameter 39 mm; Tasman Sea, 4,800 m. ZMUC. (B) Aboral ambulacral plates: (a) exterior view and (b) interior view (enlarged and mirrored). Modified after Mooi (2004) and A. Agassiz (1904). (a) In the lower plates, the adoral demi-plate has disappeared. One triplet of plates (above) and one doublet (below) are shaded. Scale: 5 mm. (b) The radial canal of the water vascular system leads up to the pore in the ocular plate (opl) along the median suture of the inner side (half-diagrammatic). Lateral canals connect it with the podial pore in each plate. Near the apical system (above), the primary plate and the adapical and adoral demi-plate are joined to the vessel, but in the lower plates, the adapical demi-plate in each plate set is not developed and the lateral canal ends blind (shaded spot). (C–E) Hemiphormosoma paucispinum. (C) Oral side; largest diameter 50 mm; Philippines. ZMUC ECH 490. On the distal part of the test, tubercles with large areoles occur. (D) Aboral ambulacra: the pore pairs in the primary plates are small in contrast to those in the demi-plates. (E) Oral ambulacra: the pore pairs in the demi-plates are very small and entirely lacking in the primary plates. Pores in red. Scale: 4 mm (Mortensen 1935). (F, G) Paraphormosoma alternans. (F) Ambulacral plates on the aboral side: the primary plates in each triplet are occluded from the outer suture; the demi-plates being continuous. (G) Ambulacral plates on the oral side. Scale: 4 mm (Mortensen 1935).

138 

 4.2 Subclass Euechinoidea Bronn, 1860

Hemiphormosoma Mortensen, 1934: Deepened areoles only on the distal part of the oral side; monospecific. Paraphormosoma Mortensen, 1934: No deepened areoles, primary tubercles in regular series on the oral and aboral side; monospecific. Phormosoma Thomson, 1872: Areoles deepened on the oral side; four species. Genus Hemiphormosoma Mortensen, 1934 Characterized by large tubercles and areoles restricted to the distal part of the oral side. Hemiphormosoma paucispinum Mortensen, 1934 (Fig. 4.73 C–E) Test: Very delicate, circumference distinctly pentagonal, diameter up to 62 mm. Apical system: Genital and ocular plates small and widely separated, periproctal plates small and numerous, scattered over the membrane. Ambulacra: Aborally, the demi-plates are positioned in the middle of the plates; on the oral side, more on the outer part, usually not reaching the suture; tube feet of the oral primary plates may be more or less reduced; well-developed tubercles and areoles only on the distal plates of the oral side. Interambulacra: Well-developed, large oral tubercles and areoles confined to the two distal-most plates. Peristome: Buccal notches and sacs strongly developed. Spines: Apparently smooth; ending in a sharp point, enclosed by a fleshy sac. Distribution: This species is known from the Sulu Sea at a depth of 4,095 m. Genus Paraphormosoma Mortensen, 1934 The genus is characterized by having continuous series of demi-plates along the outer edge of the aboral ambulacral plates. Paraphormosoma alternans de Meijere, 1902 (Fig. 4.73 F, G) Test: Low hemispherical, ambitus rounded, can grow to a large size. Apical system: Small, genital plates hardly protruding into the interambulacra, separated from the ocular plates by one periproctal plate. Ambulacra: Continuous series of demi-plates at the outer part of the triplet, primary plates usually excluded from the outer suture; areoles not deepened orally. Interambulacra: On the oral side, up to three primary tubercles on each plate; on the aboral side, a series of primary tubercles, usually centrally situated on every other plate; areoles not deepened on oral side; numerous secondary tubercles. Spines: With conspicious longitudinal ridges.

Color: Light purple. Distribution: Malayan Archipelago, 700 to 860 m. Genus Phormosoma Thomson, 1872 The genus is characterized by its distinctly deepened areoles covering most of the oral side. The pattern of the apical plates is very variable. Phormosoma consists of four species: Phormosoma bursarium A. Agassiz, 1881. Indo-Pacific. Phormosoma placenta Thomson, 1872. Northern Atlantic. Phormosoma rigidum A. Agassiz, 1881. New Zealand. Phormosoma verticillatum Mortensen, 1904. Indian Ocean. Phormosoma bursarium A. Agassiz, 1881 (Fig. 4.72 E, 4.75 A, B) Test: Flattened, upper side low hemispherical, edge sharp, diameter up to 128 mm. Apical system: Very variable in the arrangement of plates on the membrane or degree of extension into the interambulacra. Ambulacra: Primary tubercles on the oral side in regular series of 5–6 with large and deep areoles, disappearing at the ambitus; primary areoles on the aboral side much less conspicuous, series of tubercles irregular, adapically lacking; pore pairs on oral side in a straight series, demiplates at the outer suture; on aboral side, the pore pairs in arcs of three, forming a band, demi-plates mostly not reaching the vertical suture. Interambulacra: On the oral side, up to three primary tubercles in a horizontal series per plate, with large, deep areoles; on the aboral side, irregularly arranged primary tubercles only on distal part; around the whole margin, a distinct row of secondary tubercles. Peristome: Larger than apical system; membrane covered by wedge-shaped ambulacral plates; well-marked buccal notches and sacs. Spines: On the oral side, distally with a thick fleshy sac, strong muscles; aborally, more or less curved, some may be enveloped by a leaf-like skin; fringe spines coarse and set with rather dense thorns; longitudinal ridges. Color: In live specimens, apparently brownish to yellow orange; dead tests are faded out and usually beige. Biology: The species lives obviously on muddy bottom, where it moves rather swiftly on its club-shaped oral spines. Distribution: The species is spread over the entire IndoWest Pacific from Natal and the Arabian Sea to Japan, Hawaii, and New Zealand at a depth of 170 to 2,340 m. Remarks: Phormosoma bursarium resembles very much P. placenta. It differs by its larger size, its rounder margin, by the coarser tubercles around the margin, and by its geographic range.



4.2.1 Order Echinothurioida Claus, 1880 

 139

Remarks: This species resembles very much P. bursarium. It differs in having a smaller size, a distinctly sharper margin, and finer fringe tubercles, and further by its geographic range. Phormosoma rigidum A. Agassiz, 1881 Very similar to the other species of Phormosoma. It differs by the pore pairs being positioned aborally near the outer sutures the two outer pores being rudimentary. Recorded diameter of test 41 mm. Occurrence: New Zealand.

Fig. 4.74: Phormosoma placenta. Aboral side of test, diameter 68 mm; Davis Strait, northwest Atlantic. ZMUC.

Phormosoma placenta Thomson, 1872 (Fig. 4.74, 4.75 C–E) Test: Low, hemispherical with sharp margin; maximum diameter 90 mm. Ambulacra: Demi-plates on oral side at outer edge; on aboral side, more toward the middle of the plates; primary tubercles small and surrounded by large and deep areoles orally, aborally irregular and with areoles not deepened. Interambulacra: Areoles on oral side deepened, but not on aboral side. Peristome: Larger than apical system; covered by ambulacral plates; buccal slits distinct. Spines: No longitudinal ridges; primaries orally with fleshy sac; on upper side, very brittle; up to 20 spines provided with fleshy, leaf-shaped structures. Color: Yellow to brown. Distribution: This species lives in the northern Atlantic from Iceland and the Davis Strait southward to the West Indies and the Gulf of Guinea. A variety, P. placenta africana, is native to the west coast of South Africa, having a larger size. Bathymetric range 50 to 3,700 m. Biology: Emson & Young (1998) could observe in situ some specimens near the Bahamas by submersible: an array of vertically orientated fleshy primary spines covers either the whole aboral side in different arrangements or appears to form a “fence” along the periphery. The spines move passively in response to water currents. The oral primary spines end in a blunt fleshy sac adapted to walk on soft substrata without leaving any imprint in the sediment.

Phormosoma verticillatum Mortensen, 1904 (Fig. 4.75 F) Test: Maximum diameter may reach 60 mm. Apical system: Genital and ocular plates extending into the interambulacra; periproctal plates carrying tubercles. Ambulacra: On oral side, regular series of large primary tubercles, median space rather naked, only scattered with a few, small tubercles; tube feet of primary plates may be rudimentary; on aboral side up to three primary tubercles on each plate, pore pairs forming an arc. Interambulacra: As in P. bursarium, with up to three large tubercles on a plate with deepened areoles on the oral side; on the aboral side, fairly large tubercles on each plate. Spines: No longitudinal ridges; the thorns of the aboral spines arranged in whorls (verticillate). Color: Perhaps dark red (Döderlein 1905). Distribution: This species occurs in the entire Indian Ocean from off Natal (Phormosoma adenicum Döderlein, 1905 as synonym) to the Arabian Sea and in the Malayan Archipelago (Celebes) at depths of about 1,100 to about 1,900 m. Remark: The species differs from the three other species of Phormosoma by its verticillate spines.

4.2.1.3 Family Echinothuriidae Thomson, 1872a This family differs from the Phormosomatidae in having a distal hoof at the oral primary spines adapted for movements over soft bottom as well. The genera are difficult to distinguish. Because the tests are mostly collapsed and the plates are often broken and folded, the sutures being almost invisible. Even more difficulties exist in the distinction of the species. Mortensen mostly used the shape of the pedicellariae to distinguish them. They live, with the exception of the species of Asthenosoma, in deeper to abyssal waters. Araeosoma Mortensen, 1903. Nineteen species. Asthenosoma Grube, 1868. Six species. Calveriosoma Mortensen, 1934. Two species. Hapalosoma Mortensen, 1903. Three species. Hygrosoma Mortensen, 1903. Three species.

140 

 4.2 Subclass Euechinoidea Bronn, 1860

A

D

B

E

C

F

Fig. 4.75: (A, B) Phormosoma bursarium. (A) Aboral side with spines, diameter of test 113 mm; east of Zamboanga, Philippines. ZMUC. (B) Oral side. (C–E) Phormosoma placenta. (C) Oral side, diameter 68 mm; Davis Strait, northwest Atlantic. ZMUC. Both sides look very different: aborally with small primary tubercles and indistinct areoles; orally with the large primary tubercles surrounded by wide, depressed areoles. (D) Ambulacral plates on the aboral side. (E) Ambulacral plates on the oral side. Scale: 5 mm (Mortensen 1935). (F) Phormosoma verticillatum. Oral side of test, diameter 60 mm; Bay of Bengal. ZMUC ECH 54.

Sperosoma Koehler, 1897. Ten species. Tromikosoma Mortensen, 1903. Six species. Genus Araeosoma Mortensen, 1903 Test: Large and low hemispherical or cushion-shaped. Apical system: Ring of ocular and genital plates contiguous; genital pores open in elongated membranous gaps outside the genital plates. Ambulacra: Demi-plates fully occluded, pore pairs forming three vertical series. Interambulacra: Coronal plates very narrow; conspicuous membranous interstices especially on the aboral side; oral primary tubercles forming very regular series, positioned at the very outer edge (adradial). Peristome: Usually, the pore pairs on the peristome occur in double rows. Pedicellariae: The species of Araeosoma are unique in having dactylous pedicellariae with well-developed valves.

The genus consists of 19 extant species: Araeosoma alternatum Mortensen, 1934. Western Indian Ocean. Araeos oma anatirostrum Anderson, 2013. New Zealand and southeastern Australia. Araeosoma bakeri Anderson, 2013. Northern New Zealand. Araeosoma belli Mortensen, 1903. West Indies. Araeosoma bidentatum Anderson, 2013. New Zealand. Araeosoma coriaceum A. Agassiz, 1879. Indo-Pacific. Araeosoma eurypatum A. Agassiz & H. L. Clark, 1909. Galapagos Islands. Araeosoma fenestratum Thomson, 1872. Northeastern Atlantic. Araeosoma leppienae Anderson, 2014. Auckland Islands, south of New Zealand. Araeosoma leptaleum A. Agassiz & H. L. Clark, 1909. Panama, Galapagos Islands. Araeosoma migratum Anderson, 2013. New Zealand and southeastern Australia.



Araeosoma owstoni Mortensen, 1904. Western Pacific Ocean. Araeosoma parviungulatum Mortensen, 1934. Sulawesi, Indonesia. Araeosoma paucispinum H. L. Clark, 1924. Western Indian Ocean. Araeosoma splendens Mortensen, 1934. Kei Islands, Indonesia. Araeosoma tertii Anderson, 2013. Northern New Zealand. Araeosoma tesselatum A. Agassiz, 1879. Philippines, China Sea. Aaeosoma thetidis H. L. Clark, 1909. Eastern Australia, New Zealand. Araeosoma violaceum Mortensen, 1903. Northeast Atlantic. Araeosoma alternatum Mortensen, 1934 Main characteristics of genus. Adradial primary tubercles in oral interambulacra on every second plate, series continues well onto aboral side; hoof small and flaring. Distribution: Western Indian Ocean, recorded depth 1,289 m. Araeosoma anatirostrum Anderson, 2013 Main characteristics of genus. Test diameter up to 135 mm. Ambitus distinctly rounded. Interambulacra: Membranous interstices rather narrow, wider on the oral side; columns of aboral interambulacral plates strongly angled to each other, especially adapically fitting around the elongated genital plates; adradial primary tubercles on oral side on every plate. Spines: Very fragile, mostly lost or broken. Tridentate pedicellariae with conspicuous duck-billshaped valves, dactylous pedicellariae not found. Distribution: Recorded from around New Zealand and off southeastern Australia, potential depth range 990 to 1,251 m. Araeosoma bakeri Anderson, 2013 Test: Diameter of subpentagonal test may reach 152 mm. Interambulacra: Columns of aboral interambulacral plates strongly angled to each other, especially adapically fitting around the elongate genital plates; areoles large and overlapping; oral adradial primary tubercles on every plate. Spines: Oral primaries end in an extremely short hoof. Color: Test and spines black violet. Distribution: The species is recorded from northern New Zealand, with a maximum on seamounts in the Bay of Plenty. Potential depth range 180 to 375 m.

4.2.1 Order Echinothurioida Claus, 1880 

 141

Araeosoma belli Mortensen, 1903 Test: Diameter may reach 140 mm. Spines: Hoof of oral primary spines large and conical; aboral spines with fleshy tips. Three kinds of tridentate pedicellariae. Color: Live specimens are deep claret. Distribution: Caribbean Sea. Depth range 130 to 1,020 m. Biology: Observations in situ by Emson & Young (1998) near the Bahamas showed that the upper primary spines provided with a fleshy tip (“flag spines”) respond actively to disturbances by erection or bending to the side (compared with Phormosoma placenta). The oral spines ending in a hoof are adapted for quick movement on soft bottom in a coordinated mode. Araeosoma bidentatum Anderson, 2013 Test: Diameter may reach 138 mm. Interambulacra: Membranous spaces rather narrow, widest aborally; adradial oral primary tubercles on every plate. Spines: Delicate and mostly lost; hoofs white and short, narrower than spine, not flared. Pedicellariae: The typical bidentate ones abundant, dactylous ones with 5 valves. Color: Test and appendages deep red, peristome mustard yellow. The color retains in preserved specimens. Distribution: Found around New Zealand, depths at least 960 to 990 m. Araeosoma coriaceum A. Agassiz, 1879 (Fig. 4.76 C1, 4.77 A–C) Test: Slightly inflated at the upper and lower sides, subpentagonal; diameter may reach 190  mm, perhaps even 220 mm. Apical system: Genital and ocular plates subdivided in larger specimens; genital pores open in membranous gaps outside the genital plates. Ambulacra: Narrower than interambulacra; on the aboral side, some larger tubercles near the ambitus, decreasing in number adapically. Interambulacra: On oral side, each plate carries a primary tubercle, which form a very regular series, also irregular rows near the midline; small tubercles very numerous; aboral side in the whole rather naked, primary tubercles irregularly scattered, several small tubercles. Peristome: Double series of pore pairs, buccal sacs small. Spines: Primaries at oral side curved, hoof very small. Color: In live specimens, the test is greenish black or dark brown and the spines are also dark. Distribution: The species is known in the Indo-Pacific at depths of 360 to 720 m.

142 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

epidermis

calcareous valves

gland

C

4

F

1 2

3 stalk

Fig. 4.76: In all species of echinothuriids, the oral primary spines are equipped with a distal hoof. (A) Hoofs (arrows) on the oral side of Asthenosoma varium. Scale: 10 mm. (B) Araeosoma violaceum, dactylous pedicellaria: the 4 valves are very slender, ending distally in a spoon-shaped structure. These pedicellariae occur mainly on the oral side near the ambitus. In other species of Araeosoma, the dactylous pedicellariae may carry 3 or 5 valves. Scale: 1 mm (Mortensen 1935). (C) Distal end of oral spine: (1) Araeosoma coriaceum, (2) Araeosoma fenestratum, (3) Calveriosoma hystrix, and (4) Hygrosoma luculentum. Scale: 2 mm (Mortensen 1935).

Araeosoma eurypatum A. Agassiz & H. L. Clark, 1909 Main characteristics of the genus. Test: Recorded diameter about 140  mm. Mortensen emphasized that on the outer aboral side, the ambulacra are wider than the interambulacra. Interambulacra: Series of adradial primary tubercles on oral side on every plate, continuing also onto the aboral side almost to the apical system; membranous interstices inconspicuous on oral side but fairly distinct on aboral side. Sphaeridia: Strongly elongated resembling almost a spine. Occurrence: Found off the Galapagos Islands. Depth 1,227 m. Araeosoma fenestratum Thomson, 1872b (Fig. 4.76 C2, 4.77 D) Test: Round; in living specimens, low hemispherical; diameter may reach 180 mm. Apical system: Madreporite conspicuous and undivided; ocular plates rather large, remaining in contact with genital plates.

Ambulacra: Primary tubercles orally on each plate; usually of same size on both aboral and oral sides. Interambulacra: Adradial series of primary tubercles on oral side regularly on every plate, inner series more irregular; more tubercles exist around the ambitus. Peristome: With numerous low plates; plates in ambulacra with pore pairs distally in double series. Spines: Oral primary spines with thorny ridges; conspicuous, conical hoof; aboral primary spines with ridges. Color: Spines white, test dark purple to brown, fading out in alcohol. Distribution: Northern Atlantic from the Rockall Bank to Portugal and the West Indies. Bathymetric range 148 to 1,180 m. Araeosoma leppienae Anderson, 2013 (Fig. 4.72 B, C) Test: Diameter of holotype and sole specimen 118 mm. Apical system: Genital plate components not separated.

4.2.1 Order Echinothurioida Claus, 1880 



A

C

 143

B

D

Fig. 4.77: (A–C) Araeosoma coriaceum. (A) Aboral side of a young specimen without spines, diameter 84 mm; Negros, Philippines. There occur specimens with much greater than the double diameter. (B) Oral side. (C) Aboral side with spines, diameter 91 mm; Negros, Philippines. (D) Araeosoma fenestratum. Aboral side of test, buffered, diameter 115 mm; west coast of Ireland. ZMUC.

Interambulacra: Adradial series of primary tubercles on oral side on every plate. Pedicellariae: Large tridentate ones with broad, coarsely serrated valves, dactylous pedicellariae with 6 valves. Color: Test and spines are dark and light brown in radiating stripes, which may be influenced during capture. Occurrence: Found on Christabel seamount, west of the Auckland Islands, south of New Zealand. Depth 968 to

973  m. It is very likely that this species occurs generally along other sub-Antarctic ridges and seamounts. Araeosoma leptaleum A. Agassiz & H. L. Clark, 1909 Maximum recorded diameter 125 mm. Hoof of oral primaries thickest at the base and pointed to the tip, looking inversely conical. Distribution: Panama, Galapagos Islands, 612 to 2,003 m.

144 

 4.2 Subclass Euechinoidea Bronn, 1860

Araeosoma migratum Anderson, 2013 Diameter up to 166 mm. Apical system: Distal elements of genital plates tend to migrate into the midline of interambulacra. Interambulacra: Membranous spaces distinct, especially on oral side and in interambulacra; adradial series of oral primary spines on every plate. Spines: Very delicate, hoofs white, short and flaring. Pedicellariae: Large, involute tridentate ones with a long, narrow, and curved blade; the tip slightly widened. Distribution: Found around New Zealand and off south­ eastern Australia at a depth of 614 to 949 m. Araeosoma owstoni Mortensen, 1904 Test: Round and low hemispherical; maximum diameter may reach 150 mm. Apical system: Extension of genital plates into the interambulacra and the position of the genital pores very variable. Ambulacra: Demi-plates may be placed nearer to the inner or to the outer suture, always forming three distinct series of pore pairs. Interambulacra: Adradial series of primary tubercles usually regular; inner series more irregular; membranous interstices broad. Peristome: Rather small; ambulacral plates with pore pairs distally in double series. Spines: Aboral spines between 20 and 35 mm, hoof short. Color: In live specimens, the test is grayish pink to red. The aboral spines are light green; on the oral side, the spines are white, sometimes banded. Biology: Araeosoma owstoni is reported to be a voracious echinoid. Distribution: The species lives in the western Pacific Ocean from Japan to Australia and Tasmania at depths of 70 to 210 m. Literature: Shigei 1986; Rowe & Gates 1995. Araeosoma parviungulatum Mortensen, 1934 Test: Diameter of holotype 170  mm. Subpentagonal, corners in swollen ambulacra. Interambulacra: On the oral side, a regular series of adradial tubercles on every plate and another regular series in the median part; one large tubercle to every second plate; plates downward curved. Pedicellariae: Dactylous ones with 5 valves, two kinds of tridentate ones, triphyllous one with very slender valves. Color: Uniform dark gray. Occurrence: Butung Strait, Sulawesi, Indonesia. Depth 377 m.

Araeosoma paucispinum H. L. Clark, 1924 (Fig. 4.78) Test: Slightly pentagonal, low hemispherical; maximum diameter reaching 135 mm. Apical system: Plates small and wide spaced; madreporite often divided into two or more parts; genital plates do not extend far into the interambulacra. Ambulacra: Much narrower than interambulacra; primary tubercles on oral side fairly regular, aboral tubercles smaller, irregular, and more numerous. Interambulacra: Primary tubercles on oral side on every plate, forming regular series; on aboral side, the primary tubercles are smaller and irregularly arranged; on both sides, many smaller tubercles. Peristome: The double series of pore pairs near the peristomial edge is usually very distinct; buccal sacs small. Spines: On the oral side, the primaries are moderately long and curved; the conspicuously white hoof is long and slender; on the aboral side, the spines are straight, forming a dense, uniform covering. Color: Both test and spines are dark violet, more rarely red violet. Distribution: The species is found off the east coast of South Africa. Bathymetric range about 380 m. Araeosoma splendens Mortensen, 1934 Test: Diameter of holotype 115 mm. Interambulacra: Adradial series of oral primary tubercles on every plate, plates not flexuous. Pedicellariae: Dactylous ones with 4 valves. Color: Both test and spines are of a splendid red, a little less intense on the oral side. Cleaned tests are white. Occurrence: Kei Islands, Indonesia, 300 m. Araeosoma tertii Anderson, 2013 Test: Diameter of test up to 170 mm. Interambulacra: Membranous interstices conspicuous; oral adradial series of primary tubercles on every plate; a few large primary tubercles on aboral side. Pedicellariae: Large tridentate ones with broad, coarsely serrated valves; dactylous ones not found. Color: Test and appendages deep red. Distribution: Found on knolls in the Bay of Plenty, New Zealand, and off Norfolk Island. Depth range at least 180 to 260 m. Araeosoma tesselatum A. Agassiz, 1879 (Fig. 4.79 A, B) Test: Rather tough, often preserved in good shape, diameter may reach 140 mm. Apical system: Dissolved plates, madreporite usually subdivided; membranous prolongation of genital plates large.

4.2.1 Order Echinothurioida Claus, 1880 



A

 145

B

D

C

Fig. 4.78: (A–C) Araeosoma owstoni. (A) Aboral side with spines, diameter 85 mm; Shimizu, Central Japan. (B) Aboral side of test, diameter 165 mm; Korea Strait. ZMUC. (C) Close-up of upper ambulacrum. Scale: 5 mm. (D) Araeosoma paucispinum. Aboral side of test, diameter 135 mm; South Africa. ZMUC.

Ambulacra: Much narrower than interambulacra; on oral side, a few large tubercles more or less near the midline; aborally, some much smaller primary tubercles forming no series. Interambulacra: On oral side, every plate carries a large primary tubercle forming very regular series along the edge of the outer suture, the areoles are elliptical occupying the whole height of the plate, on the distal part there are also some large tubercles on every second plate more or less near the midline, the rest of the plates is densely covered by small tubercles. Spines: Oral primaries slender and curved, hoofs small and conical; aboral spines straight.

Color: On the upper side, the dark membranous interstices and the dark midline contrast distinctly against the light plates, giving the columns a ladder-like pattern. Distribution: The species occurs throughout the entire Malayan Archipelago at depths of 180 to 900 m. Araeosoma thetidis H. L. Clark, 1909 (Fig. 4.72 G, 4.79 C) Test: May reach a maximum diameter of 200 mm. Apical system: In young specimens, compact; in larger tests, the plates are more dissolved and the genital pores are surrounded by a membranous space of varying size. Ambulacra: Fairly large tubercles in the pore zones; demi-plates small.

146 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C D

Fig. 4.79: (A, B) Araeosoma tesselatum. (A) Close-up of aboral side, buffered, diameter of test 109 mm; Kei Islands, Indonesia. ZMUC. (B) Oral side. (C) Araeosoma thetidis. Oral side, partly with spines, diameter of test 86 mm. East coast of Australia. ZMUC. (D) Araeosoma violaceum. Aboral side of test, diameter 124 mm; Porcupine Bank, southwest of Ireland. ZMUC.

Interambulacra: Oral side with a row of large tubercles on every second plate along the outer edge, alternating with a series of large tubercles more medially; sometimes one plate may carry tubercles of both series. Color: Live specimens show a striking appearance: the test is a deep red with vivid white naked regions, creating a pattern of 20 radiating stripes. Preserved specimens fade out to a dark red brown or a dull fawn; the aboral spines usually with a tint of green. Distribution: This species is found along the east coast of Australia southward to the Bass Strait and off New

Zealand (mainly on knolls in the Bay of Plenty) at depths of about 70 to 400 m. Remarks: Only in A. alternatum and A. thetidis, the large oral tubercles occur alternately on every second plate. Araeosoma alternatum has no larger tubercles in the pore zones, whereas in A. thetidis there are larger tubercles in the pore zones. Araeosoma violaceum Mortensen, 1903 (Fig. 4.72 F, 4.76 B, 4.79 D) Test: Distinct membranous space between peristomial plates and coronal plates.



Apical system: Broad prolongations of genital plates extend into the interambulacra. Aboral ambulacra: Close to the apical system abruptly reduced in width. Dactylous pedicellariae: With 4 valves. Distribution: Northern Atlantic from the Rockall Bank to Portugal and from the Denmark Strait to the West Indies. Depth range at least 340 to 900 m. Genus Asthenosoma Grube, 1868 The genus is characterized by the lack of larger primary spines (respectively tubercles) on the aboral side; secondary spines covered by a skin sheath and equipped with poison glands distally. Test: Very large, can reach 230 mm in diameter; more or less broad membranous gaps between the columns in ambulacra and interambulacra. Apical system: Large, in adult specimens, monocyclic and somewhat dissolved; the long, conspicuous madreporite extending more or less into the interambulacra. Ambulacra: Pore pairs in three dense series; plates extremely low and numerous; tubercles not forming regular series; 2 to 3 primary tubercles per plate on oral side, none on aboral side. Interambulacra: Plates extremely low and numerous, primary tubercles on the oral side more or less irregular, up to five per plate, continuing a little above the ambitus, then disappearing aborally. Spines: Hollow, primaries on the oral side curved, serrate and ending in a distal hoof; aboral venomous secondary spines short and thin. There are six extant species of Asthenosoma: Asthenosoma dilatatum Mortensen, 1934. Jolo, Philippines. Asthenosoma ijimai Yoshiwara, 1897. Indo-West Pacific. Asthenosoma intermedium H. L. Clark, 1938. North­eastern Australia. Asthenosoma marisrubri Weinberg & De Ridder, 1998. Endemic to the northern Red Sea. Asthenosoma periculosum Endean, 1964. North­ eastern Australia. Asthenosoma varium Grube, 1868. Widespread in the Indo-Pacific. Asthenosoma dilatatum Mortensen, 1934 Only two young specimens of 20 and 10  mm are recorded. They differ by the shape of the very conspicuous tridentate pedicellariae: 1–1.5 mm length of head, valves broad, simply leaf-shaped, and of very delicate structure. Occurrence: Off Jolo, Philippines. Depth 38 m.

4.2.1 Order Echinothurioida Claus, 1880 

 147

Asthenosoma ijimai Yoshiwara, 1897 (Fig. 4.80 A) Test: Diameter of test may reach 140 mm. Apical system: Madrepores distributed over the adjacent periproctal or ocular plates. Oral primary spines: Ending in a slender hoof; they are not banded as in A. varium. Aboral secondary spines: Short and invested in a skin sheath, which is annularly constricted the protuberances being filled with venom. The pigment in the venomous liquid is bright reddish brown or purplish, giving the spine a banded appearance. Some of these secondary spines occur also on the oral side. Color: The test is usually more or less uniformly yellowish brown. Distribution: Widely spread in the Indo-West Pacific from the Maldives to Hawaii and from Sagami Bay, Japan, to northwest Australia, at depths of 8 to 300 m. Remark: Asthenosoma ijimai differs from A. varium by the extension of its madreporic pores. In A. varium, the pores are confined to the madreporite itself, may it be one plate in smaller specimens or divided in up to three parts in larger one. Asthenosoma intermedium H. L. Clark, 1938 Only two specimens were found, 90 and 120  mm in test diameter. The species is characterized by more numerous and extremely low plates in each column of ambulacra, but fewer plates in interambulacra than in A. varium. Oral primary tubercles in ambulacra tend to form series. Only tridentate pedicellariae with rather elongate heads, the valves up to 2 mm in length. Color: Deep brown with a purplish tint, spines light green, with bands at least near the tip. Occurrence: Northeastern Australia, 0 to 72 m. Asthenosoma marisrubri Weinberg & De Ridder, 1998 (Fig. 4.80 B, 4.81 A) Asthenosoma marisrubri has been separated from A. varium only recently (Weinberg & De Ridder 1998). Former descriptions of A. varium relied often on populations from the Red Sea – and that means on specimens of A. marisrubri, in scientific as well as in popular publications. Main differences between A. marisrubri and A. varium: In A. marisrubri, the aboral secondary spines with blisterlike poison glands at the distal end are larger and distributed more uniformly over the upper surface. In A. varium, the spines with venomous blisters are smaller and mostly confined to the borders of approximately rectangular patches separated by naked areas. The spines invested by a thick skin sheath but without a distinct distal poison gland, common in A. varium, do not occur in A. marisrubri

148 

 4.2 Subclass Euechinoidea Bronn, 1860

D

A B

E

D

C

F

Fig. 4.80: (A) Asthenosoma ijimai. Aboral side of test, diameter 148 mm; Jolo, Philippines. ZMUC. (B) Asthenosoma marisrubri. Venomous secondary spine on the aboral side with a blister-like poison gland at the distal end. (C–F) Asthenosoma varium. (C) Large secondary spine invested in a thick skin sheath annularly constricted and filled with venom. These spines are arranged in approximately rectangular areas. This kind of spines is lacking in A. marisrubri. (D) Small secondary spine with a distal blister-like poison gland. These spines border the rectangular areas set with the large secondary spines. Scale: 3 mm (modified after Weinheim & De Ridder 1998). (E) Aboral side with spines, diameter of test 207 mm; Negros, Philippines. (E) Close-up of aboral side with spines: the plates are extremely narrow. (F) Side view of young specimen in natural condition, largest diameter 61 mm; Abrolhos Island, Western Australia. The upper spines are very slender, those on the oral side more robust ending in hoofs.

(see Fig. 4.80 B, C). These features of soft tissue are not visible on dried specimens. Distribution: Asthenosoma marisrubri forms a distinctly separated population endemic to the northern Red Sea. The geographically nearest other Asthenosoma species occur around the Maldives and Ceylon. Asthenosoma periculosum Endean, 1964 This species differs from its congeners by having its adradial primary tubercles on the oral side in regular series and in possessing dactylous pedicellariae. Only

two specimens were found, with a test diameter of 87 and 83 mm. Color: Purplish brown to light brown. Occurrence: Northeastern Australia. Depth 86 m. Asthenosoma varium Grube, 1868 (Fig. 4.72 D, H, 4.76 A, 4.80 C–F, 4.81 B) Test: Very large, can reach 230 mm in diameter. Apical system: Large, in adult specimens, monocyclic and somewhat dissolved, the long, conspicuous madreporite extending more or less into interambulacra.

4.2.1 Order Echinothurioida Claus, 1880 



A

 149

B

Fig. 4.81: (A) Asthenosoma marisrubri. Hurghada, Egypt. The animal moves swiftly over corals. Its aboral surface is uniformly covered in venomous secondary spines. Each of it carries a blister-like distal poison gland (photo by H. and I. Rauch). (B) Asthenosoma varium. Lembeh Strait, Sulawesi, Indonesia (photo by R. Kraft). The blister-like secondary spines are distributed in more or less rectangular patches (see also Fig. 4.80 C).

Ambulacra: Pores in three dense series; plates very low and numerous; primary tubercles on oral side irregular. Interambulacra: Plates low and numerous, oral primary tubercles also irregular. Spines: Hollow, primaries on the oral side ending distally in a hoof, aboral secondary spines short and thin, with thick skin sheath, banded in darker pigment, developed more or less distinctly in rectangular areas and bordered by smaller spines with distal poison glands (compare A. marisrubri). Color: In life, very variable, but always bright and colorful: red with white poison glands or white with red pore zones, greenish or purplish The aboral spines are banded. The bare test is brown. Reproduction: The female of Asthenosoma varium releases large yolk-rich eggs, which develop after fertilization through an abbreviated larval stage to metamorphosis and settlement. Biology: This species is reported from shallow waters from the ebb line to depths of about 100 m; it can even fall half dry at low tide. The animals live on muddy grounds or between boulders of corals, where they graze on encrusting organisms, especially sponges from the surface of dead corals. Their locomotion is swift among the blocks of corals or on sandy flats, due to their hoof-like oral spines. They can creep through rather low rifts by changing the form of their test. The aboral spines with their poison glands are continuously moving like ears in a grain field. This species is observed to live together with diadematids under water-closet placed over the water, where they obviously partake of the rich food resource. Distribution: Asthenosoma varium is found in the IndoWest Pacific from Ceylon through the Malayan Archipelago

and from south Japan to northwest and north Australia and New Caledonia, at depths of 0 to 167 m. Remarks: Because Asthenosoma varium is very variable in color, distribution of oral primary tubercles, arrangement of apical plates, and extension of the naked areas even in a single individual, it is often difficult to distinguish the species. Genus Calveriosoma A. Agassiz, 1881 Calveriosoma is closely related to Araeosoma and Hapalosoma, but distinguished mainly by the shape of the pedicellariae. Typical for the genus is the red color of the test, which does not fade out in alcohol. Test: Low hemispherical or flat, circumference round, membranous interstices aborally very narrow, conspicuous only on oral side; very large forms. Apical system: Ocular plates large, in contact with genital plates; madreporite large, somewhat elevated, rarely subdivided. Ambulacra: Primary tubercles in nearly parallel, irregular longitudinal series almost from peristome to apical edge; sometimes, the secondary tubercles are hardly smaller; demi-plates far from outer suture; numerous small tubercles. Interambulacra: On oral side, a very regular series of primary tubercles close along the outer edge of the plates and a less regular row near midline; primary tubercles on aboral side irregular; numerous small tubercles. Peristome: Plates small and crowded, pore pairs distally in double rows. Spines: Hoof of oral primary spines small and flaring; aboral spines with poison glands.

150 

 4.2 Subclass Euechinoidea Bronn, 1860

Color: The skin of the test is reddish, remaining on dried and in alcohol preserved specimens, but well-cleaned tests are whitish. The genus consists of two species, which closely resemble each other: Calveriosoma gracile A. Agassiz, 1881. Indo-Pacific, 160 to 950 m. Calveriosoma hystrix Thomson, 1872. Northeastern Atlantic, 360 to 1,800 m. Calveriosoma gracile A. Agassiz, 1881 (Fig. 4.82 A) Test: May reach a diameter of 190 mm. The species differs from Calveriosoma hystrix by its yellow red to vermilion color and by its more or less conspicious naked areas on the aboral median line of both ambulacra and interambulacra. Distribution: The species occurs in the Indo-Pacific at depths of 160 to 950 m. Calveriosoma hystrix Thomson, 1872a (Fig. 4.76 C3, 4.82 B) Characteristics of the genus. The diameter may reach 160 mm, probably up to 240 mm. The species is distinguished from Calveriosoma gracile in having less conspicious naked median lines in both ambulacra and interambulacra on the aboral side. The color is a bright red, not vermilion as in Calveriosoma gracile. Distribution: This species is found in the East Atlantic from southwest Iceland to the Azores and Canaries at depths of 360 to 1,800 m. Genus Hapalosoma Mortensen, 1903 Test: Relatively small, flattened and, in living specimens, with a sharp edge; circumference rounded pentagonal Apical system: Genital plates with short membranous prolongations, pores large; ocular plates often larger than genital plates, forming a continuous ring; madreporite enlarged and inflated. Ambulacra: Pore pairs on both oral and aboral side in three rather close series, forming distinct arcs of three; orally, no primary tubercles; one demi-plate mostly in contact with the outer suture on oral side. Interambulacra: Aboral primary tubercles in a regular, oblique series; membranous interstices prominent. Peristome: Buccal sacs small, but distinct. Dactylous pedicellariae with three strongly developed glands and rudimentary valves. Spines: Oral primaries distally thickened with a more or less large hoof; aboral spines with poison gland. Literature: Shigei 1984; Rowe 1989; Anderson 2013. Four species are included in this genus:

Hapalosoma amynina Anderson, 2013. New Zealand. Hapalosoma gemmiferum Mortensen, 1934. Japan. Hapalosoma pellucidum A. Agassiz, 1879. Indo-Pacific. Hapalosoma pulchrum Rowe, 1989. Tasman Sea. Hapalosoma amynina Anderson, 2013 Test: Test diameter up to 115 mm. Circumference subpentagonal. Interambulacra: Adradial primary tubercles on every plate on oral side, continuing above the ambitus on 1–2 plates as the only aboral primary tubercles. Pedicellariae: Dactylous ones with 3 valves, small tridentate pedicellariae with long, narrow blades. Color: Test, spines, and tube feet show a brilliant red due to the pigment in the skin. The white hoofs are very conspicuous. On cleaned tests the membranous spaces are also white. Distribution: Trawled from some seamounts in the Bay of Plenty, New Zealand, and from the Norfolk Ridge, Tasman Sea. Most of the specimens (7 from 11) came from a single knoll. Hapalosoma gemmiferum Mortensen, 1934 (Fig. 4.82 C, D) Test: Diameter may reach up to 66 mm. Ambulacra: On oral side, one demi-plate is in contact with the outer suture. Interambulacrum: On oral side, primary tubercles arranged in a very regular series along the outer edge of the plates, much smaller secondaries irregularly scattered; on aboral side, also a regular series of primary tubercles beginning in the middle of the distal-most plate leading adapically to the outer edge of the plates. This oblique series is accompanied by a more irregular row of large secondary tubercles. Color: In the whole, light brown; oral primary spines banded in red and yellowish green; aborally, the red bands are brownish. Distribution: Japanese seas from Sagami Bay to Kagoshima Bay, 50–400 m deep. Hapalosoma pellucidum A. Agassiz, 1879 (Fig. 4.82 E, F) Test: Diameter may reach up to 100 mm. Ambulacra: One demi-plate is in contact with the outer suture not only on the oral side but often also on the aboral side. Interambulacrum: On oral side, rows of primary tubercles decrease in size toward the peristome; on aboral side, oblique series of primary tubercles occurs only distally; large secondary tubercles are absent. Color: In life, the specimens are grayish to almost transparent, those preserved in alcohol being more whitish.

4.2.1 Order Echinothurioida Claus, 1880 



A

C

 151

B

D

E

F

Fig. 4.82: (A) Calveriosoma gracile. (A) Aboral side with spines, diameter 122 mm; Kumano-nada, Pacific, Japan (coll. H. van Noordenburg). (B) Calveriosoma hystrix. Aboral side with some spines, diameter 108 mm; west coast of Ireland. ZMH. (C, D) Hapalosoma gemmiferum. (C) Aboral side with spines, test diameter 51 mm; Kumano-nada, Japan (coll. H. van Noordenburg). (D) Dactylous pedicellaria: the gland is well developed, the valves reduced. (E, F) Hapalosoma pellucidum. (E) Aboral side, test buffered; diameter 53 mm; Kei Islands, Indonesia. ZMUC. The madreporite is elevated. The membranous interstices are broad. The oblique series of primary tubercles occurs only distally and there are no larger secondaries. (F) Dactylous pedicellaria with reduced valves. Scale: (D, F) 1 mm (Mortensen 1935).

Cleaned tests are rather grayish olive with white plate sutures. The larger spines are banded in carmine, which does not fade out in alcohol. Distribution: Widespread in the Malayan Archipelago; recorded bathymetric range 180 to 270 m. Hapalosoma pulchrum Rowe, 1989 This species differs from its congeners by the total lack of primary tubercles on the aboral side. Test: Diameter of the sole specimen 67 mm. Pedicellariae: Small tridentate ones with a bluntly rounded tip.

Color: In the whole pale green, oral primary spines with narrow bands in purplish. Occurrence: Dredged off Norfolk Island, Tasman Sea. Depth range between 130 and 300 m. Genus Hygrosoma Mortensen, 1903 This genus is distinguished from the other genera by the position of the demi-plates on the oral side: both plates reach the outer edge of the area, the pore pairs being arranged in a single series. There are no membranous interstices between the plates. Test: Low, hemispherical, rounded pentagonal; large forms.

152 

 4.2 Subclass Euechinoidea Bronn, 1860

Apical system: Very variable in the membranous prolongation. Ambulacra: Distinctly narrower than interambulacra; on the oral side, both demi-plates reach the outer suture; on the aboral side, they are excluded from the edge, positioned in the middle of the plates. Interambulacra: Sutures narrow and without distinct membranous gaps; primary tubercles on oral side larger and much more numerous than those on aboral side and with wide and deep areoles. Peristomial plates: Buccal sacs well developed, deep and wide notches. Spines: Distal primaries on oral side with a conspicuous conical hoof; aboral spines with poison gland. The genus consists of three species, which differ mainly in the shape of their pedicellariae: Hygrosoma hoplacantha Thomson, 1877. Indo-Pacific. Hygrosoma luculentum A. Agassiz, 1879. Indo-Pacific. Hygrosoma petersii A. Agassiz, 1880. Northern Atlantic.

Hygrosoma hoplacantha Thomson, 1877 (Fig. 4.83 A–C) Test: Maximum diameter about 280 mm. Apical system: Small, enlarged madreporite. Ambulacra: Aborally three vertical series of pore pairs. Interambulacra: On aboral side, a few, irregularly distributed primary tubercles; on oral side, larger and more numerous, associated to wide, deep areoles. Spines: Near the apical system, distally invested in a thick skin sheath. Distribution: The species occurs from Japan through the Malayan Archipelago and northwest Australia to East Africa. Bathymetric range 360 to 2,068 m. Hygrosoma luculentum A. Agassiz, 1879 (Fig. 4.76 C4, 4.83 D) Test: Maximum diameter of 180 mm. Spines: Aborally three vertical series of pore pairs. Distal part of oral side with short series of large tubercles, adorally with scattered, small tubercles, primaries inconspicuous. Adapical spines with thick skin.

A

B

C

D

E

F

Fig. 4.83: (A–C) Hygrosoma hoplacantha. (A) Aboral side, diameter 132 mm; Pemba Strait, East Africa. ZMH. (B) Oral side: the typical large tubercles occur mainly on the distal part of the test. (C) Plate pattern of half an ambulacrum: the pore pairs of the primary plates form a third vertical series. Scale: 4 mm (Mortensen 1935). (D) Hygrosoma luculentum. Oral side with remaining spines, test buffered, diameter 145 mm; Mindanao, Philippines. ZMUC. The distal plates carry large primary tubercles, adorally there are only a few irregularly scattered small tubercles. (E, F) Hygrosoma petersii. (E) Aboral side, test buffered, diameter of test 148 mm; Bermuda Rise, North Atlantic. ZMUC. (F) Oral side: the primary tubercles on the oral side are much larger than those on the aboral side. They are surrounded by large and deep areoles.

4.2.1 Order Echinothurioida Claus, 1880 



Distribution: This species occurs throughout the Malayan Archipelago. Bathymetric range about 400 to 2,000 m. Hygrosoma petersii A. Agassiz, 1880 (Fig. 4.83 E, F) Test: The diameter may reach 180 mm. Ambulacra: Pore pairs forming only two series, the one of the primary plate positioned above that in the outer demiplate; demi-plates on oral side being in contact with outer suture. Interambulacra: Series of large tubercles on the distal oral side well developed; adorally much smaller and scattered. Spines: Adapical ones without skin bag. Distribution: This species is widely spread through­ out the North Atlantic from off southwest Ireland to the Azores and Senegal and from off New Jersey, USA, to the West Indies. It is also found off the Cape Peninsula, South Africa. Bathymetric range about 200 to 3,700 m. Genus Sperosoma Koehler, 1897 This genus was subject of discussions regarding the arrangement of the aboral primary plates: Mortensen (1935) interpreted them as 2 plates, one of them without a pore pair. Mooi et al. (2004) made careful reobservations

A

adapical demiplate primary perforated

C plate

 153

and could show that the supposed separation of the plate is an artifact of test breakage during collection and preservation. The test of Sperosoma is very fragile, and it is likely that the fracture along the line of podia is predisposed (Fig. 4.84 A). Literature: Mironov 2006; Mortensen 1935; Mooi et  al. 2004. Test: Low, circumference round; thin and fragile. Apical system: Membranous prolongation of genital plates variable, often inconspicuous. Ambulacra: On oral side, distinctly broader than interambulacra, often with convex outline; adorally of about the same width; adapical demi-plates large, in broad contact with outer suture; adoral demi-plates variable, mostly small, sometimes they may reach the inner suture; pore pairs forming an irregular band on the middle of the plates; primary tubercles on aboral side more or less in regular series, on underside becoming obscured adorally among the scattered secondary tubercles. Interambulacra: No membranous interstices; oral primary tubercles of about same size as on aboral side, forming more or less regular series along the outer edge and along the median suture, converging distally; inner part of oral side more or less densely set with scattered secondary tubercles.

A III

"nonperforated"

adoral demiplate

A IV

B

adapical demiplate perforated primary plate

adoral demiplate

Fig. 4.84: (A, B) Sperosoma. Diagrams of aboral ambulacral plates: (A) Mortensen’s interpretation: the primary plate is divided into 2 plates, one is perforated by a pore pair, one is not perforated. (B) Reinterpretation of Mooi et al.: the primary plate is not divided according the one-podium-per-plate rule. Scale: 30 mm (modified after Mooi et al. 2004). (C) Sperosoma grimaldii. Close-up of aboral side, diameter of test 95 mm; Azores. ZMUC. In ambulacrum III, the right column shows a distinct crack, where the plates are broken along the line of podia. In the left column of A III – and especially in A IV – several primary plates are preserved intact.

154 

 4.2 Subclass Euechinoidea Bronn, 1860

Spines: Aboral spines distally surrounded by a poison gland; oral spines with hoof. The genus contains ten species, all of which live in the deep sea. Sperosoma antillense Mortensen, 1934. West Indies. Sperosoma armatum Koehler, 1927. Arabian Gulf. Sperosoma biseriatum Döderlein, 1901. South Africa. Sperosoma crassispinum Mortensen, 1934. Indo-West Pacific. Sperosoma durum Döderlein, 1905. Indian Ocean. Sperosoma giganteum A. Agassiz & H. L. Clark, 1907. Japan. Sperosoma grimaldii Koehler, 1897. East Atlantic. Sperosoma nudum Shigei, 1977. Japan. Sperosoma obscurum A. Agassiz & H. L. Clark, 1907. Hawaii. Sperosoma quincunciale de Meijere, 1904. Indo-Pacific. Sperosoma tristichum Mortensen, 1934. Borneo. Sperosoma antillense Mortensen, 1934 Closely related to S. grimaldii, differs in the secondary and miliary tubercles being very scarce, particularly on the aboral side; only 1 pore pair of an aboral compound plate well developed. West Indies, about 700 m. Sperosoma armatum Koehler, 1927 Large tridentate pedicellariae with broad, almost square valves. Arabian Gulf, 1,800 m. Sperosoma biseriatum Döderlein, 1901 (Fig. 4.85 A) Apical system: Madreporite strongly enlarged and inflated, subdivided into 2 to 4 parts. Ambulacra: Primary plate does not usually extend over the whole area; aboral primary tubercles along the median line as large as in interambulacra. Interambulacra: Aborally up to four primary tubercles per plate in irregular vertical rows; on oral side, larger tubercles, decreasing in size toward the peristome. Distribution: Off South Africa, deep sea. Sperosoma crassispinum Mortensen, 1934 (Fig. 4.86 A) Diameter of sole specimen 145 mm. Aboral primary tubercles in ambulacra and interambulacra rather few and irregularly scattered. Occurrence: Moluccan Strait, 1,633 m. Sperosoma durum Döderlein, 1905 Diameter of sole specimen 112 mm. Test: Aboral side strongly calcified, so keeping its natural, lowly domed shape. Ambulacra: Aboral plates 3 times as numerous as those on the oral side. Pedicellariae: Ophicephalous ones present. Color: Deep purple red.

Occurrence: Indian Ocean, off Mogadischu, Somalia, at a depth 1,644 m. Sperosoma giganteum A. Agassiz & H. L. Clark, 1907 Diameter of the sole specimen 320 mm, with this size, the largest known Recent echinoid. Ambulacra: On aboral and oral side conspicuously broader than interambulacra. Occurrence: Shizuoka, Honshu, Japan. Depth 1,211 m. Sperosoma grimaldii Koehler, 1897 (Fig. 4.84 C, 4.85 B–E) Test: Lowly arched, oral side more flattened, circumference round. Apical system: Very variable in the prolongation of the membranous gaps perforated by genital pores. Ambulacra: On oral side, broader than interambulacra with convex outlines, aborally of about the same width; on aboral side, the adapical demi-plate is in broad contact with the outer suture; the adoral demi-plates become smaller toward the ambitus; pore pairs may be reduced in primary plate and adapical demi-plate; on oral side, large primary tubercles only near the margin, adorally scattered small secondary tubercles. Interambulacra: On oral side, two series of primary tubercles distally bending according to the convex outline of the ambulacra, decreasing in size adorally and indistinct among small scattered secondary tubercles; on aboral side, primary tubercles in two fairly regular series. Color: The skin is dark purplish brown with white spines, cleaned tests are white. Distribution: The species is found in the eastern Atlantic from South of Iceland to the Gulf of Guinea including the Azores and the Cape Verde Islands. Bathymetric range 235 to 2,910 m. Sperosoma nudum Shigei, 1977 No larger primary tubercles on aboral side. Distribution: Off Central Japan, North Pacific. Depth range 1,410 to 2,018 m. Sperosoma obscurum A. Agassiz & H. L. Clark, 1907 (Fig. 4.86 D) Diameter up to 169  mm; hoofs very short, but flaring; tridentate pedicellariae with long, slender valves. Distribution: Endemic to the Hawaiian Islands, 300–1,245 m. Sperosoma quincunciale de Meijere, 1904 This species is very typical in having a white line around the apical plates encircling the genital plates but excluding the ocular plates. Valves of tridentate pedicellariae triangular in outline. Distribution: Indo-Pacific from Japan to Timor, recorded from a depth of 785 to 910 m.

4.2.1 Order Echinothurioida Claus, 1880 



B

A

C

 155

D

E

Fig. 4.85: Sperosoma biseriatum. (A) Aboral side, test buffered, diameter 120 mm; off Natal, South Africa. ZMUC. (B–E) Sperosoma grimaldii. (B) Oral side of test, diameter 95 mm; Azores. ZMUC. The series of primary tubercles in the interambulacra are distinctly arched, corresponding to the convex outline of the ambulacra (close-up of aboral side Fig. 4.84 C). (C) Tridentate pedicellariae. (D) Spines with hoofs. Scale: 10 mm. (E) Aboral plates of half an aboral ambulacrum: only in one demi-plate per triplet, the pore pairs are well developed, the two others are reduced. Scale: 3 mm (Mortensen 1935).

Sperosoma tristichum Mortensen, 1934 (Fig. 4.86 B, C) Diameter of sole specimen 95  mm. Pore pairs on aboral side in distinct arcs of three. Occurrence: Off Borneo, 660 m. Genus Tromikosoma Mortensen, 1903 The genus is very closely related to Sperosoma. It differs from all other echinothuriids by the lack of buccal notches and sacs; occasionally, they may be developed rudimentary. Test: Large, low, round, and exceedingly delicate, which leads mostly to an extraordinary breaking up of the plates into small fragments. There are no membranous interstices between the plates. Apical system: In large specimens, the membranous gaps with gonopores extend far into the interambulacra.

Ambulacra: Almost as broad or broader than interambulacra at ambitus; adapical demi-plate large, broadly contacting the outer suture, adoral demi-plate much smaller and usually occluded from both sides; pore pairs in the middle of the plates, rudimentary on some elements on the aboral side. Interambulacra: Outer and inner series of primary tubercles more or less developed, on oral side much larger than on aboral side. Peristome: Only 5–6 plates. Spines: Oral spines with conical hoof, aboral spines distally with venomous gland. The genus consists of six species, which are difficult to distinguish. Tromikosoma australe Koehler, 1922. New Zealand. Tromikosoma hispidum A. Agassiz, 1898. East Pacific.

156 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

B

CB

D

Fig. 4.86: (A) Sperosoma crassispinum. Aboral plates of half an ambulacrum. Scale: 6 mm. The test seems to be rather solid because the primary plates are undivided as Mortensen (1935) has drawn them. B, C Sperosoma tristichum. (B) Aboral plates of half an ambulacrum near the apical disc. (C) Plate pattern on aboral distal area. About midway to the ambitus the pattern changes, the broad adapical demi-plate becomes smaller; distally it is as small as the adoral demi-plate. (D) Sperosoma obscurum Aboral plates of half an ambulacrum. The pores form a broad band. Scales: (A, D) 6 mm; (B, C) 4 mm (Mortensen 1935, modified according to the interpretation of Mooi et al. 2004).

Tromikosoma koehleri Mortensen, 1903. Davis Strait, northwest Atlantic. Tromikosoma panamense A. Agassiz, 1898. East Pacific. Tromikosoma tenue A. Agassiz, 1879. Pacific from the Aleutian Islands to the Moluccan Sea. Tromikosoma uranus Thomson, 1877. East Atlantic. Tromikosoma australe Koehler, 1922 Off north New Zealand. Depth 3,240 m; not well known. Tromikosoma hispidum A. Agassiz, 1898 (Fig. 4.87 A, B) Diameter may reach 203 mm. Apical system: Large specimens have very long membranous gaps with gonopores. Ambulacra: Only slightly broader than interambulacra. Distribution: This species is known from the Gulf of California to the Galapagos Islands. Recorded bathymetric range 1,790 to 2,560 m. Tromikosoma koehleri Mortensen, 1903 Diameter of sole specimen 180 mm, badly preserved. Apical system: Madreporite indistinct within the ring of genital and ocular plates.

Ambulacra distinctly broader than interambulacra at ambitus. Color: Rather light. Occurrence: Davis Strait, northwest Atlantic, 2,580 m. Tromikosoma panamense A. Agassiz, 1898 Ambulacra: Conspicuously broader than interam­ bulacra. Small tubercles much more numerous than in T. hispidum. Small tridentate pedicellariae with very broad, leaf-shaped valves. Distribution: East Pacific from Malpelo Island over Panama to Galapagos Island. Depth 2,054 to 3,333 m. Tromikosoma tenue A. Agassiz, 1879 Diameter of test up to 170 mm. Ambulacra: On aboral side, only one of the pore pairs per compound plate is well developed. Peristome: Occasionally rudimentary buccal sacs may occur. Large tridentate pedicellariae may reach a length of 6.5 mm, the largest known in echinoids. Color: Dark violet purple on the oral side, light yellowish aborally.

4.2.1 Order Echinothurioida Claus, 1880 



B

A

C

 157

D

E

Fig. 4.87: (A, B) Tromikosoma hispidum. (A) Oral side of relatively young specimen, test buffered; diameter 74 mm; Gulf of Panama, East Pacific. ZMUC. This specimen is well preserved. There are no traces of buccal sacs at the edge of the peristome. (B) Aboral side: the specimen still has a rather compact apical system. (C–E) Tromikosoma uranus. (C) Aboral side, diameter of test about 125 mm, off Cap Blanc, Mauretania (photos by B. Ruthensteiner, ZSM). (D) Oral side. (E) Ambulacral plates on oral side: the large tubercles of the primary plates form an oblique row. Scale: 20 mm (Mortensen 1927, modified according to Mooi et al. 2004).

Distribution: North Pacific from the Aleutian Islands over Japan to the Moluccan Sea, 1,530 to 3,375 m. Tromikosoma uranus Thomson, 1877 (Fig. 4.87 C–E) Main characteristics of the genus. Test: Low and hemispherically elevated. Apical system: Madreporite large and conspicuous. Ambulacra on oral side: The distal five to six primary plates carry each a large primary tubercle, forming oblique, slightly curved rows and approaching each other toward the ambitus. Color: Much darker than T. koehleri. Distribution: Eastern Atlantic from Portugal to West Africa at depths of 838 to 2,745 m.

Infraclass: Acroechinoidea This infraclass comprises about three quarters of all living sea urchins. One can differentiate two major groups: Regulars, with pentameral symmetry containing eight orders. Irregularia, with bilateral symmetry containing five or six orders (Volume II). All regular acroechinoids, which means above the echinothurioids within the phylogenetic system, have the following features in common: The ambulacral plating on the peristomial membrane is reduced to 5 pairs of large buccal plates. A single ambulacral plate consists of

158 

 4.2 Subclass Euechinoidea Bronn, 1860

A

pore zone

interporiferous zone

B

pore zone

horizontal suture

median suture horizontal suture

compound plate

pore-pairs primary tubercle

secondary tubercle median suture

secondary tubercle

primary tubercle

miliary tubercle

miliary tubercle

C

A III

buccal notches IA 3

IA 2

C A IV

A II

buccal plates

IA 1

mouth with teeth

IA 4

AV

AI

peristomial membrane

IA 5

Fig. 4.88: Characteristics of regular acroechinoid. (A) Ambulacral plates: each compound plate consists of several elements, according to the species from three up to 19, each being perforated by a pair of pores and fused by the overgrowth of a primary tubercle, surrounded by smaller secondaries and even smaller miliaries. (B) Interambulacral plate: there is one primary tubercle, mostly the largest, and smaller secondaries and miliaries. (C) The peristome with the central mouth opening on the oral side is closed by a membrane, which may be naked or covered by irregularly scattered, small plates. Five pairs of buccal plates, each with a single pore pair and tube foot, are arranged around the mouth. In the interambulacra, the edge of the test is indented by more or less deep buccal slits, where the buccal sacs protrude.

several elements (compound plate), each perforated by a pair of pores and fused together by the overgrowth of a primary tubercle (Fig. 4.88 A–C). Test: Usually round and more or less inflated. Interambulacra: One plate carrying one primary tubercle, heterogeneous secondary and miliary tubercles.

Peristome: Teeth grooved; auricles in ambulacral position (in cidarids these processes are interambulacral in position). “Diadematacea” The most primitive members of the Acroechinoidea, grouped together by the informal name “Diadematacea”, consist of four orders: Order Aspidodiadematoida. One family with two genera.

4.2.2 Order Aspidodiadematoida Kroh & Smith, 2010 



A

B

C

 159

D

Fig. 4.89: (A) Order Aspidodiadematoida: the apical plates are embedded in a membrane, genital and ocular plates being of same size. (Plesiodiadema indicum, scale 10 mm). (B, C) Order Diadematoida. (B) Hemicyclic apical system: only the ocular plates I, IV, and V are in contact with the periproctal edge being insert; II and III are exsert (Centrostephanus rodgersii, scale 10 mm). (C) Monocyclic apical system: the ocular plates are broadly in contact with the periproctal plates, they are all insert (Chaetodiadema pallidum, scale 10 mm). (D) Order Pedinoida: dicyclic apical system: the ocular plates do not touch the periproctal edge; they are all exsert (Caenopedina mirabilis, scale 5 mm). (The genital and ocular plates are marked by darker lines.)

Order Diadematoida. One family with eight genera. Order Micropygoida. One family with a single genus, being unique in having umbrella-shaped pedicellariae. Order Pedinoida. One family with two genera. Their jaw apparatus is of “aulodont” type with grooved teeth (see Fig. 2.10 A), closely related to that of cidarids, and their ambulacral plates are principally compounded of three elements. Recent phylogenetic analyses (Kroh & Smith 2010) showed that each order forms a separate lineage with a long independent history. Early diademataceans are the ancestors of the Irregularia, which evolved in the Lower Jurassic. After separation, both groups, the pentameral and the bilateral acroechinoids, underwent a rapid radiation specializing for differing habitats: the regulars remained restricted to solid grounds and an epibenthonic life; the irregulars burrowed into soft substrates, presumably to avoid predation. Predominantly, they live today infaunally.

4.2.2 Order Aspidodiadematoida Kroh & Smith, 2010 The order consists of a single family.

4.2.2.1 Family Aspidodiadematidae Duncan, 1889 The species of this family are remarkably consistent in their characteristics. They are of small to moderate size with subglobular tests. All tubercles are perforated and strongly crenulated. The genital and ocular plates

are embedded in a membrane and not attached to the corona. The primary spines are very long, about 3–4 times the diameter of test, although very rarely preserved, being extremely brittle, curving downward, and ending in a hoof-like widening. This “hoof” is not homologous with the hoof of the echinothurioids, but merely a continuation of the spine. There are two genera that distinctly differ in the arrangement of their ambulacral plates and the size of the ambulacral tubercles. (Fig. 4.90 A, B) Plesiodiadema Pomel, 1883. Primitive feature: simple ambulacral plates; ambulacral tubercles much smaller than interambulacral ones. Aspidodiadema A. Agassiz, 1879. More derived with compound plates consisting of three elements; ambulacral tubercles at the ambitus of approximately the same size as the interambulacral ones, forming an alternating series. Genus Plesiodiadema Pomel, 1883 Test: Globular, diameter may reach 37 mm. Apical system: Large, monocyclic, forming a ring of genital and ocular plates that are usually of same size and shape; peristome covered in more or less numerous plates around anal opening, remaining membrane naked; all plates densely tuberculated. Ambulacra: Very narrow, plates simple with 1 pore pair per plate, primary tubercles only on every third plate, crenulated, tubercles, and consequently, the spines are much smaller than in interambulacra. Interambulacra: Set with two series of large, strongly crenulate primary tubercles; the areoles being confluent; secondaries small and uniform.

160 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

E

Fig. 4.90: (A, B) Ambulacral plate pattern of aspidodiadematids. (A) Plesiodiadema molle with simple plates. Only every third plate is set with a primary tubercle. (B) Aspidodiadema nicobaricum with compound plates. The primary tubercles are positioned on the largest element and cover also parts of the adjoining upper and lower elements (at ambitus). (C) Plesiodiadema indicum. Side view, diameter 31 mm; Gilolo Island, Philippines. ZMUC. The ambulacra are narrow, the plates are set by small, uniform tubercles. The primary tubercles are not very distinct. (D) Aspidodiadema meijerei. Side view of test, diameter 24 mm; Zamboanga, Philippines. ZMUC ECH 15. In the ambulacra the primary tubercles are almost as large as those in the interambulacra, disappearing abruptly above the ambitus. (E) Plesiodiadema indicum. Sketch in Mortensen 1940, diameter of test about 30 mm; Kei Islands, Indonesia. The very long primary spines are curved downward ending distally in a more or less flattened widening. Scales: (A) 1 mm; (B) 4 mm (Mortensen 1940).

Peristome: Distinct buccal notches; buccal plates large with a single large tube foot, clinging closely together covering most of the membrane. Spines: Primary spines very long, curved downward and extremely fragile. Mortensen recorded seven species. Plesiodiadema amphigymnum (de Meijere, 1902). Gulf of Bone, Celebes, Indonesia. Plesiodiadema antillarum (A. Agassiz, 1880). Caribbean to Brazil and St. Helena. Plesiodiadema globulosum (A. Agassiz, 1898). West coast of South America. Plesiodiadema horridum (A. Agassiz, 1898). West coast of South America.

Plesiodiadema indicum (Döderlein, 1900). Malayan Archipelago. Plesiodiadema microtuberculatum (A. Agassiz, 1879). Tristan da Cunha. Plesiodiadema molle (Döderlein, 1901). Central Indian Ocean. Plesiodiadema amphigymnum de Meijere, 1902 Typical for this species is the single circle of small plates closely surrounding the periproct. The buccal plates are not set with spines. The four specimens recorded by de Meijere and Mortensen (1940) are not more than 10 mm in diameter. All of them were found in and at the mouth of the Gulf of Bone, Celebes, Indonesia. Bathymetric range 1,158 to 1,450 m.

4.2.2 Order Aspidodiadematoida Kroh & Smith, 2010 



A

 161

B

C

D

E

F

G

Fig. 4.91: (A–C) Plesiodiadema antillarum. (A) Aboral side of test with some remaining spines, diameter 14 mm; Sao Tomé, West Africa. ZMUC. Only the center of the periproctal membrane is set by a couple of small plates, which are densely covered by small spines. (B) Side view of test. (C) Apical system: each ocular plate carries a larger tubercle in addition to the usual small uniform tubercles. (D, E) Plesiodiadema globulosum. (D) Apical system: the periproctal membrane is covered in small plates. Diameter of test 25 mm. (E) Ambulacral plates: the interambulacral areoles do not join the ambulacral edge. (F, G) Plesiodiadema horridum. (F) Apical system. Test diameter 20 mm. In contrast to P. globulosum, this species has smaller and more numerous periproctal plates. (G) Ambulacral plates: the primary tubercles are smaller than in P. globulosum and the areoles of the interambulacral primary tubercles reach the sutures. Scales: (C) 3 mm; (E, G) 2 mm (Mortensen 1940); (D, F) no scale (A. Agassiz 1904).

Plesiodiadema antillarum A. Agassiz, 1880 (Fig. 4.91 A–C) Main characteristics of the genus. Test: Diameter may reach 26 mm. This species differs from the others by having only a few small periproctal plates lying in the center of the

membrane. The coronal plates are less numerous than in other species. Color: Test and spines dark purplish red. Distribution: This species is spread over the warmer parts of the Atlantic from the Caribbean to Brazil and from

162 

 4.2 Subclass Euechinoidea Bronn, 1860

the Strait of Gibraltar over the Canaries to St. Helena and probably Tristan da Cunha (P. microtuberculatum). Bathymetric range about 750 to 3,100 m. Remarks: Mortensen (1940) stated that Plesiodiadema antillarum and P. microtuberculatum are very closely related, and the differences between them not clear. It is likely that they form a single Atlantic species. Plesiodiadema globulosum A. Agassiz, 1898 (Fig. 4.91 D, E) According to Mortensen, the areoles of P. globulosum do not touch the ambulacral edge as in P. horridum, leaving space for numerous small tubercles. The periproctal membrane is covered in several plates, which are not restricted to a ring surrounding the periproct being largest near the anal opening. Peristome: Buccal plates set with tubercles resp. spines. Color: In live specimens, test and spines are dark purple. Distribution: Known from the deep waters off the west coast of South America from the Malpelo Island to Valparaiso, Chile, at depths of 3,830–about 3,900 m. Plesiodiadema horridum A. Agassiz, 1898 (Fig. 4.91 F, G) This species is well distinguished from P. globulosum living in the same region: Apical system: Periproctal plates smaller and more numerous. Interambulacra: The areoles reach closer to the ambulacral edge, leaving no space for small tubercles. Peristome: Buccal plates naked. Color: Tests of live specimens are claret red, the spines pinkish. Distribution: Off Panama, Cocos and Galapagos Islands. Depth 1,625 to 3,190 m. Plesiodiadema indicum Döderlein, 1900 (Fig. 4.89 A, 4.90 C, E, 4.92 A–E) The globular test may reach a diameter of 37 mm. Apical system: Monocyclic, periproctal plates scattered over the whole membrane. Ambulacra: Primary tubercles indistinct, barely larger than secondaries, at every third plate horizontal suture depressed in a pit; pore pairs relatively large. Interambulacra: 13–14 coronal plates per column; primary tubercles with extremely strong crenulation; the boss is vertically elongated with an oval perforation. Spines: Primary spines very long, very slender, very brittle, and distally ending in a widening, curved toward the bottom. Color in life: The test is generally white, the aboral side reddish. The primary spines are pale red.

Distribution: The species is found throughout the entire Malayan Archipelago, the Philippines, and in the East China Sea. The bathymetric range is 300 to 520 m. Plesiodiadema molle Döderlein, 1901 (Fig. 4.90 A, 4.92 F) Main characteristics of the genus. Apical system: Ocular plates with one larger tubercle, genital papillae present. Interambulacra: Up to 8 coronal plates only (in contrast to P. indicum). Peristome: Buccal plates set with spines (in contrast to P. amphigymnum). Distribution: Indian Ocean. Bathymetric range 2,253 to 3,385 m. Genus Aspidodiadema A. Agassiz, 1879 Test: High, diameter may reach more than 30 mm. Apical system: Monocyclic, some larger plates cover the periproctal membrane around the anal opening. Ambulacra: Compound plates with three elements, set with one large, mostly elongate-oval tubercle, forming an alternating series, disappearing abruptly at or above the ambitus; pore pairs in steep arcs of three or nearly straight lines. Interambulacra: Two regular series of large, mostly elongate-oval tubercles with more or less confluent areoles. Peristome: Rounded buccal notches; large buccal plates each with a large tube foot. Spines: Primaries very long and slender, about 4 times the test diameter, curved downward, but extremely fragile and rarely preserved; shaft verticillate; secondary spines fine and short. The genus Aspidodiadema consists of ten species: Aspidodiadema africanum Mortensen, 1939; off East London, South Africa. Aspidodiadema arcitum Mortensen, 1939; Hawaii. Aspidodiadema hawaiiense Mortensen, 1939; Hawaii. Aspidodiadema intermedium Shigei, 1977.  East China Sea. Aspidodiadema jacobyi A. Agassiz, 1880; West Indies. Aspidodiadema meijerei Döderlein, 1906; Malayan Archipelago. Aspidodiadema montanum Mironov, 1981. On sea-mounts in the Central Pacific. Aspidodiadema nicobaricum Döderlein, 1901; Nicobar Islands, Indian Ocean. Aspidodiadema sinuatum Mironov, 1981. On sea-mounts in the Central Pacific. Aspidodiadema tonsum A. Agassiz, 1879. West Pacific. Development: Young & George (2000) succeeded in culturing embryos of Aspidodiadema jacobyi from the deep

4.2.2 Order Aspidodiadematoida Kroh & Smith, 2010 



B

A

C

 163

D

E

F

Fig. 4.92: (A–E) Plesiodiadema indicum. (A) Aboral side of test, diameter 31 mm; Gilolo Island, Philippines. ZMUC. (B) Oral side with large buccal plates (side view see Fig. 4.90 C). (C) Apical area with spines, diameter of test 25 mm; off northeast Taiwan, East China Sea. Each plate on the periproctal membrane is set with a bunch of very fine spines. (D) Distal part of primary spine with widened end. (E) Base of an aboral primary spine. Scale: 2 mm (Mortensen 1940). (F) Plesiodiadema molle. Aboral side with remaining spines, diameter 18 mm; Indian Ocean between the Maldives and Chagos Island (photo by B. Ruthensteiner, ZS Munich).

sea near the Bahamas. They could observe the development from the egg to a late larval state, but none of the specimens metamorphosed. Over a period of 5 months, the embryos grew from a small egg (98 μm) via the non-feeding larvae to very large (3071 μm) plankton feeding (planktotrophic) echinopluteus larvae. In its natural environment, these larvae could be dispersed over a distance of about 650 km according to roughly estimated water currents. Two results were remarkable: (i) the small eggs contain maternal yolk resources, which enables the

embryos to survive up to 2  months without feeding; (ii) the larvae develop 10–12 arms and a conspicuous posterior process. In contrast, the Diadematidae (with Lissodiadema) and the Micropygoida have only two arms and no posterior process. With the numerous arms, the aspidodiadematid echinopluteus shows remarkable similarities to that of the irregular spatangoids and clypeasteroids. Thus, it is likely that the ancestors of the aspidodiadematids may be near the stem group, which separates the regular and the irregular echinoids, while the 2-arm larva evolved only once.

164 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

E

Fig. 4.93: (A) Aspidodiadema africanum. Side view with remaining spines, diameter of test 15 mm; South Africa. ZMUC ECH 86. (B) Aspidodiadema arcitum. Aboral side with some spines, diameter of test 22 mm; Horizon Guyot, Central Pacific. (C) Aspidodiadema hawaiiense. Side view of test, diameter 20 mm; Oahu, Hawaii, USA. ZMUC ECH 170. (D, E) Aspidodiadema meijerei. (D) Ambital ambulacral plates. (E) Part of apical system: the plates are uniformly tuberculated. Scale: 4 mm; Mortensen 1940.

Aspidodiadema africanum Mortensen, 1939 (Fig. 4.93 A) Test: Diameter may reach 16 mm. Apical system: Ocular plates broader than genitals, both carrying one large tubercle at the inner edge; small tubercles not as numerous as in A. tonsum; periproctal plates small. Ambulacra: Pore pairs arranged in an almost straight line. Interambulacra: Primary tubercles oval, areoles very large, secondary tubercles small and scarce.

Peristome: Buccal plates with 3–4 slightly club-shaped spines. Color: The test is a light purple, the primary spines seem to be almost white. Distribution: Known only from the east coast of South Africa at depths of 720 to 810 m. Aspidodiadema arcitum Mortensen, 1939 (Fig. 4.93 B) Test: Diameter may reach 26 mm. Apical system: Genital and ocular plates rather low, every ocular plate with a distinct large tubercle and



scattered smaller ones; 6–10 small periproctal plates forming a circle. Ambulacra: Pore pairs at ambitus arranged in distinct arcs of three. Interambulacra: Primary tubercles oval; areoles large, leaving only narrow spaces for a series of secondary tubercles along the median line and on the outer edge of the plates. Color: Purplish with white tubercles. Distribution: The species is restricted to the region around the Hawaiian Islands. Bathymetric range 300 to 1,450 m. Aspidodiadema hawaiiense Mortensen, 1939 (Fig. 4.93 C) Main characteristics of the genus. This species differ from the other Hawaiian species by its color. In A. hawaiiense, the spines are brightly green; in A. arcitum, they are light purple to white. The denuded test of A. hawaiiense is white with a tinge of purple; in A. arcitum, it is a distinctly pale purple. Distribution: The species is restricted to the Hawaiian Islands at depths of 345 to 680 m. Aspidodiadema intermedium Shigei, 1977 With a maximum test diameter of 38 mm, it is the largest known Aspidodiadema. Ambulacra: Pore pairs in oblique arcs of three. Tubercles round. Color: Test whitish, spines purplish to greenish. Distribution: East China Sea at a depth of 380 m. Aspidodiadema jacobyi A. Agassiz, 1880 Color: Test and tubercles are greenish, also the spines.

Fig. 4.94: Aspidodiadema meijerei. Aboral side, partly with spines, diameter of test 19 mm; Banda Sea, Indonesia. ZMUC. The periproctal membrane is transparent.

4.2.2 Order Aspidodiadematoida Kroh & Smith, 2010 

 165

This species is the only aspidodiadematid living in the Atlantic. It is known from the West Indian Sea, from off the Bahamas to off Yucatan. Recorded bathymetric range 170 to 610 m. Aspidodiadema meijerei Döderlein, 1906 (Fig. 4.90 D, 4.93 D, E, 4.94.) Test: Almost globular, upper side slightly flattened; diameter may reach 23 mm. Apical plates: Rather high, densely covered by uniform small tubercles, no large tubercles. Ambulacra: Pore pairs in distinctly oblique arcs of three. Interambulacrum: Areoles relatively small, not confluent, leaving broad spaces densely covered by uniform secondary tubercles, which are also distributed at the ambulacral edge and along the midline. Primary spines: Very long and curved  – a specimen of 23 mm in diameter has kept a spine of about 90 mm. Color: The denuded test is light green; the uppermost tubercles being more intensely green. Both primary and secondary spines are also green. Distribution: The species seems to occur throughout the entire Malayan Archipelago. Depth range 204 to 385 m. Aspidodiadema montanum Mironov, 1981 Occurrence: On seamounts and knolls at the Necker Ridge and adjacent regions, northern Central Pacific. Depth range 1,270 to 1,950 m. Aspidodiadema nicobaricum Döderlein, 1906 (Fig. 4.90 B, 4.95 A–C) Test: Subglobular, upper side flattened; maximum diameter 36 mm. Apical system: All plates tuberculated, ocular plates with larger tubercles along the periproctal edge. Ambulacra: Pore pairs in steep series. Interambulacra: Areoles confluent, only narrow spaces with few secondary tubercles along the ambulacral edge and the median line. All primary tubercles round with a round perforation in the center, not elongated-oval as in the other species. Color: The well-cleaned test shows a light red brown; the primary tubercles are white on a pink boss, areoles may be also more or less pink; the primary spines are dark red purple, the secondary spines pale purple; the white periproctal membrane is very conspicuous. Distribution: This species was only found off the Nicobar Islands at a depth of about 300 m.

166 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

E

C

Fig. 4.95: (A–C) Aspidodiadema nicobaricum. (A) Aboral side of test partly with spines, diameter 33 mm; off Nicobar Islands. ZMH E 23. (B) Oblique view of test. (C) Ambital ambulacral plates. Scale: 4 mm (Mortensen 1940). (D, E) Aspidodiadema tonsum. (D) Aboral side of test, diameter 18 mm; Palawan Passage, Philippines. ZMUC. Each ocular plate is set with a large tubercle. (E) Side view: the pore pairs form nearly astraight line.

Aspidodiadema sinuosum Mironov, 1981 Occurrence: On seamounts and knolls at the Necker Ridge and adjacent regions, northern Central Pacific. Depth range 100 to 1,350 m. Aspidodiadema tonsum A. Agassiz, 1879 (Fig. 4.95 D, E) Test: Almost globular, upper side slightly flattened; maximum diameter 21 mm. Apical system: All plates densely tuberculated, one large tubercle at the inner edge of each ocular plate; periproctal plates more or less centrally positioned on the membrane.

Ambulacra: Pore pairs very steep, forming a rather straight line; primary tubercles smaller than those in the interambulacra. Interambulacra: Areoles of primary tubercles broadly confluent, median space of plates densely covered by small secondary tubercles, only a few of them along the outer edge. Primary spines: Long and curved, strongly verticillate. Color: Test and spines are purple; the tubercles white. Distribution: This species is found throughout the West Pacific from Japan to the Philippines and the Malayan region, to eastern Australia and the Kermadec Islands, New Zealand. Bathymetric range 180 to 1,135 m.



4.2.3 Order Diadematoida Duncan, 1889 A single family is included in this order. It is characterized by a monocyclic or hemicyclic apical system, the genital plates projecting distinctly into the interambulacra. The primary tubercles are perforate and crenulate, and the spines are verticillate or finely thorny (except in Lissodiadema, which has non-crenulate tubercles and smooth spines). The axial cavity is mostly hollow; only in Astropyga is it filled with sparse meshwork.

4.2.3.1 Family Diadematidae Gray, 1855 Eight genera belong to the family: Astropyga Gray, 1825. Three species. Centrostephanus Peters, 1855. Nine species. Chaetodiadema Mortensen, 1903. Six species. Diadema Gray, 1825. Six species. Echinothrix Peters, 1853. Two species. Eremopyga A. Agassiz & H. L. Clark, 1908. Two species. Goniodiadema Mortensen, 1939. Monospecific. Lissodiadema Mortensen, 1903. Two species. The members of the diadematids are characterized by the following features: Test: Round and more or less low, mostly large forms; some genera with inflated ambulacra. Apical system: Monocyclic or hemicyclic, the genital plates projecting distinctly into the interambulacra. Ambulacra: Much narrower than interambulacra; plates consisting of three elements each with a pore pair; primary tubercles perforate and crenulate. Interambulacra: Broad, primary tubercles perforate and crenulate. Peristome: More or less deep buccal notches. Spines: Verticillate or with fine thorns (except Lissodiadema); axial cavity usually hollow. Some genera, namely Diadema, Astropyga, and Chaetodiadema, have developed bright iridescent spots or lines along the naked zones of the aboral interambulacra or over the apical plates (Fig. 4.105 B). The white spots or lines are created by a lack of pigment in conjunction with only a thin epidermis, revealing the test beneath. Being very conspicuous in Diadema setosum and D. palmeri both day and night, they are only visible at night in the other species of Diadema. These white spots are positioned directly over the gonads and may relate to detecting moonlight levels as a stimulus for spawning. The arrangement of these “lights” is highly variable. The blue spots and lines are iridophores, which reflect light onto the chromatophores, which are located in the dark

4.2.3 Order Diadematoida Duncan, 1889 

 167

pigmented areas of the test. It is likely that blue light is reflected, as this penetrates water to greater depths than light at other colors. It thus provides the maximum sensitivity to shadows cast by possible predators (S. Coppard, personal communication). But their true function is still unclear, as in Astropyga, the largest iridescent spots are developed at the underside. Some diadematid species have developed a bubble-shaped anal tube at the periproct, where feces is stored during daylight and vented at night. Literature: Coppard & Campbell 2004, 2005a,b, 2006a,b; Coppard & van Noordenburg 2007. Genus Astropyga Gray, 1825 Test: Flexible with internally imbricating plates adapically; outline circular to rounded pentagonal; oral side flat, upper side lowly convex; large forms up to 200 mm. Apical system: Depressed; genital plates narrow and long, extending into the interambulacra, gonopores at the distal end; the periproctal membrane may be flat or raised like a cone. Ambulacra: Narrow, inflated on the aboral side like a wall with small, irregularly arranged primary tubercles; on oral side arcs of pore pairs steep, on aboral side low. Interambulacra: Two series of primary tubercles, between which are aborally naked areas, joining like an inverted V at the distinctly depressed median line below the genital plates, more or less bordered by spots in small, but distinct pits; oral side densely covered with equalsized tubercles. Spines: Not hollow but filled with sparse calcitic meshwork; nevertheless very fragile; shorter on oral side; all of them covered by very small thorns. Biology: The species of Astropyga are voracious predators in the littoral or sublittoral, moving swiftly across sandy and hard grounds. They consume bottom material including encrusting and free-living organisms like foraminifera, bryozoans, small molluscs, and crabs. The urchins often group together, at night more active than in daylight. Some small fish live as commensals between the spines of Astropyga radiata. When disturbed, the animals group their spines into 5 cone-shaped bundles. Three species are known with distinctly separated geographical distributions: Astropyga magnifica A. H. Clark, 1934. South Carolina, USA, to Suriname. Astropyga pulvinata (Lamarck, 1816). West coast of America. Astropyga radiata (Leske, 1778). Indo-Pacific.

168 

 4.2 Subclass Euechinoidea Bronn, 1860

B

A

E

C

D F

Fig. 4.96: (A–C) Astropyga pulvinata. (A) Aboral side, diameter with spines ca. 130 mm; Isla Uva, Pacific Panama. The spines are banded. (B) Close-up of aboral side, diameter of test 80 mm; Peru. ZMH. The dark V-shaped area contrasts sharply against the whitish median part of the interambulacrum. (C) Aboral side of denuded specimen, diameter of test 113 mm; Tortola, Panama, Pacific. ZMUC. (D–F) Astropyga radiata. (D) Aboral side with spines, diameter of test 118 mm; Negros, Philippines. The spines are relatively short, not more than 30–40 mm, here mostly broken. (E) Close-up of aboral side, diameter of test 50 mm; Negros, Philippines. The dark molds arranged along the interambulacra mark the bright blue iridescent spots (arrows). (F) Aboral side of test, diameter 121 mm; Cebu, Philippines.

Astropyga magnifica A. H. Clark, 1934 (Fig. 4.96 A–C) Characteristics of the genus. Test: Diameter may reach 200 mm. Color: The naked areas in the interambulacra are golden yellow, the ambulacra are brown bordered by single rows of iridescent blue spots. The anal tube is very conspicuously bluish white with a dark anus ringed by a brown band. The spines have narrow bands in red brown and yellowish white.

Distribution: The species is known from South Carolina, USA, the southeastern Gulf of Mexico and the Greater and Lesser Antilles to Colombia to Suriname. Bathymetric range 11 to 88 m. Astropyga pulvinata Lamarck, 1816 Main characteristics of the genus. Test: Diameter up to 200 mm.



Astropyga pulvinata differs from the two other species in the tuberculation in the aboral interambulacra: in A. radiate, the primary tubercles along the outer side are quite regular leading up to the apical system with a parallel row of secondaries disappearing halfway up; in A. pulvinata, the rows look more irregular and the secondaries reach the apical disc, not the primaries. Furthermore, in A. radiate, the median angle between the two naked areas is regularly tuberculated, whereas in A. pulvinata, it is also naked and marked by the light color. Color: The test is greenish, including the naked V-shaped areas, sharply contrasting with the whitish median part of the interambulacra. The spines are banded whitish and brown. The blue spots, bordering the outer side of the dark V-shaped zone, are very bright. The anal tube is whitish with a brownish, poorly defined ring. Mortensen reported a dark purplish variety, venusta. Distribution: This species lives along the west coast of America from the Gulf of California to Peru in depths of 5 to 30 m. Astropyga radiata Leske, 1778 (Fig. 4.96 D–F) Main characteristics of the genus. Test: Diameter may reach more than 200 mm. Ambulacra: On the upper side, the pore zones are a broad band of densely set, oblique rows of pore pairs; on the underside, they are distally a straight line, but widened toward the peristome, becoming distinct phyllodes (in contrast to Eremopyga). Color: The spines and the test are mostly reddish brown to purple; the naked zones are a darker red purple, with bright blue spots on each plate, sometimes more than one. The cleaned test is greenish white. In young specimens, the spines are banded in white and purplish brown. Distribution: This species is known throughout the entire Indo-Pacific region from Zanzibar and Durban in East Africa to Queensland, Australia, and the Hawaiian Islands from the littoral zone to a depth of 60 m. Genus Centrostephanus Peters, 1855 This genus is distinguished from the other diadematoid genera in having a single enlarged primary tubercle in the interambulacral, covering the whole height of the plate while the secondaries are much smaller. Test: Flattened above and below, rather fragile, but not flexible. Apical system: Hemicyclic, ocular plates II and III exsert. Ambulacra: Narrow, pore pairs in steep arcs of three, more or less widened toward the peristome; tubercles in two regular series, disappearing adapically.

4.2.3 Order Diadematoida Duncan, 1889 

 169

Interambulacra: Two regular series of large primary tubercles; secondaries much smaller. Peristome: Broad, rounded buccal notches; shallow indentations in the ambulacra also; buccal plates set with spines and pedicellariae. Primary spines: Mostly long and slender, hollow and very brittle, shaft verticillate; in C. longispinus and C. coronatus, small club-shaped spinelets adapically. Literature: Koehler 1927; H. L. Clark 1914, 1921; Mortensen 1940; Bernasconi 1955; Pearse 1972; Fell 1975; Nelson & Vance 1979; Pawson & Miller 1979, 1983; Vance 1979. Nine species of Centrostephanus are known, distributed worldwide: Centrostephanus asteriscus A. Agassiz & H. L. Clark, 1907. Hawaii and Malayan region. Centrostephanus besnardi Bernasconi, 1955. Island of Trinidad, off Brazil. Centrostephanus coronatus (Verrill, 1867). Gulf of California. Centrostephanus longispinus (Philippi, 1845). East Atlantic and Mediterranean. Centrostephanus nitidus Koehler, 1927. Maldives, Indian Ocean. Centrostephanus rodgersii (A. Agassiz, 1863). East coast of Australia to New Caledonia. Centrostephanus rubricingulus H. L. Clark, 1914. Caribbean from Florida to Venezuela. Centrostephanus sylviae Fell, 1975. Endemic to San Felix Island and Mas a Tierra, Southeast Pacific. Centrostephanus tenuispinus H. L. Clark, 1914. Centrostephanus asteriscus A. Agassiz & H. L. Clark, 1907 (Fig. 4.97) Test: Flattened; diameter of test may reach more than 50 mm. Apical system: Oculars in young specimens narrowly insert in touching elongated periproctal plates, which extend between the genital plates. Interambulacra: Distinct secondary tubercles, not only at the ambitus, but also orally, carrying long and very slender secondary spines. Color: The test is reddish; in the Hawaiian form, the additional periproctal plates form a distinct white star. The spines are banded in red. The specimens from the Malayan region, var. malayanus, show a light green on the denuded test; the white star is rather inconspicuous, and the spines are banded in red or green tint. Distribution: Found in the west and central Pacific from the Malayan region and the southern China Sea to Hawaii, at depths of 60 to 315 m.

170 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

Fig. 4.97: Centrostephanus asteriscus. (A) Aboral side of test, diameter 36 mm; Negros, Philippines (photos by Bas van der Steld). (B) Oral side of test: the buccal membrane is covered by small elongated platelets. (C) Aboral side with spines, diameter of test 32 mm; Negros, Philippines. The primary spines are banded and strongly verticillate. All spines are very brittle.

Centrostephanus besnardi Bernasconi, 1955 Two rather young specimens with a test diameter of 18 and 12 mm. Apical system: Plates naked, only ocular ones set with a single tubercle. Color: Spines banded in white and rose. Occurrence: The sole specimen was found at the Island of Trinidad, off Brazil. Remark: Fell (1975) could not find any reliable difference between the three Atlantic species except their locality. He proposed to make C. bernardi and C. rubricingulus to subspecies of C. longispinus. Centrostephanus coronatus Verrill, 1867 (Fig. 4.98 A, B) Test: Large, reaching more than 60 mm in diameter. Apical system: Club-shaped spinelets adapically present. Ambulacra: Only the two uppermost tubercles are lacking adapically; ambital primary tubercles almost as large as in interambulacra; correspondingly, the triads of pore pairs are bent around the areoles; on the oral side, broad bands of pore pairs widening at the peristomial edge. Interambulacra: Two rows of primary tubercles, series of smaller secondaries around the ambitus. Spines: Robust, though brittle, rather coarsely verticillate. Color of spines: Banded in younger specimens, but in large tests, unbanded in dark purple to black with lighter bases. Distribution: From Baja California and the Gulf of California, Mexico, to Panama, littoral form. Biology: Centrostephanus coronatus strongly influences the biodiversity of its habitat by its grazing. It lives in crevices or holes on rock or among boulders coming out for

foraging usually at night, when the sheephead wrasse Pimelometopon pulchrum, a main predator, has retired. Each urchin travels less than 1  m from its shelter and returns to the same one before sunrise. Centrostephanus longispinus Philippi, 1845 (Fig. 4.98 C, D) Test: Rather thin; low, circumference round or subpentagonal; diameter of test up to 63 mm. Apical system: Ocular plates broadly insert, but separated from the periproct by one or more irregular plates; madreporite enlarged; plates with rather few tubercles. Ambulacra: Primary tubercles about as large as interambulacral ones, disappearing abruptly above the ambitus; alternating, small tubercles at the inner edge of the plates; pore pairs on the aboral side in a straight line, but from the ambitus downward in distinct arcs of three and at the peristomial edge crowded. Interambulacra: Single primary tubercle in the middle of each plate, disappearing close to the apical system; along the outer edge one or two series of considerably smaller secondary tubercles from peristome almost to the apical system and very small irregular ones at the inner edge. Peristome: Dense series of transversely elongated plates in ambulacral position, few scattered ones in interambulacral position; ambulacral median sutures as indented as the buccal notches. Spines: Hollow and fragile; ambital and supra-ambital primary spines nearly twice the test diameter, oral primaries shorter and slightly widened distally; small adapical primaries club-shaped. Color: The test is dark violet brown with a whitish line along the midlines of both ambulacra and interambulacra, which does not continue to the apical plates. The test may also be pale yellowish. The spines are banded in purple,

4.2.3 Order Diadematoida Duncan, 1889 



A

C

B

D

 171

E

Fig. 4.98: (A, B) Centrostephanus coronatus. (A) Aboral side of test, diameter 60 mm; Coronado Island, Mexico. ZMUC. (B) Side view with spines, diameter of test ca. 63 mm; Coronado Island, Mexico. ZMUC. The spines are robust and strongly verticillate. (C, D) Centrostephanus longispinus. (C) Aboral side of test, diameter 40 mm; West Africa. The tubercles of the adapical interambulacral plates are much reduced in size. (D) Close-up of apical area, test diameter 37 mm; West Africa. Here the typical club-shaped spines are positioned. The living animal keeps the small, vividly red spines in constant rotation. They are likely to have a sensory function. (E) Centrostephanus nitidus. Aboral side with the bright red primary spines, diameter of test 67 mm; Maldives. ZMUC.

green, or yellowish white. The distal ends of the short, clubshaped primaries around the apical system are a vivid red. The bare test has a green color, fading gradually toward the peristome, sometimes with a pink tint over the upper side. Biology: The club-shaped, red spines around the apical system, already present in young specimens, are kept in constant rotation. It is likely that they have a sensory function. Distribution: Centrostephanus longispinus is known from the Mediterranean and the East Atlantic from the Cape Verde Islands, Morocco, and the Azores at depths of 50 m to more than 200 m. In the east Mediterranean, it is reported from shallow water (H. Moosleitner, personal communication). Centrostephanus nitidus Koehler, 1927 (Fig. 4.98 E) This species differs from all other species of Centrostephanus by its unbanded, intensely red primary spines.

Test: Flat, slightly sunken in the apical region; reaching a diameter of 47 mm. Apical system: Ocular plates at least as large as genital plates; periproctal plates tiny. Ambulacra: Tubercles as large as in interambulacra, 3–4 adapical plates without tubercles; pore zones slightly widened adorally. Interambulacra: Primary tubercles relatively small, the two uppermost plates without tubercles. Spines: Primary spines very slender; in length, twice the test diameter; adoral primary spines as slender as secondary ones. Color: The test varies from almost black to light with a dark gray band along the interambulacral median suture continuing over the genital plates to the periproct. Usually, there is a white midline in these dark stripes. The well-cleaned test is a creamy white with green or reddish tint adapically.

172 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

Fig. 4.99: (A–C) Centrostephanus rodgersii. (A) Aboral side of test, diameter 76 mm; Northland, New Zealand. Around the apical system, the primary tubercles are rudimentary. (B) Oral side of test: the tubercles are much smaller than on the upper side, but more numerous. (C) Side view with spines, diameter of test 35 mm; Sydney Harbour, New South Wales, Australia. (D) Centrostephanus tenuispinus. Side view, diameter with spines approximately 50 mm; Houtman Abrolhos Island, Western Australia. This species has longer and more slender spines than Centrostephanus rodgersii.

Distribution: The species is found off Burma and the Maldives. Bathymetric range 160 to 229 m. Centrostephanus rodgersii A. Agassiz, 1863 (Fig. 4.89 B, 4.99 A–C) Test: Low, diameter of test may reach up to 100 mm. Apical system: Conspicuously sunken; periproct large and circular, with larger plates around the outer edge, the inner membrane covered with small platelets.

Ambulacra: Pore pairs in arcs of three, on the aboral side, steeply arranged; on the oral side, much lower; adorally distinctly widened as phyllodes; primary tubercles in two regular series, rather large, absent near the apical system. Interambulacra: Two series of large primary tubercles with, on either side, more or less regular series of distinctly smaller secondaries; tubercles around the apical system reduced, very few miliary tubercles aborally.



Peristome: Usually sunken, larger than apical system; buccal notches shallow and rounded. Spines: Primary spines in diameter about 3  mm with 30–40 wedges, robust looking, but hollow and rather brittle, thick at the base, tapering distally; set with very fine thorns; length in large specimens, half the diameter of test; in smaller ones, relatively longer. Color: The spines are in life dark purplish to almost black; the denuded test is white with a faint purplish tint; at the apical system, it may be faintly greenish. Biology: Centrostephanus rodgersii lives concealed under rocks or in crevices during daytime and comes out to feed at night, grazing mostly on algae or encrusting organisms. Distribution: This species occurs around the east coast of Australia from Queensland to Tasmania and from Lord Howe Island to New Zealand and New Caledonia. It is restricted to the littoral zone. Centrostephanus rubricingulus H. L. Clark, 1914 Test: Diameter hardly reaches 20 mm. This nominal species well resembles C. longispinus especially in having the small, bright red, club-shaped spines on the upper side. C. rubricingulus is likely to be a West Atlantic subgenus of C. longispinus differing in its almost black spines (as also C. besnardi). The East Atlantic form C. longispinus longispinus has banded primary spines. Distribution: Caribbean from off Florida  – Gulf and Atlantic – to Venezuela. Depths of about 30 to 300 m. Centrostephanus sylviae Fell, 1975 This species is very nearly related to the two other South Pacific species. It differs from C. rodgersii, by the more slender spines: in diameter 2 mm with 20–31 wedges, and from C. tenuispinus, by the lack of larger tubercles on the apical plates. Distribution: The species is known only from the Juan Fernandez Islands (Chile). Depth 9 to 75 m. Centrostephanus tenuispinus H. L. Clark, 1914 (Fig. 4.99 D) This species resembles Centrostephanus rodgersii, but its long spines are more slender, only 2 mm in diameter with 20–31 wedges. Each apical plate is set with at least one larger tubercle. It is endemic to southwest Australia, from South Australia to Shark Bay on the west coast, in contrast to Centrostephanus rodgersii, which is known from the east coast, Tasmania, and New Zealand. Genus Chaetodiadema Mortensen, 1903 This genus is immediately recognizable by its wheel-shaped test, the upper and underside being broadly flattened with

4.2.3 Order Diadematoida Duncan, 1889 

 173

more or less steep sides. The inner part of the oral side is more or less set with very small, densely arranged tubercles carrying extremely fine spines. (Mortensen 1940 called these areas “bearded”.) Test: Very low and wheel-shaped, fragile with imbricating sutures, flexible. Apical system: Large; genital plates more or less extending into the interambulacra and pointed; periproct large. Ambulacra: Narrow; mostly 3 pore pairs per plate, widely spaced toward the peristome, the plates being high and becoming non-compound with a single pore pair; two series of primary tubercles, which disappear toward the apical system. Interambulacra: Upper side with more or less V-shaped, naked areas; larger tubercles only at ambitus; on oral side, with fine granulation of minute tubercles. Peristome: Small and sunken, distinct buccal notches. Spines: Long and slender, set with fine thorns; on oral side increasingly fine and close-set toward the peristome (Mortensen 1940 called these inner areas “bearded”). In life, the species of Chaetodiadema display blue spots or lines, which are light receptors as in Astropyga. Outlines or impressions remain on preserved tests as darker spots, which are yellowish in bare tests. The genus consists of six species: Chaetodiadema africanum H. L. Clark, 1924, tropical South Africa. Chaetodiadema granulatum Mortensen, 1903, Indo-West Pacific to northern Australia. Chaetodiadema japonicum Mortensen, 1904, southern Japan, 50 to 135 m. Chaetodiadema keiense Mortensen, 1939, Moluccan region to Queensland, Australia. Chaetodiadema pallidum A. Agassiz & H. L. Clark, 1907, restricted to Hawaii. Chaetodiadema tuberculatum H. L. Clark, 1909, restricted to New South Wales, Australia. The species differ in the development of pore pairs on the oral side: three pairs on compound plates or a single pair on simple plates; the extension of the ambulacral primary tubercles on the upper side, in the distribution of the blue spots. Chaetodiadema africanum H. L. Clark, 1924 (Fig. 100 A) Test: Diameter may reach 45 mm. Apical system: Rather naked; genital plates pointed, ocular plates broadly insert. Ambulacra: Two series of regularly arranged primary tubercles, disappearing on the aboral side on fifth to sixth plate from the apical system; on most of the oral side, ambulacral plates high and with a single pore pair, only

174 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

E

F

Fig. 4.100: Ambulacral plates of species of Chaetodidema on the oral side. (A) Chaetodiadema africanum: the primary tubercles are traceable down to the peristome. (B) In Chaetodiadema granulatum, the oral plates are densely covered by minute, close-set tubercles. Toward the peristome, the pore pairs become smaller and more widely spaced. (C) Chaetodiadema japonicum: the last 7 or 8 plates toward the peristome are not compound, carrying only a single pore pair. (D) Chaetodiadema keiense. The alternating series of primary tubercles reaches down to the peristomial edge. (E) Chaetodiadema pallidum: the granules are less densely distributed. (F) Chaetodiadema tuberculatum. There are simple ambulacral plates. Scales: (A, C, D, F) 4 mm; (B) 6 mm; (E) 5 mm (Mortensen 1940). The peristomial edge is at the bottom.

near the ambitus compounded plates with 3 pore pairs arranged in indistinct arcs. Interambulacra: On aboral side, primary tubercles form only short series, leaving V-shaped naked areas medially; on oral side, primary tubercles traceable to the peristome, no conspicuously fine granulation. Spines: Long and very slender, thorny, on oral side additionally fine miliary spines. Color: Adult specimens, pinkish; younger ones rather white with green tints. Blue iridescent lines along the naked areas in the interambulacra, a spot below each genital pore. Distribution: Off Natal, South Africa, and Pemba Strait, East Africa. Bathymetric range 85 to 325 m. Chaetodiadema granulatum Mortensen, 1903 (Fig. 4.100 B, 4.101 A–C) Test: Diameter may reach 90 mm. Apical system: Tuberculation concentrated along the periproctal edge, distally rather naked. Ambulacra: Aboral pore pairs in distinct arcs of three, forming a broad band; two regular series of primary tubercles; on oral side, disappearing abruptly toward the peristome; aborally reaching only halfway toward the apical disc. Interambulacra: Up to 6 large tubercles per plate at the ambitus, abruptly decreasing in size adorally, forming a very small and densely set granulation.

Spines: Long and very slender, on oral side fine like a “beard”. Distribution: The species is found in the Indo-West Pacific from the Macclesfield Bank, South China Sea, through the Philippines and the Malayan Archipelago to the northern coast of Australia at depths of 38 to 84 m. Remark: Distinguished from the other species of Chaetodiadema in having the blue lights on the aboral interambulacra – the yellowish marks on the bare tests, respectively – in isolated spots, not in lines. There is also an iridescent spot mark immediately below the genital pores. Chaetodiadema japonicum Mortensen, 1904 (Fig. 4.100 C, 4.101 D–E) Test: Sunken toward apical disc and peristome; diameter may reach more than 70 mm. Apical system: Ring of large plates around the anal opening with protruding cone. Ambulacra: Pore pairs in almost straight lines; adorally about 15 simple plates. Interambulacra: Distinct bifurcating naked areas on the aboral side, large primary tubercles only around the ambitus, up to four per plate; adorally decreasing in size and number; secondary tubercles very small and, especially on the oral side, very numerous.

4.2.3 Order Diadematoida Duncan, 1889 



A

 175

C

E

B

D

Fig. 4.101: (A–C) Chaetodiadema granulatum. (A) Aboral side of test, diameter 77 mm; Philippines. ZMUC. The yellowish markings of the blue lights along the naked areas are very distinct; the isolated spots are typical for this species. (B) Oral side. (C) Side view: the test is wheel-shaped. (D–E) Chaetodiadema japonicum. (D) Aboral side of test, diameter 41 mm, height 11 mm; Japan. The dark lines mark the blue iridescent lights. There are additional dark spots below each gonopore (sketch after a photo of V. T.). (E) Oral side with spines, diameter of test about 51 mm; Japan. ZMUC.

Spines: Short and slender, finely thorny rather than verticillate. Color: The test is aborally yellow brown or light red brown; the underside is light. There are conspicuously dark lines along the bifurcated naked interambulacral areas, which

mark the blue iridescent lines of the living sea urchin. The spines are banded in red brown and yellow green. Distribution: The species is restricted to Japanese waters from Sagami Bay to off the Goto Islands. Bathymetric range 50 to 135 m.

176 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

Fig. 4.102: (A, B) Chaetodiadema keiense. (A) Aboral side of test, diameter 29 mm; Kei Islands, Indonesia. ZMUC ECH 205. (B) Oral side: the larger primary tubercles reach down to the peristome. The apical system is relatively large. The blue, iridescent areas remain as radial yellow bands or spots on bare tests. (C, D) Chaetodiadema pallidum. (C) Aboral side, diameter of test 61 mm, height 16 mm; Hawaii. (D) Oral side: around the small, sunken peristome the tubercles are very small.

Chaetodiadema keiense Mortensen, 1939 (Fig. 4.102 A, B) Test: Maximum diameter 35 mm. Apical system: Prolongation of genital plates rather narrow, the pore in the tip on a crater-like wall; all plates with numerous small tubercles; in larger specimens, the whole apical system may be distinctly raised.

Ambulacra: On upper side, primary tubercles on each compound plate forming rather regular, but distant series; on oral side, primary tubercles decrease gradually in size but are traceable almost to peristome. Interambulacra: Two large tubercles per plate at ambitus, which disappear just a little above the ambitus; the whole oral



side being covered by heterogeneous, rather coarse tuberculation; on the upper side numerous, very small tubercles; the bifurcating naked space hardly reaching the ambitus. Peristome: Sunken, small; buccal notches small. Spines: Ambital primary spines long and slender, flattened distally. Color: The iridescent lights in the interambulacra form a line and there is a spot mark below the genital pores. The test is beige with a faint greenish tinge. The primary spines are distinctly banded. Distribution: This species was found off the Kei Islands, Indonesia. Depth 200 to 250 m. Chaetodiadema pallidum A. Agassiz & H. L. Clark, 1907 (Fig. 4.102 C, D) Test diameter may reach more than 60 mm. Ambulacra: Adorally only 6 simple plates with 1 pore pair, compound plates with steep arcs of three beginning already with the seventh pore pair; primary tubercles adapically lacking. Occurrence: Endemic to the Hawaiian Islands. Bathymetric range 50 to 400 m. Chaetodiadema tuberculatum H. L. Clark, 1909 Main characteristics of the genus. Ambulacra: Primary tubercles on aboral side beginning on the second to third plate; most of oral side set with simple plates perforated by a single pore pair, compound plates with steep arcs of three only near the ambitus. Distribution: Endemic to New South Wales, Australia. Bathymetric range 115 to 630 m. Genus Diadema Gray, 1825 The genus consists of six species widespread in shallow tropical waters. In these habitats, they are the ecologically most important sea urchins due to their intensive grazing. They occur in large herds, in open, but sheltered places between the corals, usually crowded together by day and separating by night to feed. These sea urchins are also common near human settlements, e.g. in harbors, where they have access to a rich food supply. Test: Low, outline circular to rounded pentagonal with flattened apical disc and sunken peristome. Apical system: Hemicyclic and monocyclic; genital plates pointed, madreporite conspicuous; periproctal membrane naked except of scattered scales, distinct anal cone. Ambulacra: 3 pore pairs per plate, pore zones widened adorally; one primary tubercle per plate, smaller than in interambulacra, forming very regular series, no secondary tubercles.

4.2.3 Order Diadematoida Duncan, 1889 

 177

Interambulacra: Regular series of primary tubercles from peristome nearly to the apical system, up to four equal-sized secondary tubercles per plate on the median space, more or less broad naked areas along the aboral midline. Peristome: 5 pairs of buccal plates, notches present, ambulacral edges indented. Spines: Long, slender, verticillate, and hollow; secondary spines much smaller than primary ones. There are conspicuous iridescent blue or white lines and spots on the apical plates and along the interambulacral median line, often marked by slight depressions on the cleaned test. Remark: The genus is distinguished from Echinothrix by the arrangement of the tubercles in the ambulacra: in Echinothrix, the aboral interporiferous zone is widened, leaving space for densely set secondary tubercles not much smaller than the primaries, whereas in Diadema, there are two parallel series of primary tubercles without secondaries. There are six described species in this genus. Diadema antillarum (Philippi, 1845). Subtropical and tropical Atlantic from Florida to Brazil, the Azores and Canaries to the Gulf of Guinea, West Africa, littoral, including Diadema ascensionis Mortensen, 1909. Subspecies of D. antillarum, South Atlantic. Diadema mexicanum A. Agassiz, 1863. Tropical western coast of the Americas from the Cortez Sea, Mexico, to the Galapagos Islands, littoral. Diadema palmeri Baker, 1967. Southeast Australia and New Zealand, littoral. Diadema paucispinum A. Agassiz, 1863. Indo-Pacific from East Africa to Hawaii, littoral. Diadema savignyi Michelin, 1845. Indo-Pacific from East Africa to the Tonga Islands, littoral. Diadema setosum Leske, 1778. Indo-Pacific from East Africa to Easter Islands, littoral. Caution: All species of Diadema possess long, pointed spines, which are a serious danger for swimmers and divers. The spines themselves are not poisonous, but the translucent distal ends easily penetrate human skin, shattering in the wound. It is virtually impossible to remove them (except by a surgery). Intensely painful infections may be the result because the spines often transfer organic debris and bacteria into the wound. Native people in the tropics apply fresh lemon juice to the wound to ease the pain and avoid infection. Literature: A. M. Clark & Rowe 1971; Serafy 1979; Lessios 1984; Shigei 1986; Rowe & Gates 1995; Pearse 1998; Lessios et al. 2001; Coppard & Campbell 2004, 2005, 2006.

178 

 4.2 Subclass Euechinoidea Bronn, 1860

Diadema antillarum

Diadema mexicanum

Diadema palmeri

Iridophore pattern on genital plates

Faint blue arch

Faint blue arch

Bold blue/turquoise arch

Marking on naked test

Arch-shaped impression

Arch-shaped impression

Arch-shaped impression

Iridophore pattern on median line in interambulacra

By night, faint white spot

By night, faint white spot

Naked triangular area cream colored

Marking on naked test

No marking

Faint marking

Large naked triangular area

Anal cone

Black

Black

Red, black ring and white platelets

Diadema paucispinum

Diadema savignyi

Diadema setosum

Iridophore pattern on genital plates

No iridophore

Bold blue arch

Blue spot

Marking on naked test

No impression

Arch-shaped impression

Spot-like impression

Iridophore pattern on median line in interambulacra

By night light brown spot

By night white spot

Day and night: white line and spot

Marking on naked test

No marking

Variably white spot/no spot

White line and spot marking

Anal cone

Black

Black

Black with orange ring

Diadema antillarum Philippi, 1845 (Fig. 4.103) Test: Diameter up to 110 mm. Apical system: Slightly depressed; usually ocular plates II and III exsert; in large specimens, often all insert; 2–4 small tubercles on genital plates. Ambulacra: Narrow, more or less inflated; pore pairs arranged vertically on aboral surface, but slightly widened adorally. Interambulacra: Two series of large primary tubercles, between them shorter rows of almost equal-sized secondary tubercles, up to four per plate; adapical naked space at median line depressed, narrow, and rather inconspicuous. Peristome: Much larger than apical system; buccal notches broad and deep; buccal membrane and plates naked. Spines: Very long, slender, hollow, and fragile, can reach lengths of 300 to 400  mm, up to 4 times the test diameter; shaft covered with many whorls of spinelets (verticillate). Color: Spines and test are typically black, but individuals may have few gray or white spines, some can be almost entirely white. Cleaned tests are uniformly white; the anal cone simply black. Iridophore pattern: Blue lines in the interambulacra, white spot in the naked median area, blue arch on genital plate, but the colors are much less conspicuous than in Diadema setosum. The markings on the naked test are indistinct.

Biology: This species is gregarious, often occurring in very large numbers, 20 individuals and more may be found per square meter. It can move rapidly. Generally, Diadema antillarum remains in crevices during the day, coming out at night to graze on encrusting organisms found on corals, stones, etc. It prefers sheltered waters in reefs, turtle grass beds, or mangroves, actively avoiding places of heavy wave action. Distribution: Diadema antillarum is known from the western Atlantic, from the Gulf of Mexico, Bermuda, and Florida through the whole Caribbean and southward to Rio de Janeiro. In the eastern Atlantic, it lives from the Azores, Madeira, the Canaries, and the Cape Verde Islands, to the Gulf of Guinea, West Africa. Bathymetric range 0 to 40 m. Biogeographical remark: Diadema antillarum, distributed in the Atlantic, is very similar to Diadema mexicanum from the west coast. It is not only their shape and color that are similar, but also their biochemistry, which shows that the two congeners have formerly been one species. When the continental plates of the two Americas met in the Pliocene, and the Isthmus of Panama raised, the waterway was closed, separating the populations. Gradually, they developed into two different species, one in the Caribbean and Atlantic and one in the Pacific. This development is also recognizable in several other genera, for instance, in Eucidaris, Echinometra, and Mellita (Lessios 1984).

4.2.3 Order Diadematoida Duncan, 1889 



A

 179

B

D C

Fig. 4.103: Diadema antillarum. (A) Aboral side, diameter 56 mm; Dominican Republic. (B) Side view. (C) Oral side: the buccal notches are broad. (D) Aboral side with spines, diameter of test about 24 mm; Barbados. The primary spines of this specimen are black and whitish, while those on the oral side are more grayish. Rarely, the spines may be entirely white.

Diadema mexicanum A. Agassiz, 1863 (Fig. 4.104 A) This species is very similar to Diadema antillarum. Test: Rounded pentagonal. Maximum test diameter 92 mm. Apical system: Anal tube black, sometimes with whitish ring around opening of anus. Pattern of iridophores: Faint white spot in the median part of the interambulacra, blue lines may be interrupted, sometimes with small branches expanding between the secondary tubercles. Usually, there is also a fine blue arch on the genital plates. The markings on the naked test are visible. Color: In contrast to other species of Diadema, the spines remain banded in adults. Distribution: Diadema mexicanum lives along the west coast of America from the Gulf of California to the Gulf of Panama, including the outlying islands and, more

southward, the Galapagos and Easter Islands, from the littoral zone to a depth of about 40 m. Diadema palmeri Baker, 1967 (Fig. 4.104 B, C) Test: Round, maximum test diameter 78 mm. Apical system: Monocyclic (in contrast to the other species of Diadema), ocular plates being all insert; periproctal edge of genital plates with 2–6 small tubercles, may be distinctly raised; periproctal membrane with scattered scales, anal cone large. Interambulacra: Two regular series of primary tubercles extending nearly to the apical system, inner series of large tubercles reaching to the fifth or sixth plate at the upper side, leaving a triangular naked area medially bifurcating between the two series of each column. Peristome: Distinct buccal and ambulacral notches.

180 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C D

Fig. 4.104: (A) Diadema mexicanum. Aboral side with spines, diameter of test 37 mm; Manzanillo, Mexico. ZMH. The spines remain banded in adults. The white ring surrounding the anus is distinct. The spines are broken and have not their full length. (B, C) Diadema palmeri. (B) Aboral side with spines, test diameter 31 mm; Kermadec Islands, Southwest Pacific. ZMUC. (C) Diadema palmeri. Aboral side of test, diameter 30 mm; Kermadec Islands. The median area in each interambulacrum forms a conspicuous cream yellow triangle. (D) Diadema paucispinum. Aboral side with the large anal sac, diameter 55 mm; Hilo, Hawaii. ZMUC.



Color: Test crimson red, periproct and peristome grayish pink, anal cone reddish with white platelets and with a black ring; median naked triangle in interambulacra conspicuously cream with some red spots; primary spines banded in red and white, secondary spines red. The well-cleaned test is whitish. Pattern of iridophores: Lines and spots in brilliant blue turquoise and lilac, on the apical plates in bold arches and a ring, and running down the naked areas between the two rows of large tubercles reaching almost the peristomial edge; naked test shows distinct arched depressions on genital plates. Distribution: This species is known from New Zealand, over the Kermadec Islands and the Tasman Sea to the east coast of Australia. Bathymetric range 10 to 50 m. Diadema paucispinum A. Agassiz, 1863 (Fig. 4.104 D) Test: Diameter may reach 92 mm. Apical system: Hemicyclic; 2–6 small tubercles along the periproctal edge of genital plates. Ambulacra: Two regular series of tubercles, lacking on the uppermost plates. Interambulacra: Fewer coronal plates and correspondingly fewer primary spines per column: in D. paucispinum, 12–14 plates against 15–16 in a specimen of D. setosum of same size; the naked area is small and inconspicuous. Color: Black, naked tests are white; younger specimens having a red tinge. Pattern of iridophores: No iridophores are developed on the apical system, and the blue line in the interambulacra is faint. At night, one may observe a light red brown spot. There are no visible markings on the naked test. Distribution: Mortensen (1940) thought this species to be endemic to the Hawaii Island. Lessios et  al. (2001) examined the genus by molecular-genetic analyses and found out that D. paucispinum is widely distributed from Durban, South Africa, and the Arabian Peninsula through the Malayan Archipelago, the Philippines, and Okinawa to New Guinea, and further eastward in the entire Central Pacific from Hawaii to Pitcairn and the Easter Islands. The species is a littoral form. Diadema savignyi Michelin, 1845 (Fig. 4.105 A–C) Test: Generally reaches a diameter of 60  mm, exceptionally up to 100 mm. Apical system: Up to 3 small tubercles along the periproctal edge on genital plates. Ambulacra: Hardly widened adorally. Interambulacra: Two regular series of primary tubercles, secondaries subequal, usually 4 to 5, exceptionally 6 vertical series at ambitus; adapically naked, depressed median zones. Spines: Primaries very long, up to 300  mm or more, slender and hollow, verticillate.

4.2.3 Order Diadematoida Duncan, 1889 

 181

Color: Test and spines black; anal tube black; spines in young specimens often banded; cleaned tests are white. Pattern of iridophores: Conspicuous blue ring across the apical plates, bold blue arch on each genital plate, in the interambulacra bold blue lines border more or less distinct white spots or lines. On the naked test, the depressed arches on the genital plates are distinct. Distribution: The species is reported from East Africa, from the Red Sea to Natal; eastward to the South Pacific Islands and Easter Islands; from Japan to Australia. The sea urchins are found from the littoral to depths of about 70 m and live in mixed populations with Diadema setosum, prefering more exposed waters. Diadema setosum Leske, 1778 (Fig. 4.105 D–F) The species very much resembles to D. savigny. Test diameter up to 90 mm. Apical system: 3–5 small tubercles on genital plates. Color: Test and spines are usually black; they may be also brown, gray, or even white; the spines of younger specimens banded in black and white; cleaned tests are white. Pattern of iridophores: Isolated bright blue spot in each genital plate, a white spot lies halfway down on each interambulacrum, sometimes more or less as a band along the median line of the naked zones. On the naked test, distinct depressed spot-shaped marking below each genital pore. The anal tube is ringed by a conspicuous red orange band, visible also in daylight. Biology: Diadema setosum lives in sheltered water from the littoral zone to a depth of about 70  m. Like other species of Diadema they graze on encrusting organisms. Some fish are able to prey upon this spiny creature: they blow a current of water against the sea urchin to lift and overturn it. Then the predator can reach the less welldefended oral side and can attack the test. Distribution: Diadema setosum is known in the whole Indo-West Pacific region from the East African coast to Australia and from Japan to Tonga, but not further east. Genus Echinothrix Peters, 1853 The genus consists of two species: Echinothrix calamaris Pallas, 1774 Echinothrix diadema Linné, 1758 Both the species are very common in their wide area of distribution from the Red Sea to the South Pacific Islands. They often co-occur with Diadema setosum and D. savignyi. Caution: The thin secondary spines contain a poison in their very fragile distal ends, which can cause painful injuries. One may find them between corals or on rocky bottoms. The denuded tests of all four species look very similar at first sight.

182 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

E

F

Fig. 4.105: (A–C) Diadema savignyi. (A) Oblique view, length of spines ca. 100 mm, test diameter 20 mm; Sydney Harbour, Australia. The spines are uniformly black set with very fine thorns. (B) Close-up of aboral side with spines: the bright blue iridescent lights are strongly developed, passing not only along the median zones but also extending over the whole interambulacra (photo by H. Moosleitner). (C) Apical system: below each gonopore lies a shallow arc-shaped depression. (D–F). Diadema setosum. (D) Apical system: there is a depressed spot below each gonopore. (E) Aboral side of test, diameter 54 mm; Negros, Philippines. The tip of the anal tube is red. (F) Side view of test. Scales: (C, D) 2 mm (Mortensen 1940).

4.2.3 Order Diadematoida Duncan, 1889 



 183

Echinothrix calamaris

Echinothrix diadema

Diadema setosum and Diadema savignyi

Ambulacra widened adapically and strongly inflated, two series of primary tubercles with 4–6 subequal secondaries in interporiferous zone

Ambulacra widened adapically, slightly or not inflated, two series of primary tubercles with several subequal secondaries in interporiferous zone

Ambulacra narrow, slightly inflated, two series of primary tubercles, but no secondaries in interporiferous zone

Adapical median zone in interambulacra naked and usually green

Adapical median zone in interambulacra not naked and never green

Adapical median zone in interambulacra naked

Periproctal membrane and large anal tube with many small, but very conspicuous, white spots

Periproctal membrane black, anal tube of moderate size and rather inconspicuous

Periproctal membrane and distinct anal tube black, bright red ring around the opening (only in D. setosum)

Echinothrix calamaris Pallas, 1774 (Fig. 4.106 A, B) Test: Flattened above and below, outline circular to rounded pentagonal, diameter up to 160 mm. Apical system: Sunken, ocular plates all insert, genital plates projecting into interambulacra; periproct large with peripheral plates, anal cone and membrane with very conspicuous, small white spots. Ambulacra: Widened and inflated aborally; two series of primary tubercles, the median space is densely filled with 4–6 subequal tubercles; narrower on the oral side with larger primaries and much smaller and fewer secondaries; pore pairs in arcs of three, pore zones at the peristome widened. Interambulacra: Two vertical series of primary tubercles from the peristome extending almost to the apical system, around the ambitus and on the oral side more series of equal-sized secondaries, creating adapical conspicuous, naked zones in the median area. Peristome: Much larger than apical disc, membrane naked, buccal notches deep, and rounded with associated tags. Spines: Interambulacral spines rather solid, long, and hollow, with fine thorns; ambulacral ones thin and fragile. Color: This species has a very large range of color variation. The spines may be banded in black and white, or uniformly white or black, or with greenish bands. In life, the test usually appears dark greenish with more or less bright green in the interambulacra or, more rarely, purplish, or test and spines are wholly brown. The denuded test is tinted green or purplish in the naked areas. Distribution: Echinothrix calamaris is known from the Red Sea and East Africa to the Malayan Archipelago, from south Japan to north Australia and the South Pacific Islands in the littoral zone. Echinothrix diadema Linné, 1758 (Fig. 4.106 C, D) Test: Flattened above and below; outline circular or slightly pentagonal; diameter up to 100 mm.

Apical system: Only slightly sunken or flush; all ocular plates insert; genital plates expanding into interambulacra; periproctal membrane black, anal tube rather inconspicuous. Ambulacra: Widened on the aboral side, two series of primary tubercles; in the median zone, two to four series of slightly smaller secondaries; 3 pore pairs in an arc, pore zones widened toward the peristome. Interambulacra: 4–6 vertical series of large, subequal tubercles at the ambitus, no distinct naked median zones. Peristome: Much larger than apical system; deep, rounded buccal notches with tags, ambulacral median suture also indented. Spines: In interambulacra, solid, long, and hollow; in ambulacra, much smaller, thin, and very fragile. Color: The primary spines are light brown with white tips, entirely black or rarely banded. In life, the secondaries are dark with purple tips (containing poison). The denuded test is whitish. Distribution: This species is widely spread through the whole Indo-West Pacific, from the Red Sea and East Africa to Tahiti and the Tuamotu Islands and from south Japan to north Australia, living in the littoral zone. Genus Eremopyga A. Agassiz & H. L. Clark, 1908 Two species are included in this genus: Eremopyga debilis Mortensen, 1940, Philippines. Eremopyga denudata (de Meijere, 1902), Philippines to northern Australia. They differ in the arrangement of the tubercles on the oral side: in E. debilis, large primary tubercles are only developed on the distal part, resembling Chaenodiadema. In E. denudate, the primary tubercles continue toward the peristome. Eremopyga debilis Mortensen, 1940 (Fig. 4.107 A, B) Test: Large, low, but not sunken; more or less flexible with imbricating plates; extremely thin and fragile; diameter up to 84 mm.

184 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

Fig. 4.106: (A, B) Echinothrix calamaris. (A) Aboral side, diameter over spines about 110 mm; Cebu, Philippines (photo by W. Clarenbach). (B) Aboral side of test, diameter 62 mm; Negros, Philippines. The ambulacra are broad and inflated, the naked interambulacral median space being green. The large black anal tube is covered by small white spots. (C, D) Echinothrix diadema. (C) Aboral side of test, diameter 72 mm; Negros, Philippines. There is no naked area in the interambulacra. (D) Aboral side with spines, diameter of test 52 mm; South Pacific. ZMH. The anal tube is small, black, and indistinct.

4.2.3 Order Diadematoida Duncan, 1889 



A

 185

B

D

C

E

Fig. 4.107: (A, B) Eremopyga debilis. (A) Aboral side of test, buffered. Diameter 76 mm; Mindanao, Philippines. ZMUC. Large primary tubercles are present only around the margin, aborally they are almost lacking. (B) Oral side of test: the large primary tubercles disappear abruptly toward the peristome. (C–E) Eremopyga denudata. (C) Aboral side, partly with spines, diameter 81 mm; Bali, Indonesia. ZMUC. The ambulacra and adjacent interambulacra are particularly inflated, correspondingly the bifurcating, naked areas are sunken. The blue iridescent lights are marked by broad dark lines. (D) Oral side of denuded test, diameter 92 mm; Indochina. ZMUC. In contrast to Asteropyga, the ambulacra do not widen toward the peristome. (E) Side view: the median, bifurcating area in the interambulacra is distinctly sunken, but not as much as in specimen C.

186 

 4.2 Subclass Euechinoidea Bronn, 1860

Apical system: Genital plates pointed, hardly extending into interambulacra; ocular plates usually widely insert; periproct large and without a distinct ring of periproctal plates. Ambulacra: Pore zones very narrow, pore pairs almost as a straight line, toward the peristome in arcs of three; primary tubercles small, only present halfway toward apical disc; pore zones not widened at the peristomial edge; regular series of one primary tubercle per plate. Interambulacra: Primary tubercles on aboral side almost totally lacking, only a few scattered small ones; naked bifurcating median areas not well-defined and rather inconspicuous; primary tubercles on oral side in the proximal part abruptly and strongly reduced, distally arranged in short vertical series, with only the outer row continuing just above the ambitus. Peristome: Buccal notches broad and rounded, ambulacral edge also indented. Spines: Verticillate, axial cavity without any meshwork. Color: Test and spines uniformly grayish brown. Pattern of iridophores: Spotted blue lights on interambulacra; a single spot below each genital pore. Distinct markings visible on naked test. Distribution: Philippines. About 200 to 400 m. Eremopyga denudata Meijere, 1904 (Fig. 4.107 C–E) Test: Large, low, and more or less flexible; distinctly sunken both at the apical side and toward the peristome; maximum diameter may reach about 100 mm. Apical system: Genital plates pointed; ocular plates usually widely insert; periproct large and without a distinct ring of periproctal plates.

A

Ambulacra: Narrow, pore pairs in almost vertical arcs of three, pore zones not widened at the peristomial edge; one primary tubercle per plate, arranged in regular rows, adapically lacking. Interambulacra: Naked bifurcating areas conspicuously sunken; on oral side, regular series of larger tubercles decreasing in size and number toward the peristome; only the adradial primary series continues aborally to the apical system. Peristome: Sunken; broad, rounded buccal notches; ambulacral edge indented. Spines: Verticillate, axial cavity without any meshwork. Color: In the main, uniformly brownish purple. The denuded test is pale green. Pattern of iridiphores: The blue lights in the interambulacra are elongated; in larger specimens, united into a broad band; on each genital plate, one, sometimes two, spots are present. The markings on the naked test are very distinct. Distribution: Known from the Philippines through the Malayan region to northern Australia, 70 to 275 m. Genus Goniodiadema Mortensen, 1939 The genus differs from the other diadematids by the strong­ly pentagonal test. There is one species. Goniodiadema mauritiensis Mortensen, 1939 (Fig. 4.108) Test: Large, strongly pentagonal, the angles formed by the interambulacra; slightly flexible, flat on the oral side, but not sunken toward the peristome, aborally lowly hemispherical; maximum diameter more than 100 mm.

B

Fig. 4.108: Goniodiadema mauritiensis. (A) Aboral side, partly with spines, buffered, diameter 115 mm; Mauritius. ZMUC ECH 39. (B) Oral side. The test is strongly pentagonal.



Apical system: Hemicyclic, oculars I and V insert, the others widely exsert; periproct large and without plates. Ambulacra: Very narrow, no adoral widening, pore pairs in arcs of three throughout, aborally in straight lines; on oral side, more irregular and widely spaced near the peristome; each plate with a primary tubercle. Interambulacra: Upper side in the main naked, set with some scattered secondary tubercles; at the ambitus up to four large tubercles per plate, reaching just onto the upper side; on the oral side, the primaries form regular series decreasing in size toward the peristome. Spines: Hollow, although robust, verticillate. Color: Test in life cream, faintly reddish on aboral side; denuded test tinted green, spines pale green with red brown distally. Pattern of iridophores: Aboral median areas with iridescent blue spots. Distribution: Mortensen (1939) reported the species only from Mauritius, Indian Ocean. Depth 235 m. Genus Lissodiadema Mortensen, 1903 Mortensen (1940) found the genera Lissodiadema (L. lorioli) and Leptodiadema (L. purpureum) very closely related but clearly differentiated from the other diadematid genera. They are distinguished from those in having smooth spines, not verticillate ones. The tubercles in Lissodiadema are non-crenulate; in Leptodiadema, only slightly crenulate. Smith & Coppard (2005) synonymized the two genera remaining a single species. Lissodiadema lorioli Mortensen, 1903 Test: Thin and slightly flexible; low, flattened above and below, apical system hardly sunken, ambulacra not inflated. Apical system: Distinctly sunken; ocular plates broadly insert, except plate O II in young specimens exsert, in adult narrowly insert, all plates naked; gonopores surrounded by a rim and with long papillae; periproct with distinct anal cone. Ambulacra: Broad, slightly widened on the upper side; on aboral side, pore pairs in a straight series along the outer suture, moving toward the center of the plates at the ambitus, slightly crowded at the peristomial edge; aboral interporiferous zone densely tuberculated with the tendency to form up to four vertical rows and becoming rather rudimentary toward the apical disc; on oral side, two series of tubercles of different size, while on the outer space of the plates there is an additional row of tubercles. Interambulacra: Low plates with up to three larger tubercles ambitally, between them one or two smaller tubercles that usually lie one above the other; broad naked zone adapically, narrowing along the median line; on oral side,

4.2.4 Order Micropygoida Kroh & Smith, 2010 

 187

series of tubercles converging, leaving distinct naked areas. Peristome: Strongly raised; membrane naked except very small buccal plates, deep and broad notches. Spines: Very long and thin, with fine longitudinal ridges, not verticillate. Color: The test in life is bright purple, especially the apical plates with the madreporite and the buccal membrane. The cleaned test is greenish white. The long spines are of a wonderful golden yellow. Distribution: The species is known from Indonesia and from Japan to the central Pacific islands in deeper water.

4.2.4 Order Micropygoida Kroh & Smith, 2010 4.2.4.1 Family Micropygidae Mortensen, 1904 Genus Micropyga A. Agassiz, 1879 The single genus in the family differs from all other echinoids in having two series of pore pairs in each ambulacrum: the pore pairs of the inner series are set with normal tube feet, the single pore of the outer series bears podia, which are transformed into umbrella-like structures with long, flexible stalks being confined to the aboral side and the ambitus. Test: Large and low. Apical system: Monocyclic, all ocular plates broadly insert. Interambulacra: Two series of primary tubercles positioned nearly in the middle of the plates, adapically a naked median space; tubercles not crenulated. Peristome: Small and sunken, very conspicuous buccal notches. Primary spines: Hollow, finely thorny, but not verticillate; very brittle; secondary spines simple. Remark: Micropyga differs from Astropyga by the lack of the V-shaped naked areas in the aboral interambulacra and by the very distinct buccal notches. Two species belong to this genus: Micropyga tuberculata A. Agassiz, 1879. Indo-West Pacific. Micropyga violacea de Meijere, 1902. From East Africa to the Philippines. They differ in the ambulacra: in M. tuberculata, every second plate carries a primary tubercle, whereas in M. violaceum, each plate has one. Literature: Döderlein 1906. Micropyga tuberculata A. Agassiz, 1879 (Fig. 4.109) Test: Large, aboral side lowly hemispherical, oral side flat, margin rounded; test may also be wheel-shaped; maximum diameter more than 110 mm.

188 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

E

Fig. 4.109: Micropyga tuberculata. (A) Aboral side with spines, diameter of test 82 mm; Kei Islands, Indonesia. ZMH. (B, C) The umbrellashaped tube feet are unique in the echinoids. (B) In open state with an upright stem. (C) Collapsed and with a crumpled stalk. The umbrella is supported by thin, calcareous rods, anchor-shaped spicules are embedded in the stem. Scale: 1 mm (Döderlein 1906). (D) Aboral side of test, diameter 115 mm; Cebu, Philippines. There are no naked bifurcating areas as in Astropyga radiata. (E) Oral side. The buccal notches are extremely deep and sharp.

Apical system: Periproct covered by numerous polygonal plates densely set with tubercles. Ambulacra: Three alternating pore pairs per plate forming two vertical series, the inner row with normal tube feet, the outer with umbrella-like podia; primary tubercles on each second plate.

Interambulacra: Two series of primary tubercles in the middle of the plates, outer part of plates with more or less regular series of secondaries, inner part with rows of small secondaries only around the ambitus and on the oral side, adapically decreasing in size, leaving a naked median space. Peristome: Deeply incised, sharp buccal notches.

4.2.5 Order Pedinoida Mortensen, 1939 



A

 189

B

Fig. 4.110: Micropyga violacea. (A) Aboral side of test, diameter 81 mm; Philippines. ZMUC. (B) Oral side: the buccal notches are not as deep as in Micropyga tuberculata, but relatively broad and rounded.

Spines: Primary spines hollow and very brittle; oral primaries club-shaped or more or less trumpet-shaped. Color: The upper surface is bright purple with lighter stripes radiating along the median areas and darker bands along the pore zones. The primary spines are white or somewhat reddish. Distribution: Micropyga tuberculata is recorded from East Africa through the Malayan Archipelago and the Philippines to New Britain and northeast Australia. Bathymetric range 150 to 1,340 m. Micropyga violacea de Meijere, 1902 (Fig. 4.110) Test: Slightly domed with rounded margin; maximum diameter about 90 mm. Apical system: Large ocular plates, tuberculated only on the inner part and slightly elevated distally. Ambulacra: Broad band of pore pairs, three pairs per plate, the middle component of each plate having alternately the pore in the inner or the outer series with its umbrella-shaped podia; each plate set with a primary tubercle; regular series of secondaries reaching halfway to the peristome and to the apex. Interambulacra: Regular series of primary tubercles, toward the ambitus up to 4 rows of secondaries. Peristome: Buccal notches shorter, but wider than in M. tuberculata. Distribution: Known in the Indo-West Pacific from East Africa through the Malayan region to the Philippines, at a depth 625 to 925 m.

4.2.5 Order Pedinoida Mortensen, 1939 Members of this order date back to the Upper Triassic of Peru (Smith 1994). In Europe, they were rather common in Early Jurassic shallow water settings, but became rare toward the Early Cretaceous. In the Eocene, a single genus, Leiopedina Cotteau, 1866, still occurs, and in the Miocene, there is only one record from Patagonia. The pedinoids of today are deep sea forms, comprised in one genus, Caenopedina A. Agassiz, 1869, with numerous species. The extant pedinoids differ from the other “diademataceans” by their dicyclic apical system and by their solid primary spines. The tubercles are perforated and non-crenulated. Literature: Mortensen 1940; Pawson 1964; McKnight 1968; Smith 1994; Anderson 2009; Tracey et al. 2011.

4.2.5.1 Family Pedinidae Pomel, 1883 This family includes many fossil genera. Only one genus survives today. Genus Caenopedina A. Agassiz, 1869 The genus is characterized by a dicyclic apical system with a compact, slightly raised madreporite and tiny uniform periproctal plates. The interambulacral primary tubercles almost cover the entire height of the plates.

190 

 4.2 Subclass Euechinoidea Bronn, 1860

Test: Low, upper side flattened; usually of moderate size just reaching about 40 mm (exception: Caenopedina porphyrogigas). Apical system: Large with plates arranged in a dicyclic circle; large subcircular periproct covered by small uniform platelets; madreporite not enlarged; pores confined to a small slightly elevated area; distinct sexual dimorphism in the shape of the gonopores: in males, more or less slit-like at the outer edge of the genital plates, sometimes continuing as long grooves into interambulacra: in females round, lying subcentrally on the genital plates; in C. otagoensis, they form a multiple row. Ambulacra: Compound plating in triads, each element reaching over the whole width and set with an obliquely positioned pore pair; pore zones widened adorally; one large primary tubercle per compound plate much smaller than in interambulacra forming regular series. Interambulacra: Much broader than ambulacra; regular series of one large primary tubercle per plate, adorally decreasing in size; areoles large and usually confluent, surrounded by more or less heterogeneous tuberculation; mamelons small; all primary and secondary tubercles perforated. Peristome: Rounded buccal notches distinct; pairs of buccal plates close together, but distant from the next pair; membrane otherwise covered in small platelets mostly in ambulacral position. Spines: Primaries solid, mostly long and slender; rather smooth compared to the verticillate spines of diadematoids, sometimes slightly serrated or with tiny thorns; adorally decreasing in size; secondary spines much smaller and hollow. The genus includes at least 13 species, which are very similar in test plate ornamentation. They are distinguished – in addition to the shape of the pedicellariae – mainly by the arrangement of the tubercles on the apical plates and by the color of their spines and apical plates. But as (local) variations and intermediate forms seem to occur, identification on species level is sometimes difficult. Pawson (1964) felt some “species” were not well defined and suggested that some of them could be reduced to subspecific level or should be joined into polytypic groups. Caenopedina alanbakeri Rowe, 1989. Norfolk Islands, Tasman Sea. Caenopedina annulata Mortensen, 1940. Malayan Archipelago. Caenopedina capensis H. L. Clark, 1923. South Africa. Caenopedina cubensis A. Agassiz, 1869. Caribbean. Caenopedina depressa Koehler, 1927. Maldives; insufficiently known. Caenopedina diomedeae Mortensen, 1939. East Pacific, Gulf of Panama.

Caenopedina hawaiiensis H. L. Clark, 1912. Hawaii. Caenopedina indica (de Meijere, 1903). Philippines. Caenopedina mirabilis (Döderlein, 1885). Japan to the east coast of Australia. Caenopedina novaezealandiae Pawson, 1964. New Zealand and east coast of Australia. Caenopedina otagoensis McKnight, 1967. From Macquarie Ridge along the east coast of New Zealand to ­Kermadec Ridge and west of Tasmania. Caenopedina porphyrogigas Anderson, 2009. New Zealand and southeast Australia. Caenopedina pulchella (A. Agassiz & H. L. Clark, 1907). Hawaii and Japan, northern New Zealand. Caenopedina superba H. L. Clark, 1925, Indian Ocean. Caenopedina alanbakeri Rowe, 1989 Apical system: Plates rather high; periproct small; the slit-like genital pores of the males positioned at outer edge of genital plate continue as depressed lines downward on the interambulacral plates, not leading along the median suture; tubercles scattered on the genital plates, the distal part being naked. Spines: Short and relatively stout. Color: Apical plates pink; primary spines not banded, deeper pink at the base, becoming paler pink to lime color toward their tips. Distribution: The holotype was found E of Norfolk Island at a depth of about 575 m. Caenopedina annulata Mortensen, 1940 (Fig. 4.111) Diameter up to 31 mm. Apical system: Two clusters of tubercles on genital plates, one along the inner edge with a ring of large tubercles and one with smaller tubercles scattered at the outer border; the center is naked and sculptured; ocular plates well tuberculated; periproctal plates very small, almost undistinguishable. Peristome: Except for the buccal plates, the peristomial plates are mainly confined to the ambulacral position. Primary spines: Slender and long, up to 2.5 times the horizontal diameter of test. Color: In life, the test is dark, well-cleaned tests have a greenish brown tinge in the large interambulacral areoles, especially aborally; the apical system is brown with a darker band along the naked areas in the genital plates; the primary spines are conspicuously banded by well-defined, narrow bands in reddish brown and greenish white. The secondary tubercles are green. Distribution: This species is recorded throughout the Philippines and the Malayan Archipelago to New Caledonia. Bathymetric range 145 to 245 m.



4.2.5 Order Pedinoida Mortensen, 1939 

 191

Interambulacra: Primary tubercles small, leaving a broad median space with a distinct alternating row of secondaries. Primary spines: Not widened. Color: Spines always unbanded in white; test varying from almost white to almost purple and covered with small purple dots. Distribution: Pacific coast of Panama.

Fig. 4.111: Caenopedina annulata. Diameter of test 22 mm; Kei Island, Indonesia. ZMUC ECH 78. Close-up of the apical system: a conspicuous ring of larger tubercles surrounds the periproctal edge, clusters of smaller tubercles cover the distal part of the genital plates and the entire oculars. The center of the genital plates is naked, marked by dark brown areas, which often form a continuous ring. Near the gonopores, there are some scattered small black spots.

Caenopedina capensis H. L. Clark, 1923 Ambulacra: Pore pairs in almost straight rows. Color: All apical plates bright purplish; primary spines distally more or less purplish, base sometimes light reddish. Distribution: South Africa. Caenopedina cubensis A. Agassiz, 1869 (Fig. 4.112 A) Test: Flattened, diameter up to 33 mm. Apical system: Tubercles scattered over the genital plates; inner periproctal plates with small tubercles. Primary spines: Long and slender, distally widened. Color: The test and all spines are whitish, the apical plates pale gray. Distribution: Found in the West Indies and northward along the east coast of the USA to Nantucket; off the Azores and Canaries at depths of 250 to about 1,200 m. Caenopedina depressa Koehler, 1927. Maldives; insufficiently known (Mortensen 1940). Caenopedina diomedeae Mortensen, 1939 (Fig. 4.113 A, B) Test: Flattened above; diameter of test may reach 26 mm. Apical system: Ocular plates with rounded borders; tubercles on genital plates confined to periproctal edge. Ambulacra: Pore pairs in distinct arcs of three; compared to other species, rather few plates, 12–13 against 16–17 in C. indica (similar to C. cubensis with 14 plates).

Caenopedina hawaiiensis H. L. Clark, 1912 (Fig. 4.112 B–D) Test: Flattened; diameter may reach 37 mm. Apical plates: With only few scattered tubercles, mostly concentrated along the periproctal edge; gonopores in females conspicuous and positioned in the center of the genital plate, in males, slit-like situated at the very distal point of the plate, continuing in a fine depressed line running down almost to the ambitus; periproct covered by numerous, round plates. Ambulacra: Pore pairs in steep vertical series, primary tubercles separated by few miliaries. Interambulacra: With large, broadly coalescent tubercles. Color: The test is dark purplish, fading toward the underside and deepest on the apical plates; the primary spines are red brown and merge distally into yellow green, showing no bands at all. Distribution: The species is endemic to the Hawaiian Islands. Bathymetric range 460 to 1,945 m. Caenopedina indica de Meijere, 1903 (Fig. 4.113 C) The diameter may reach 30 mm. Test: Sides subvertical, large specimens relatively higher than smaller ones. Apical system: Larger tubercles only along the inner edge of the genital plates, distal parts naked; gonopores in males continuing in a more or less short furrow; periproctal plates too numerous to be distinguishable, not carrying tubercles. Color: The upper side of the test is somewhat rosy, especially the apical plates, sometimes more red brown. The primary spines are red brown with 1–3 ill-defined bands on the distal part; sometimes, there occurs a greenish band, and in rare cases, the spines appear to be uniformly pale red. Distribution: This species lives in the Malayan and Philippine region at depths of 245 to 985 m. Caenopedina mirabilis Döderlein, 1885 (Fig. 4.89 D, 4.113 D) Apical system: Larger tubercles scattered over the plates; periproctal plates small but well-recognizable, polygonal; larger than in C. annulata, and C. indica.

192 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

Fig. 4.112: (A) Caenopedina cubensis. Aboral side with some remaining spines, diameter of test 33 mm; off the Canaries at a depth of 1,092 m. ZMUC. (B–D) Caenopedina hawaiiensis. (B) Aboral side of a male, diameter 29 mm; Hawaiian Islands. ZMUC. Only a few tubercles are scattered over the apical plates, for the most part concentrated along the periproctal edge. (C) Oral side: the broad buccal notches are rounded. (D) Side view: the slit-like gonopores of the male continue in a narrow line downward below the ambitus, often not following the vertical suture (see arrow).

Ambulacra: in width 40–50 % of interambulacra. Interambulacra: Secondary tubercles at the outer sides and along the midline well-developed. Color: The primary spines are banded with broad, not sharply defined bands in reddish brown and white; the secondary spines are whitish. The bands may be so faint as to appear uniformly red brown. The denuded test shows a gray to purple tint. The apical plates may be red brown to distinctly purple.

Distribution: This species occurs from Japan (Sagami Bay) through the Philippines and the Malayan Archipelago to the southeast coast of Australia. Bathymetric range 80 to 540 m. Caenopedina novaezelandiae Pawson, 1964 Test: Round, flattened, holotype with a diameter of 30 mm.

4.2.5 Order Pedinoida Mortensen, 1939 



A

 193

B

C

D

Fig. 4.113: (A, B) Caenopedina diomedeae. Part of apical disc of male: the gonopores are slit-like. (B) Ambulacral plates. Scale: 4 mm (Mortensen 1940). (C) Caenopedina indica. Aboral side with some spines, diameter 25 mm; off eastern Taiwan. The periproctal plates are very numerous and very tiny. (D) Caenopedina mirabilis. Aboral side of test, female partly with spines, diameter of test 18 mm; Sagami Bay, Japan. ZMUC. The gonopores are round. Numerous heterogeneous tubercles are scattered on the outer parts of the apical plates.

Apical system: With rather low genital plates, periproct distinctly pentagonal with eccentric opening; tubercles on genital plates more or less scattered. Ambulacra: Pore pairs small. Interambulacra: Large and confluent areoles, secondary tubercles only along the median line and the outer edge.

Spines: Primaries in length up to 3 times the test diameter, secondaries long, all spines set with numerous spinelets. Color: Primary spines green becoming lighter green distally with broad more or less well-defined bands in greenish, white, and pale red brown in no particular order; secondary spines white with faint tinge of green. Denuded test white with brownish green tint at the apical system.

194 

 4.2 Subclass Euechinoidea Bronn, 1860

Distribution: The species is known from the North Island of New Zealand (Auckland) to the Three Kings Ridge and in the northern Tasman Sea at 285 to 600 m. Caenopedina otagoensis McKnight, 1968 Test diameter up to 40 mm. Apical system: Ocular plates exsert with three small tubercles; genital plates with 5 to 7 larger tubercles along the periproctal edge and some smaller ones; genital pores in males slit-like continuing onto the interambulacral plates, in females, there are 3 to 6 pores arranged mostly in a series; periproct with numerous small plates, some of which carry small tubercles/spines. Primary spines: In length, up to 2 times the test diameter; longitudinally striated and with very fine serrations. Globiferous pedicellariae: With black poison glands. Color: Test and spines red brown, the apical system purple black; primary spines not banded, may be lighter toward the distal end. Distribution: The species is known around New Zealand from the Macquarie Ridge to the southern Kermadec Ridge and west of Tasmania. Bathymetric range 1,200 to 2,182 m. Caenopedina porphyrogigas Anderson, 2009 (Fig. 4.114) Test: Very large, diameter may reach 102  mm; rate of height to diameter strongly varying from 43 % to 77 %; upper side slightly flattened, oral side slightly concave.

A

Apical system: Dicyclic, genital pores appear to be equal in females and males (no specimens with slit-like gonopores are found); all plates evenly covered by small tubercles and granules but leaving naked margins; madreporite distinct, slightly raised. Ambulacra: Plates almost as high as wide, compounded in diadematoid style; large central primary tubercles, forming regular series from apical disc to peristome, surrounded by small tubercles of various size; pore pairs in steep arcs of three, obliquely positioned, on oral side larger, the arcs in zigzag lines with widened pore zones. Interambulacra: Consisting of 27–28 plates per column, individual plate short and wide, distinctly bent; large primary tubercles forming regular rows, scarcely decreasing in size toward the apical disc; areoles frequently not confluent; interradially second series of tubercles of less than half the size of primaries; remainder of plate densely covered by much smaller tubercles of various size. Peristome: Small, buccal notches shallow. Primary spines: Very finely striated, milled ring symmetrical, not oblique (compare Caenopedina novaezealandiae). Globiferous pedicellariae absent. Color: The test of living and preserved specimens is brown purple, deepest around the apical system, and on the oral side, the spines are a bright brown. Dried and cleaned specimens are cream colored with a pink to

B

Fig. 4.114: Caenopedina porphyrogigas. (A) Aboral side with spines, diameter of test about 80 mm; Chatham Rise, New Zealand. The primary tubercles in the interambulacra form very conspicuous regular rows scarcely decreasing in size toward the apical disc. (B) Oral side: the tube feet are extended (photos by Owen F. Anderson, NIWA, Wellington, New Zealand).



mauve tint along the sutures, the pore zones, and around the apical disc. Distribution: This species is found at the South Tasman Rise and in the waters around New Zealand from the Macquarie Ridge to the West Norfolk Ridge, the Colville Ridge, and the northern Chatham Rise. Bathymetric range 219 to 1,450 m. Caenopedina pulchella Agassiz & Clark, 1907 Test: Diameter mostly less than 30 mm. Apical system: Only a few tubercles scattered on genital plates, median space sculptured; only 20–30 periproctal plates. Primary spines: Relatively short and stout. Color: Apical plates deep brownish rose; primary spines light green at base, then dull rose to reddish and distally almost whitish. Distribution: Hawaii and Japan, northern New Zealand. Depth 370 to 530 m. Caenopedina superba H. L. Clark, 1925 Apical system: A few tubercles confined to the inner edge of the genital plates; numerous periproctal plates. Primary spines: Rather short and stout. Color: Apical plates reddish white; secondary spines dull red or greenish; primary spines white becoming green distally or basally green with dull red ill-defined bands. Distribution: Indian Ocean.

Carinacea Kroh & Smith, 2010 The newly established taxon Carinacea Kroh & Smith, 2010 consists of the Superorders Calycina and Echinacea, which share the presence of keeled teeth (Fig. 2.10).

Superorder Calycina Gregory, 1900 4.2.6 Order Salenioida Delage & Hérouard, 1903 The Salenioida are characterized by keeled teeth and a large apical system with incorporated angular suranal plate. The primary tubercles in the interambulacra are imperforate and partly crenulate. The predominant part of the genera is extinct. A single family with only two genera survived today.

4.2.6 Order Salenioida Delage & Hérouard, 1903 

 195

4.2.6.1 Family Saleniidae L. Agassiz, 1838 The most typical characteristic of the saleniid genera is the large suranal plate within a ring of genital and ocular plates. Consequently, the periproct is offset from the usual anterior-posterior axis toward ocular plate I. The family consists of two extant genera: Salenocidaris A. Agassiz, 1869. Seven species. Bathysalenia Pomel, 1883. Six species. They differ in the following characteristics: In Salenocidaris, the ambulacral plates are simple being perforated by a single pore pair except near the peristome, where there are 2 pore pairs per plate. Each plate is set by a tubercle. In Bathysalenia, the compound ambulacral plates have 2 pore pairs throughout (except in the uppermost plates in some species), each carrying 1 tubercle. This is the more advanced condition. (Fig. 4.115) In Salenocidaris, the apical disc is covered by numerous more or less uniform pustules. In contrast to this, the ocular plates and/or the distal part of the genital plates of Bathysalenia have developed more or less V-shaped prominent structures, which are often set off in color. Literature: A. Agassiz 1904; A. Agassiz & H. L. Clark 1907, 1908; Mortensen 1904, 1935; Zullo et al. 1964; Shigei 1986; Mironov 2006, 2009; Kroh & Smith 2010. Genus Salenocidaris A. Agassiz, 1869 Test: Of small size. Apical system: Relatively very large, continuing flush with the test; plates covered in small, rough papillae, with and without pits in sutures; periproct offset to ocular plate I; distinct suranal plate smaller than periproct. Ambulacra: Simple plates with a single pore pair except near the peristome, single tubercle per plate. Interambulacra: Tubercles imperforate and crenulate. Peristome: Buccal notches obsolete. Spines: More or less long and slender, thorny. Color: Whitish with more or less intensive purplish on apical plates and/or secondary spines. Nine species are included: Salenocidaris brachygnata Mortensen, 1934. Kermadec Islands. Salenocidaris crassispina A. Agassiz & H. L. Clark, 1907 Salenocidaris hastigera A. Agassiz, 1879. Malayan region to Tasman Sea, North Cape of Australia, New Zealand. Salenocidaris incrassata Mortensen, 1934. Celebes, Indonesia. Salenocidaris miliaris A. Agassiz, 1869. Cocos Island, Galapagos Islands, Hawaii, perhaps Japan (Shigei 1986 did not include this species in his checklist for Japan).

196 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

Fig. 4.115: Main characteristics of Saleniids. (A) Apical disc of Salenocidaris varispina: the pustules on the periproctal and apical plates are more or less uniform. (B) Bathysalenia cincta: the pustules on periproctal and genital plates are low. On the distal part of the disc prominent V-shaped structures are developed. Scale: 2 mm (suranal plates are shaded) (Mortensen 1935). (C) Ambulacral plates Salenocidaris miliaris: simple plates (one shaded). Only near the peristome (below) occur a few plates with 2 pore pairs (lower shaded plate). (D) Bathysalenia goesiana: in this more advanced genus, the compound plates are perforated by 2 pore pairs throughout (sample plates shaded) carrying a tubercle. A. Agassiz 1904: diameter of test: Salenocidaris miliaris 13 mm, Bathysalenia goesiana ( = S. pattersoni) 10 mm.

Salenocidaris nudispina Markov, 1988. South Pacific, on seamounts. Salenocidaris pacifica Döderlein, 1885. Japan. Salenocidaris profundi Duncan, 1877. Atlantic, West Indies to the Bay of Biscay, from southwest of Iceland to Tristan da Cunha. Salenocidaris varispina A. Agassiz, 1869. Atlantic, West Indies to Brazil, Azores, Canaries, Bay of Biscay. The species are rather similar and difficult to distinguish. Salenocidaris brachygnata Mortensen, 1934 Known only from a young specimen of 7 mm being differenciated from the other Pacific species by the pedicellariae. Occurrence: Kermadec Islands at a depth of 1,080 m. Salenocidaris crassispina A. Agassiz & H. L. Clark, 1907 Known only from a young specimen. Spines: Smooth, verticillate and with a curved point. Occurrence: Hawaii. Depth 265 to 355 m. Salenocidaris hastigera A. Agassiz, 1879 Test: Diameter up to 17 mm. Apical system: Ocular plate I exsert. Secondary spines: Short, thickened. Distribution: Malayan region to Tasman Sea, North Cape of Australia, New Zealand, 370 to 2,565 m. Salenocidaris incrassata Mortensen, 1934 Test: Diameter up to 12 mm. Apical system: Ocular plate I broadly insert, no rim around the periproct.

Interambulacra: Areoles rather small, not confluent as in the other species; median area rather broad, covered with coarse miliary tubercles. Spines: Primaries thin, thorns not in distinct whorls; secondaries short and unwieldy. Distribution: Celebes, Indonesia, about 1,400 m. Salenocidaris miliaris A. Agassiz, 1869 (Fig. 4.115 C, 4.116 A) Test: High, apical system continuing flush with the test, thus almost spherical. Apical system: Numerous slender papillae, distinct genital papillae. Ambulacra: Pores rather large, especially on the upper side. Interambulacra: Adorally, 3–4 small primary tubercles; above the ambitus, 2–3 larger tubercles, abrupt transition. Spines: Primary spines up to 5 times the diameter, some of them slightly curved, shaft ridged with small thorns, secondary spines broad and flat, almost fan-shaped. Color: Test and secondary spines dark purple, papillae of apex light claret in life specimens, fading out in preserved specimens to grayish purple, primary spines brilliant white. Distribution: From the Hawaiian Islands and Japan to the Galapagos Islands and Panama, 1,200 to 3,000 m. Salenocidaris nudispina Markov, 1988 Occurring in the Southeast Pacific on seamounts and knolls. Salenocidaris pacifica Döderlein, 1885 (Fig. 4.115 B) Test: Small, rather high and subconical. Apical system: Ocular plate I broadly insert, edge to periproct raised.

4.2.6 Order Salenioida Delage & Hérouard, 1903  



A

C

 197

B

D

Fig. 4.116: (A) Salenocidaris miliaris. Aboral side with some remaining spines, test diameter 10 mm; Galapagos Islands. ZMUC. (B) Salenocidaris pacifica. Side view with spines, diameter of test 7 mm; Japan (sketch after a photo of H. van Noordenburg). (C) Salenocidaris profundi. Side view of test with a few spines, diameter of test 14 mm; southwest of Iceland. ZMUC. (D) Salenocidaris varispina. Aboral side with a few spines, diameter of test 9 mm; Brazil. ZMUC. The papillae on the apical disc are arranged in concentric rows around the gonopores.

Ambulacra: Pore pairs small. Interambulacra: Median space rather broad, no tubercles between scrobicular rings. Spines: Primaries slender, thorny, and verticillate, length not much more than twice the diameter of test; secondary spines rather thick and strongly curved; periproctal spines thick and flattened.

Color: Test and spines white, secondary spines covered with purplish granules. Distribution: Japan. Depth about 200 m. Salenocidaris profundi Duncan, 1877 (Fig. 4.115 C) Maximum size 15 mm. Apical system: Ocular plate I in adults insert.

198 

 4.2 Subclass Euechinoidea Bronn, 1860

Spines: Primaries about 5 times the diameter, curved downward; primaries on oral side increasing gradually in size toward the large ambital spines; secondaries like slender scales, not curved. Color: Periproct only very faintly purplish, test otherwise white. Distribution: Atlantic from the West Indies to the Bay of Biscay, from southwest of Iceland to Tristan da Cunha. Bathymetric range ~1,700 to 3,120 m. Salenocidaris varispina A. Agassiz, 1869 (Fig. 4.115 A, 4.116 D) Test: Rather low, oral side flattened, in diameter hardly exceeding 12 mm. Apical system: Ocular I in adult insert, periproctal spines thick and short. Spines: Primaries about 3 times the diameter, distinctly curved downward; secondaries strongly curved. Color: Periproct and gonopores dark purple to claret, test otherwise white. Distribution: Known from the West Indies to Brazil and from the Azores and the Bay of Biscay to Ascension Island, South Atlantic. Bathymetric range at least 650 to 2,160 m. Remark: The two Atlantic species, S. profundi and S. varispina, differ in the following characteristics: S. profundi has much narrower median interambulacral areas, more thorny spines, and more slender secondary and periproctal spines. In S. varispina, the secondary spines are broader, scale-like, and strongly curved. Genus Bathysalenia Pomel, 1883 This genus, more advanced than Salenocidaris, is characterized by a slightly raised apical disc with pustular ornamentation. Many species are known since the Cretaceous, only six species survive.

Bathysalenia cincta A. Agassiz & H. L. Clark, 1907. Japanese and Malayan Seas. Bathysalenia goesiana Lovén, 1874. Caribbean. Bathysalenia phoinissa A. Agassiz & H. L. Clark, 1906. South Africa. Bathysalenia scrippsae Zullo et al., 1964. Off Chile. Bathysalenia sculpta Koehler, 1927. Indian Ocean, Andaman Islands. Bathysalenia unicolor Mortensen, 1934. Japanese and Malayan Seas. Test: Small, less than 15 mm in diameter; low hemispherical, apical disc flat, oral side also flattened. Apical system: Very large, with dense, low granulation; distinct suranal plate, periproct offset to the posterior right side (ocular plate I); ocular pores lie distally below horseshoe-shaped prominent structures; gonopores concealed under enlarged papillae at the distal edge of the genital plates, only a few madreporic pores. Ambulacra: Compound plates with 1 tubercle to 2 pore pairs, much smaller than interambulacral tubercles, pores somewhat crowded at the peristomial edge. Interambulacra: Primary tubercles large and crenulated, some small secondary tubercles. Peristome: Smaller than apical disc; buccal notches inconspicuous. Spines: Primary spines very long and slender, finely ridged, and slightly verticillate; ambulacral spines short, conspicuously broad and flattened. Remarks: The naked tests are difficult to distinguish. The differences rely mostly on the color of the primary spines and the position of the ocular plate I. Bathysalenia cincta A. Agassiz & H. L. Clark, 1907 (Fig. 4.115 B, 4.117, 4.118 A, B) Test: Diameter hardly reaching 15 mm.

Fig. 4.117: Bathysalenia cincta. Aboral side with spines, diameter of test 9 mm, longest spine 45 mm; Sagami Bay, Japan. ZMUC. The long primary spines are brightly banded, the color being paler on the oral side.

4.2.6 Order Salenioida Delage & Hérouard, 1903  



A

 199

B

C

D

Fig. 4.118: (A, B) Bathysalenia cincta. (A) Aboral side of test. Diameter 8 mm; Cebu, Philippines. The large suranal plate is shifted toward interambulacrum 3, the position of the periproct (lost) toward ocular plate I. (B) Close-up of aboral side with spines, diameter of test 9 mm; Sagami Bay, Japan. ZMUC. The periproct is offset toward ocular plate I. The short secondary spines are broad and flattened. (C, D) Bathysalenia goesiana. (C) Aboral side with spines, diameter of test 11 mm, longest spine 44 mm; West Indies. ZMUC. There are only a few red bands on the primary spines. (D) Close-up of aboral side: the apical plates are strongly set with granules.

Apical system: Ocular plate I insert. Primary spines: Slightly curved, shaft smooth with not very conspicuous, verticillate thorns. Color: The test is grayish purple with light green secondary spines and apical system. There is a conspicious dark arch on the ocular plates, best seen on the cleaned test. The primary spines are banded in red and white. The naked test is tinted in green. Distribution: This species is found in the West Pacific from Sagami Bay, Japan, to the Malayan Archipelago at depths of 170 to 520 m.

Bathysalenia goesiana Lovén, 1874 (Fig. 4.115 D, 4.118 C, D) Test: Up to 17 mm in diameter (Agassiz 1906). Apical system: Ocular plate I broadly insert. Primary spines: Not verticillate, but smooth and with some irregular thorns, tip straight. Color: Test and secondary spines light brown; fine and constant dark line leading from the apical system down the midline of each ambulacral and interambulacral area and bordering the apical plates; primary spines greenish with one to three brilliant red bands.

200 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

C

E

Fig. 4.119: (A, B) Bathysalenia phoinissa. (A) Apical system: there are only a few madrepores at the outer edge of the genital plate 2. (B) Test with spines, aboral side, diameter of test 11 mm; Agulhas Bank, South Africa. MfN Berlin. (C) Bathysalenia sculpta. Apical disc: the structures on the plates are very distinct. (D, E) Bathysalenia unicolor. (D) Apical disc: the angles on the ocular plates are small. (E) Aboral side with spines, diameter of test 12 mm; Sagami Bay, Japan. ZMUC ECH 339. The long primary spines are not banded as in the other species of Bathysalenia. Scale: (A, C, D) 2 mm (Mortensen 1935).

Distribution: West Indies from off Havana to off Barbados, 90–540 m. Bathysalenia phoinissa A. Agassiz & H. L. Clark, 1908 (Fig. 4.119 A, B) Test: Diameter up to 11 mm. Apical system: Low granules; ocular plate I exsert. Primary spines: Long and slender with distinct low granules. Color: Primary spines banded in red and light greenish, base slightly swollen. Distribution: Recorded from off South Africa only on the Agulhas Bank. Depth 102 m.

Bathysalenia scrippsae Zullo et al., 1964 Test: Maximum diameter of 9 mm. Apical system: Suranal plate angular; periproct bordered by elevated rim, genital and ocular pores not visible from above; madreporic pores not observable from exterior; all plates highly ornamented by distinct irregular ridges and knobs. Ambulacra: Straight and narrow; plates with 2 pore pairs except for a few simple plates interposed between the compound ones. Interambulacra: 5–6 plates per column. Primary spines: Up to 24 mm, slender, straight, longitudinally striated; largest at ambitus; oral primaries short, spearshaped; ambulacral spines short, broad, and flattened.



4.2.7 Order Stomopneustoida Kroh & Smith, 2010 

 201

Color: Aborally, the test is orange red with a green tint, the oral side is white; apical sculpture yellow green, white, or reddish. The primary spines are banded in green and white, usually with additional bands of pink or orange red on either side of the white. The broad ambulacral spines are orange red to dark brown red with yellow green bases. Distribution: This species was found on a seamount located near the southwest end of the Nasca Ridge in the Southeast Pacific, about 1,200  km off the coast of Chile. Bathymetric range 200 to 350 m.

4.2.7 Order Stomopneustoida Kroh & Smith, 2010

Bathysalenia sculpta Koehler, 1927 (Fig. 4.119 C) Test: Diameter up to 8 mm. Apical system: Ocular plate I exsert. Primary spines: Approximately 6 reddish bands, broader than the white bands. Distribution: Off Andaman Island, 110 to 135 m.

Genus Glyptocidaris A. Agassiz, 1864 The genus is monospecific. It is characterized by crenulated tubercles.

Bathysalenia unicolor Mortensen, 1934 (Fig. 4.119 D, E) Test: Diameter about 12 mm. Apical system: Angles on the ocular plates shallow, ocular plate I exsert. Primary spines: About 4 times the test diameter; point distinctly curved; shaft verticillate. Color: Primary spines greenish white and not banded. Distribution: Known from Sagami Bay, Japan, to the Philippines and the Moluccan Sea. Bathymetric range 290 to 470 m.

Superorder Echinacea Claus, 1876 The Echinacea are characterized by keeled teeth (see Fig. 2.10 A) and a relatively small compact apical disc with a smooth periproctal rim. The superorder consists of three orders: Order Stomopneustoida Family Glyptocidaridae: mainly fossil genera, only one extant genus with a single species Family Stomopneustidae: one genus with a single species Order Arbacioida Family Arbaciidae with eight extant genera Order Camarodonta Infraorder Temnopleuridea with two families Infraorder Echinidea with five families Stomopneustoids and arbacioids share the shape of the jaw apparatus: the upper ends of the pyramids are separated (“stirodont”, term no longer in use). Contrarily, the camarodont acroechinoids differ in having the two hemipyramids connected by a bow, which gives the whole lantern greater strength.

The two families differ in the following features: Glyptocidaridae: Tubercles non-perforated and strongly crenulated. Stomopneustidae: Tubercles non-perforated and noncrenulated.

4.2.7.1 Family Glyptocidaridae Jensen, 1981

Glyptocidaris crenularis A. Agassiz, 1864 (Fig. 4.120 A, B) Test: Very low, hemispherical, oral side flattened; maximum diameter 80 mm. Apical system: Ocular plate I broadly insert, the others are widely exsert. Ambulacra: Two regular series of tubercles; 5 pore pairs per plate, almost uniserial. Interambulacra: Conspicuous bare median zones aborally; ambital tubercles largest. Peristome: Slightly sunken, buccal membrane densely plated. Spines: At ambitus, half the length of test diameter in adults, distally slightly flattened, much shorter on the aboral and oral side. Color: The denuded test is greenish olive on the aboral side with the median spaces in ambulacra and interambulacra whitish. The spines are a light grayish brown. Distribution: The species is restricted to northern Japan, from Hakodate to Mutsu Bay on the Pacific coast and in the Japan Sea southward to Sado Island. It lives at depths of 10 to 150 m.

4.2.7.2 Family Stomopneustidae Pomel, 1883 Genus Stomopneustes L. Agassiz, 1841 The genus is monospecific. Stomopneustes variolaris Lamarck, 1816 (Fig. 4.120 C–E) Test: Round to pentagonal; low hemispherical with thick margin, oral side flattened; test diameter may reach 110 mm. Apical system: Enlarged, naked madreporite, other plates tuberculated, ocular plates I and V broadly insert. Ambulacra: Broad; pore pairs in arcs of three, in large specimens appearing like a band of three irregular, vertical series; pore zones widening just below the ambitus,

202 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

E

D

Fig. 4.120: (A, B) Glyptocidaris crenularis. (A) Apical system. (B) Ambulacral plates. Scale: 5 mm (Mortensen 1935). (C–E) Stomopneustes variolaris. (C) Aboral side of test, diameter 71 mm; Ile de la Réunion. The interambulacral median suture is marked as a fine depressed line. (D) Oral side of test: the pore zones are conspicuously widened. The buccal notches are deeply indented, in smaller specimens they may be shallower. (E) Underwater, Oman: test and spines are uniformly black (photo by H. Moosleitner).

becoming broad phyllodes; near the apical system approaching each other, leaving only space for one row of very small tubercles; around the thick margin there are two alternating rows of large tubercles, almost as large as the interambulacral tubercles, on the oral side again becoming very small. Interambulacra: At the peristomial edge, very narrow; regular, vertical series of rather large tubercles, round the ambitus largest; median suture marked as an irregular, rounded zigzag line. Peristome: Rather small, about a third of the test diameter or less in larger specimens; deeply indented by rounded buccal notches; peristomial membrane almost naked. Spines: Solid, tapering to a blunt end; on the oral side, much smaller than on the upper side.

Color: In life, the test and the spines are totally black or dark purple. The bare test is dirty whitish, with a little green or purplish tinge. Biology: Stomopneustes variolaris lives in the littoral zone, mostly exposed to heavy waves on rocks or between coral rubbles, where the animals can attach themselves by their very numerous oral podia in the phyllodes. Often, the sea urchins hide in crevices in the coral. It may happen that one side of the test carries longer spines than the other. It is supposed that they sit with the shorter spines toward the wall, exposing the longer ones against possible predators. Distribution: This species is known from tropical and subtropical waters of the Indo-West Pacific from East Africa to the Samoa Islands, from Japan in the north to Australia and New Caledonia in the south. It is restricted to the tide zone.

4.2.8 Order Arbacioida Gregory, 1900 



4.2.8 Order Arbacioida Gregory, 1900 4.2.8.1 Family Arbaciidae Gray, 1855 The member of this family have developed in the apical system 4 or 5 large, equally sized anal plates covering the periproctal opening. The ambulacral plates are compound, consisting of a large central element bearing a tubercle, flanked by an upper and lower demi-plate. The median areas of the aboral interambulacra are more or less naked. The tubercles are non-perforate and non-crenulate. (Fig. 4.121) Eight Recent genera are included: Arbacia Gray, 1835. Five species. Arbaciella Mortensen, 1910. A single species. Coelopleurus L. Agassiz, 1840. Approximately ten species. Dialithocidaris A. Agassiz, 1898. A single species. Habrocidaris A. Agassiz & H. L. Clark, 1906. Two species.

A

B

 203

Podocidaris A. Agassiz, 1869. Three species. Pygmaeocidaris Döderlein, 1905. A single species. Tetrapygus L. Agassiz, 1841. A single species. Only in the small-sized arbaciids Arbaciella, Dialithocidaris, Habrocidaris, Podocidaris, and Pygmaeocidaris are the interambulacral primordial plates recognizable in adult specimens. In other echinoids, they are only visible in very young specimens, becoming concealed by the ensuing plates later in growth. Genus Arbacia Gray, 1835 Test: Lowly hemispherical, flattened underside. Apical system: Disc small, no tubercles, but epistromal ornament; all ocular plates exsert (dicyclic); double ocular pores near the outer edge; plates firmly connected to corona; four large plates covering oblique periproct forming an anal valve.

C

D

Fig. 4.121: Characteristic features of Arbaciidae. (A) Apical system with four large periproctal plates. Scale: 3 mm. The plates are densely and irregularly covered with prominent mosaic-like spots (partly omitted for better overview). (B) Half an ambulacrum: the compound ambulacral plates consist of three elements overgrown by the primary tubercle. No scale (A. Agassiz 1881). (C) Oral side of Arbacia lixula, test diameter 43 mm; Congo. ZMH. The strong tube feet are crowded in the widened ambulacra toward the peristomial edge. The distal ends of the oral spines show the characteristic, shiny “caps”. (D) Close-up of aboral interambulacrum: the naked median zone is covered by a mosaic-like layer. Arbacia punctulata, test diameter 33 mm; Florida, USA.

204 

 4.2 Subclass Euechinoidea Bronn, 1860

Ambulacra: Narrow and straight; 3 pore pairs per compound plate, uniserial with elongate and conjugate pores associated to suckerless podia; widened on oral side to distinct phyllodes with rounded pores and strong suckered tube feet; a single tubercle to each plate. Interambulacra: Plates wide; 2–5 subequal primary tubercles in horizontal series; more or less naked median area. Peristome: Rounded pentagonal and very large; shallow buccal notches with smooth tags, ambulacra also indented; peristomial membrane set with very small platelets and buccal plates. Spines: Primary spines in length usually hardly reaching test diameter; at oral side distally with shining “caps”. The genus consists of five species: Arbacia dufresnii Blainville, 1825. Around southern South America and sub-Antarctica. Arbacia lixula Linné, 1758. Mediterranean, East Atlantic, and Brazil. Arbacia punctulata Lamarck, 1816. Eastern USA, Caribbean. Arbacia spatuligera Valenciennes, 1846. West coast of South America. Arbacia stellata Blainville, 1825. West coast of South America, Galapagos Islands. Biology: The members of this genus mostly live in littoral to sublittoral waters where strong wave motion occurs. In adaptation to this habitat, they have developed solid tests with short, thick spines, which do not exceed the diameter of the test. With these spines, they are able to wedge themselves between the rocks during daylight, at night coming out to graze, mostly on algae. Animals living in shallow water have spines shorter and stouter than those living some meters deeper, where the effects of the waves are less distinct. Numerous strong podia are developed in the widened pore zones of the oral side. They have broad sucking discs for attachment to the hardground. In contrast, the tube feet of the upper side are modified to respiration papillae with thin walls as they have lost the capacity of suction. That is the reason why the species of Arbacia cannot mask the upper side of their tests with particles against light and predators  – unlike many other shallow water sea urchins. Nor can they right themselves again after being turned upside down. Arbacia is the only shallow-water genus with members living in both high and low latitudes. It originated in temperate waters of South America and gave rise to three species along the west coast. By the closing of the Isthmus of Panama, they were separated from the Atlantic, where two further species developed divided by the Mid-Atlantic barrier. However, Arbacia lixula is the only echinoid species that overran this barrier and reached Brazil (Lessios et al. 2012).

The very characteristic genus is known as fossil since the Miocene. Literature: Bernasconi 1953; Serafy 1979; Hendler et  al. 1995; Lessios et al. 2012. Arbacia dufresnii Blainville, 1825 (Fig. 4.122 A, B) Test: Low hemispherical, oral side flattened, horizontal diameter up to 50 mm. Apical system: Naked, madreporite slightly enlarged; distinct layer of stereom on all plates. Ambulacra: Pore zones narrow above the ambitus, conspicuously widened toward the peristomial edge; primary tubercles in two regular series, on the upper side rather small, adapically alternating; at the ambitus abruptly larger, as large as in interambulacra. Interambulacra: Broad, naked median zones from the apex down to the ambitus, bordered only by small primary tubercles, increasing continuously in size, around the ambitus largest and arranged in two or more short vertical series, covering the whole width of interambulacral plates. Peristome: Margin sinuous due to protruding ambulacral pore zones; broad, but shallow buccal notches with tags. Spines: Short and stout, longest at the ambitus; oral spines with shiny “caps”. Color: The spines are dark purplish or blackish; the denuded test greenish with darker pore zones. The naked interambulacral median zones and apical plates are brightly green; the oral side is whitish. Distribution: Arbacia dufresnii is known from the southern coasts of South America, from the mouth of the La Plata in Argentina to Puerto Montt in Chile, also from the Falkland Islands and the Subantarctic. It lives from the shore down to about 310 m. Arbacia lixula Linné, 1758 (Fig. 4.121 C, 4.122 C–E) Test: Horizontal diameter up to 80 mm. Apical system: Naked, madreporite enlarged; genital and ocular plates finely spotted like a mosaic. Ambulacra: Narrow aborally, on the oral side widened; two series of tubercles, near the apical disc alternating or even becoming a single series. Interambulacra: Naked median space inconspicuous, more distinct in younger specimens than in adult; often spotted like the apical plates; numerous tubercles of similar size arranged in vertical and horizontal rows. Peristome: Very large, pore zones protruding at the margin, buccal notches broad and shallow associated with conspicuous “tags”. Spines: Short and stout, tip pointed, on the oral side distally with shiny “caps”.

4.2.8 Order Arbacioida Gregory, 1900 



A

 205

B

C

E

D

Fig. 4.122: (A, B) Arbacia dufresnii. (A) Aboral side of test, diameter 35 mm; Fireland, Argentina. ZMH. In the interambulacra, the green, naked areas are sharply separated from the tuberculated zones set with spines. (B) Aboral side with spines, diameter of test 15 mm; Caleta Olivia, Patagonia, Argentina. The green areas and the apical system are covered with a layer of prominent, mosaic-like spots. (C–E) Arbacia lixula. (C) Oral side of test, diameter 48 mm; Sardinia, Italy. The peristome is very large. The peristomial edge is sinuous, “tags” are associated with the shallow buccal notches. (D) Side view: there are up to 6 tubercles in a horizontal series on one interambulacral plate. The naked zone is narrow. (E) Aboral side of test, diameter with spines 55 mm; Malta, Mediterranean. The spination is dense, in other specimens the spines may be less closely packed. The tips are sharp.

206 

 4.2 Subclass Euechinoidea Bronn, 1860

Color: In life, the test and the spines are black. The bare test is reddish brown or reddish orange to light pink, mostly with darker pore zones and darker heads of tubercles. Distribution: This species is known from the Mediterranean and the adjacent coasts of the Atlantic to the Cape Verde Islands and the Gulf of Guinea, West Africa (var. africana); also known from the Canaries, Madeira, the Azores, and Brazil having crossed the Mid-Atlantic barrier. It lives from the littoral zone to a depth of 40 m. Arbacia punctulata Lamarck, 1816 (Fig. 1.123) Test: Low hemispherical or subconical, diameter up to 50 mm. Apical system: Without tubercles, prominent mosaic-like spots; madreporite distinctly enlarged. Ambulacra: Pore zones conspicuously widened on the oral side; two series of tubercles, on the upper side, small and irregular, becoming larger rather abruptly at the ambitus and toward the peristome. Interambulacra: Naked median zones distinct, only two series of tubercles at the outer margins of the plates, increasing in number toward the ambitus, up to 8 tubercles of equal size in a horizontal series on the oral side.

A

Peristome: Very large; pore zones in ambulacra protruding, buccal notches with tags. Spines: Solid, tapering to a pointed tip, length about half the test diameter, longest around the ambitus; oral spines with marked distal “caps”. Color: In living specimens, the test and the spines are dark brown to purplish, but it can vary to reddish, pinkish, or almost black. The spines become often gradually whitish to the base. The bare test may also be light brown or light pink with darker pore zones and darker radial patterns in the interambulacra. Biology: Arbacia punctulata lives in turtle grass beds, on coral reefs under boulders, on sandy, shelly, or rocky bottoms, singly or in groups. It grazes on algae and sea grass, and it is also reported to feed on sponges, coral polyps, juvenile sand dollars, and even on members of its own species. Distribution: This species is found from Cape Cod, Massachusetts, southward to Florida and the Gulf of Mexico to the Yucatan Peninsula, and from Panama to Barbados and French Guyana. It occurs from the littoral zone to a depth of about 225 m, but prefers water of less than 50 m.

B

C

Fig. 4.123: Arbacia punctulata. (A) Aboral side of test, diameter 33 mm; Florida, USA. The naked zones in the interambulacra are broad. (B) Side view of test, diameter 23 mm; Florida, USA. Only around the ambitus and on the oral side, secondary tubercles occur on the interambulacral median zones. (C) Aboral side with spines, diameter of test 28 mm; Florida, USA. The spines are solid tapering slightly to the blunt end.



4.2.8 Order Arbacioida Gregory, 1900 

 207

Arbacia spatuligera Valenciennes, 1846 (Fig. 4.124 A–C) Test: Diameter may reach more than 70 mm. Apical system: Anal plates often raised, forming a pointed cone. Interambulacra: Naked median zones rather narrow, bordered by more than one series of tubercles down from the apex. Spines: Short and thick on the upper side, almost clubshaped; sometimes bending over the ambulacra, longer at the ambitus. Color: The test and the spines are usually dark brown to purplish, the spines may be lighter. Distribution: This species is known along the west coast of South America from Guayaquil, Ecuador, to south Chile, living from the ebb zone to a depth of 25 m.

Spines: Length 2 mm, flattened, in cross section triangular, well developed distal “cap”. Color: White and red lines on green brownish base, primary spines with red distally and white tips; color of oral side whitish. Biology: Arbaciella elegans is found on the shells of the bivalve Pinna, grazing on algae. Recently, the species was discovered in the crevices of Lithotamnion, an incrusting red alga. It is likely this species is more widespread than hitherto known because of its hidden habitat. Distribution: This species occurs in the western Mediterranean and in the eastern Atlantic from Morocco along the west coast of Africa southward to Angola. Literature: Mortensen 1910; Giacobbe & Rinelli 1992; Baumeister & Koch 1998.

Arbacia stellata Blainville, 1825 (Fig. 4.124 D, E) This species resembles Arbacia spatuligera differing in the following features: Interambulacra: Naked median zone bordered by a single row of tubercles on each side. The spines are conspicuously longer and more slender. Color: The cleaned test is white, often with alternating and slightly angular red spots on the naked median zones. Distribution: Arbacia stellata is known from Baja California, Mexico, to northern Chile, including the Galapagos Islands. It lives in the littoral zone down to a depth of 10 m.

Genus Coelopleurus L. Agassiz, 1840 The genus has been widely distributed worldwide since the Tertiary. A. B. Smith has separated the very numerous extinct and extant species into four subgenera. According to his work, all extant species, living predominantly in the tropics, fall into the subgenus Keraiophorus Michelin, 1862. They are characterized by very long primary spines that are on the aboral side, restricted to the ambulacra. They are more or less curved upward. The aboral interambulacra are in the main naked. (Fig. 4.126 A–C) Test: Low, flattened above and below or hemispherical or subcircular, circumference often slightly pentagonal. Apical system: Dicyclic, genital plates pentagonal and larger than ocular plates; ring of small tubercles bearing pedicellariae around the periproctal edge; otherwise, all plates rather naked, but covered by epistromal patterns of ridges; periproct with four, rarely five large anal plates. Ambulacra: Usually inflated; primary tubercles very large, decreasing in size toward the apical disc; pore pairs in steep arcs of three, on upper side rather distant from each other, around the ambitus constrainted between the large areoles, slightly expanded at peristomial edge. Interambulacra: More or less broad naked median area on aboral side; large primary tubercles only around the ambitus, yet smaller than in ambulacra, very small tubercles along the adradial suture, more or less continuing to the apical disc; large areoles slightly raised and set off against the plates. Peristome: Very large, half the diameter of the test or more; membrane rather naked, buccal notches shallow and with tags. Spines: Very slender, primaries much longer than diameter of test, longest on ambital ambulacra; more or less curved upward; oral primaries slender and much shorter, often flattened; tip with a short cap; cross

Genus Arbaciella Mortensen, 1910 The genus is monospecific. Arbaciella elegans Mortensen, 1910 (Fig. 4.125) Test: Small, low hemispherical, oral side flattened; diameter up to 8 mm. Apical system: About a third of test diameter, dicyclic, four anal plates, madreporite with several pores; ocular pores below a distal process; all apical plates with elongated, inflated structures, pentagonal rim around the periproctal edge. Ambulacra: Compound plate with 3 pore pairs, pores somewhat crowded at the peristome; on the aboral side, no tubercles, but high glassy granules; only on the oral side rather large tubercles of about same size as in interambulacra carrying primary spines, one per plate. Interambulacra: Aboral side with horizontal rows of high granules or pegs, only at the ambitus and on oral side, large tubercles, up to two per plate; primordial plate wide, scarcely projecting medially, set with one primary tubercle. Peristome: Much larger than apical disc; buccal membrane scattered with very small platelets, buccal plates in pairs.

208 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

E

D

Fig. 4.124: (A–C) Arbacia spatuligera. (A) Aboral side of test, diameter 38 mm; Antofagasta, Chile, ZMH. (B) Oral side. The peristomial membrane expanded over the “tags”, which are associated with the buccal notches. (C) Side view with spines, diameter of test 62 mm; Penco, Chile. ZMH. The very short aboral spines indicate that the echinoid lived in very shallow water, the stubs giving only minimal resistance to the waves. (D, E) Arbacia stellata. (D) Aboral side of cleaned test, diameter 39 mm; Baja California, Mexico (sketch after a photo of H. van Noordenburg). There are conspicuous red spots along the interambulacral median line. (E) Aboral side with spines, diameter of test ca. 28 mm; Coronel, Chile; ZMH. Mostly the slender spines are purplish.

4.2.8 Order Arbacioida Gregory, 1900 



A

C

 209

B

D

Fig. 4.125: Arbaciella elegans. (A) Aboral side of test, diameter 7 mm; Sette Cama, Gabun. Holotype E 211, ZMH. The upper side is covered by glassy pegs, not carrying spines. Large leaf-shaped spines are confined to the ambitus. (B) Oral side of test, diameter of test 8 mm; Sette Cama, Gabun. ZMH. The peristome is very large. It is encircled by sucking podia. (C) Side view. Spines are only present around the ambitus. (D) Part of peristomial edge. The primordial plate is wide (in red). Scales: (C) 2 mm; (D) 1 mm (Mortensen 1910).

section triangular; secondary spines club-shaped or slender and more or less pointed. Color: All extant species are brightly colored on the aboral side of the test and the upper side of the primary spines; the oral side and the underside of the spines are always much paler or even white. The genus consists of ten species. Coelopleurus australis H. L. Clark, 1916. Southern Australia. Coelopleurus exquisitus Coppard & Schultz, 2006. New Caledonia. Coelopleurus floridanus A. Agassiz, 1871. Caribbean. Coelopleurus granulatus Mortensen, 1934. Malaysia. Coelopleurus interruptus Döderlein, 1910. South Africa. Coelopleurus longicollis A. Agassiz & H. L. Clark, 1908. Hawaii. Coelopleurus maculatus A. Agassiz & H. L. Clark, 1907. Indo-West Pacific. Coelopleurus maillardi Michelin, 1862. Indo-West Pacific.

Coelopleurus undulatus Mortensen, 1934. Japan and South China Sea. Coelopleurus vittatus Koehler, 1927. Malaysia. Literature: Mortensen 1935; Pawson & Miller 1979; Coppard & Schultz 2006; Mironov 2006. Coppard 2010. Coelopleurus australis H. L. Clark, 1916 (Fig. 4.127 A, B) Test: Subcircular. Interambulacra: Naked area rather narrow and short with undulating edges constricted to the inner half of the plates; the outer sides are well covered by a couple of secondary and 10–20 miliary tubercles. Spines: Primaries slightly curved, secondary spines pointed. Color: The primary spines are not really banded but basally olive to apple green, the shaft becoming upward bright red, toward the tip sometimes with one or two broad bands in light green. The interambulacral naked areas are lilac and have an undulating line in purple and red borders.

210 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

B

C

D

Fig. 4.126: (A–C) Typical features of Coelopleurus. (A) Apical system with four large anal plates and epistromal patterns on the plates. (B) The cross section of the primary spines is triangular. (C) The ambulacral primary tubercles decrease in size toward the apical system the pore pairs being constrainted. Scales: (A) 3 mm; (B) 0.5 mm; (C) 5 mm (Mortensen 1935). (D) Coelopleurus longicollis. Side view with spines, diameter of test 34 mm, longest spine 160 mm; Bohol, Philippines. Only a few primary spines remain in their full length; most of them are lost. The color of the primary spines is variable, white, banded in white and red or uniformly red. The collars are very long, up to 32 mm.

4.2.8 Order Arbacioida Gregory, 1900 



A

 211

B

45 mm 45 mm

D

C

E

Fig. 4.127: (A, B) Coelopleurus australis. (A) Aboral side with spines, diameter 45 mm; Bass Strait, southern Australia. Holotype and only known specimen (photo by Kate Attwood, ©Australian Museum, Sydney). (B) Close-up of aboral side. (C–E) Coelopleurus exquisitus. (C) Aboral side with spines, diameter of test 29 mm; New Caledonia. The primary spines are narrowly banded in bright red. The base is lavender, as also the broad naked areas in the interambulacra, the lighter undulating line is very conspicuous. (D) Aboral side of test, diameter 38 mm; New Caledonia. (E) Side view.

Occurrence: The holotype was found in the Bass Strait, southern Australia, at a depth of about 400 m. Coelopleurus exquisitus Coppard & Schultz, 2006 (Fig. 4.127 C–E) Test: Upper side hemispherical or slightly conical, oral side flattened.

Interambulacra: Naked area broad with straight edges; only a few small tubercles along the adradial suture. Peristome: Distinctly larger than in the other species of Coelopleurus. Spines: Primaries curved; secondary spines slender and tapering to a blunt tip.

212 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

Fig. 4.128: (A, B) Coelopleurus floridanus. (A) Side view of test, diameter 49 mm; off Cape Hatteras, east coast of USA. ZMUC. The large areoles are distinctly set off against the surface of the plates. (B) Aboral side with spines, test diameter 34 mm; off Cape Hatteras. USA. ZMUC. (C) Coelopleurus granulatus. Aboral side partly with spines, diameter of test 29 mm; Amboina Bay, Indonesia. Holotype and only known specimen. ZMUC ECH 493.

Color: The naked area is a well-defined red lavender, flanked by a narrow greenish orange band. Across the lavender runs a lighter, broadly undulating line. The primary spines are narrowly banded in greenish and white with bright red. It is remarkable that this species shows almost no variation in shape and coloration. Distribution: Coelopleurus exquisitus seems to be endemic to New Caledonia and off Vanuatu in deeper water. There is a very large population off Nouméa. It was reported that sometimes a dredge was almost exclusively filled with specimens of that species. Coelopleurus floridanus A. Agassiz, 1871 (Fig. 4.128 A, B) Test: Subspherical, aborally and orally flattened; maximum diameter about 50 mm. Apical system: In males, tubular genital papillae (during spawning); in females, conical papillae. Interambulacra: Naked median area broad and straight; primary tubercles surrounded by many small ones. Spines: Primaries curved, length of collar very variable, between 15 and 30 mm; whole length of spines may reach 3 time the test diameter; secondary spines slender with blunt tip. Color: Naked interambulacral area with brownish transverse patches on light, well-defined ground, adapically bordered by red; ambulacra brown with red median spaces; primary spines banded in red and cream or not banded with bright red distally. Distribution: The species is known from the east coast of the USA as far north as Cape Cod through the West Indies to Suriname; also on the seamounts in the eastern Atlantic. Bathymetric range 40 to 2,380  m (A. Mironov 2006 supposes the deep-sea records, below 530 m, being a case of erroneous labeling). Remarks: According to Mironov (2006), Coelopleurus floridanus is one of the most common members of the invertebrate megafauna in the Great Meteor Plateau in the northeast Atlantic, often dominating the benthic community. Coelopleurus granulatus Mortensen, 1934 (Fig. 4.128 C) Test: High and inflated, aboral side and apical plates densely covered by very small tubercles bearing triphylous and tridentate pedicellariae. Interambulacra: Naked areas moderately broad and almost straight. Pedicellariae: Aborally on ambulacra and interambulacra and on apical plates abundantly distributed triphylous and tridentate ones, ophicephalous ones only around the peristome.



Spines: Primaries slightly curved, secondaries slender and pointed. Color: Naked areas in lavender with darker transverse patches, bordered by a bright red line; primary spines partially banded in greenish with red or purplish. Occurrence: Found at Amboina, Indonesia. Depth about 200 m. Coelopleurus interruptus Döderlein, 1910 Test: Subcircular. Interambulacra: Broad, straight-edged naked median zones. Spines: Primaries straight and relatively solid; secondaries tapering to the pointed tip. Color: The naked median areas are brown with a lilac zigzag line and white edges, which are bordered adradially by a red line. The median zones of the ambulacra are red as well. The primary spines are unbanded being a uniform dull purple red. Distribution: Found on the Agulhas-Bank, South Africa. Depth 45 to 140 m. Remark: C. interruptus is very similar to C. vittatus from the Andaman Islands with the white edges along the naked zones and the straight primary spines. It is likely that the two species are closely related and therefore clearly differentiated from the other Coelopleurus species. Coelopleurus longicollis A. Agassiz & H. L. Clark, 1908 (Fig. 4.126. D) Test: Low, aboral side convex, oral side slightly concave. Interambulacra: Naked areas with slightly undulating edges; outer parts of the plates densely set with rather large, irregularly arranged tubercles. Spines: Primaries distinctly curved, length 3 times the test diameter; very long collar; secondaries slender and tapering toward the tip. Color: Well-limited naked area more or less cream or light lavender with oblique patches, bordered by bright red, median line of ambulacra also light red. Primary spines uniformly white or rarely banded with red or entirely red. Distribution: Philippine seas. Bathymetric range 150 to 240 m. Coelopleurus maculatus A. Agassiz & H. L. Clark, 1907 (Fig. 4.129 A, E, H) Appears to be the most common species of Coelopleurus in Philippine waters but is often confounded with C. maillardi. Test: Diameter may reach 35 mm. Interambulacra: Naked areas rather short and narrow with slightly undulating edges.

4.2.8 Order Arbacioida Gregory, 1900 

 213

Secondary spines: Club-shaped. Color: The primary spines are banded in red and greenish white. The color of the naked interambulacral median spaces may be very variable: the undulating line in lilac, lavender, or pink, bordered by a narrow line in purple, red brown, or bright red. The spical plates are green to brownish. Distribution: Widespread in the Indo-West Pacific. About 200 to 400 m. Coelopleurus maillardi Michelin, 1862 (Fig. 4.129 B, C, F, I) Test: Low hemispherical, rather flattened above and below; in outline, often pentagonal; maximum diameter 40 mm. Apical system: Ocular plates with radiating ridges, less developed ridges on the genital plates; single circle of tubercles around the periproctal edge; four large anal plates. Ambulacra: Of same width as interambulacra, distinctly raised aborally, very large primary tubercles; pores small and close-set per pair. Interambulacra: Naked zones broad and straight edged, bordered by a series of small secondary tubercles. Spines: Primaries gently curved, secondaries short, slender, and pointed. Color: The naked interambulacral median space is light lilac to purple with oblique patches in light pink or lavender, bordered by a red vertical band. The primary spines are spotted or banded in light green and purplish red down the entire length of the shaft including the collar. Distribution: Coelopleurus maillardi is known in the whole Indo-West Pacific and the Malayan region from the east coast of Africa, as far south as Natal, to the Philippines. Bathymetric range 70 to 300 m. Coelopleurus undulatus Mortensen, 1934 (Fig. 4.130) Test: Low hemispherical. Ambulacra: Pore pairs relatively small. Interambulacra: Naked area very narrow and undulating, otherwise covered by numerous small tubercles. Peristome: Rounded pentagonal. Spines: Primaries curved, collar up to 8  mm; secondary spines short and club-shaped. Color: Test reddish brown, undulating line in interambulacra a light lavender; primary spines not banded, but proximally green, distally red. Some specimens show a distinct red along the undulating lines or the whole surface is red except the undulating lines and the tubercles. Distribution: Japan and northern South China Sea. Bathymetric range 200 to 400 m.

214 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

E

D

H

F

G

I

Fig. 4.129: (A) Coelopleurus maculatus. Close-up of aboral side with spines, diameter of test 24 mm; Indonesia. ZMUC. The spines are narrowly banded in bright red and greenish white. The secondary spines are club-shaped. (B, C) Coelopleurus maillardi. (B) Aboral side with spines, diameter of test 23 mm; off Natal, South Africa. The tips of the spines are broken. The naked interambulacral zones are brightly colored, the spines being banded. (C) Close-up of interambulacrum. Scale: 5 mm. (D–F) For comparison, aboral side. (D) Coelopleurus exquisitus; (E) Coelopleurus maculatus, F. Coelopleurus maillardi. (G–I) Oral side. The peristome of C. exquisitus is distinctly larger than in the other species.

Coelopleurus vittatus Koehler, 1927 Test: Subcircular. Interambulacra: Naked interambulacral areas broad and straight edged. Spines: Primaries straight and rather solid; secondaries tapering to a pointed tip. Color: The naked median areas are light brown with a lilac zigzag line and light-colored borders. The adradial zones are red as well as the median areas in the ambulacra. The primary spines are unbanded in green with red distally. Occurrence: The holotype was found off the Andaman Island at a depth of 140 m. The order Arbacioida includes further four genera with seven species that are small to very small. Some of them are known only from the type specimen, and

all of them, except Arbaciella, were taken in deep to bathyal waters: in these species, the primordial plates in the interambulacra are recognizable in adults (see Fig. 4.131). Genus Dialithocidaris A. Agassiz, 1898 Dialithocidaris gemmifera A. Agassiz, 1898 (Fig. 4.131 A1–4) Test: Small, low, subconical; flattened on the oral side. Apical system: Large, dicyclic; anal opening comparatively small, covered by 4 plates; all apical plates with small granules; gonopores not known. Ambulacra: Pore pairs trigeminate, arranged in a single series; short phyllodes; one primary tubercle per plate. Interambulacra: Plates rather wide; oral plates with two primary tubercles, on aboral side the primaries reach only

4.2.8 Order Arbacioida Gregory, 1900 



A

B

 215

C

Fig. 4.130: Coelopleurus undulatus. (A) Aboral side with spines, diameter of test 33 mm; Sagami Bay, Japan. ZMUC ECH 337. There is an undulating band in the interambulacrum. (B) Oral side: the colors on test and spines are much paler than on the aboral side. (C) Coelopleurus undulatus. Diameter of test 39 mm; Sagami Bay, Japan. ZMUC. Side view with spines.

half the way to the apex, adapical plates with horizontal rows of pegs, not bearing spines; primordial plate small and not prolonged upward. Peristome: About half the diameter of test, buccal notches wide and shallow; off the ambulacra large oval areas containing very small plates. Spines: Flattened, with a glassy cap. The holotype was taken off the Caribbean coast of Panama (Mariato Point) at a depth of 3,255 m.

Valves of tridentate pedicellariae flat with nearly parallel sides. The genus consists of two very similar species: Habrocidaris argentea A. Agassiz & H. L. Clark, 1908. Central Pacific, recorded from Hawaii and the Sala y Gomez Ridge. Habrocidaris scutata A. Agassiz, 1889. West Indies and northeast Atlantic seamounts. Literature: Mironov 2006.

Genus Habrocidaris A. Agassiz & H. L. Clark, 1907 Test: Aboral side low hemispherical, oral side flattened. Apical system: Large, dicyclic, anal opening small and covered by 5 plates, gonopores in distal part of genital plates; all apical plates with small granules. Ambulacra: 4–5 most adoral plates with a single pore pair, the following ones are trigeminate, arranged in a single series; tubercles bearing spines only around the ambitus; aboral plates with small irregularly arranged pegs. Interambulacra: Wide plates; oral plates each with a single tubercle plus one on the median suture; primordial plates projecting along the median line carrying one or more tubercles; a low ridge connects the primary tubercle of the primordial plate and the neighboring paired plates; aboral plates with small irregularly arranged pegs. Peristome: Densely plated; buccal notches inconspicuous. Primary spines: Flattened with triangular cross section; distal “cap” present; secondary spines lacking.

Habrocidaris argentea A. Agassiz & H. L. Clark, 1908 (Fig. 4.131 B1–3) Maximum diameter 21.3 mm. Primary spines: On the primordial and the two neighboring plates with a widened and thorny basal part, different from the other oral primaries. Distribution: Reported from Hawaii and from the Sala y Gomez Ridge, southeastern Pacific. Bathymetric range 570 to 750 m. Remarks: There are only a few morphological features that differentiate the two species: Habrocidaris argentea has a more pentagonal and larger peristome, the peristomial plates also being larger than in H. scutata. The buccal plates are clearly visible among the surrounding plating, while in H. scutata, they are comparatively indistinct. Additionally, the valves of the tridentate pedicellariae are narrower than in H. scutata. Mortensen (1935) and Mironov (2006) emphasize further the single small tubercle beside the primaries on the primordial and first paired interambulacral plates of H. argentea, while in

216 

 4.2 Subclass Euechinoidea Bronn, 1860

H. scutata, they carry more than 1 (2–4) small tubercles. Also, the geographic distribution distinguishes the two species, H. argentea living in the Pacific and H. scutata occurring in the Caribbean. Habrocidaris scutata A. Agassiz, 1889 (Fig. 4.131 C1–4) Maximum diameter 17.5 mm. Primary spines: On the primordial and the two neighboring plates with widened and serrated basal part, different from the other primaries. Color: In alcohol, the test is silvery with a brown tint, ocular plates with darker median area; tubercles white; tips of the tube feet darker than the test. Distribution: Off St. Cruz, Lesser Antilles. Depth 1,045 m and off northern Cuba, 915  m. Also dredged on the northeast Atlantic seamounts at depths of 760 to 1,900 m. Genus Podocidaris A. Agassiz, 1869 Test: Low hemispherical, oral side flattened, diameter of test up to 11 mm. Apical system: Dicyclic, anal opening small, covered by 4 plates; apical plates with small granules, which are often connected by elevated ridges; gonopores central. Ambulacra: Pore pairs trigeminate, in one straight line throughout, every third a little larger; 1 tubercle per plate on the oral side. Interambulacra: Plates wide; primordial plate projecting medially and set with a single tubercle, the other oral plates carrying 2 tubercles. On aboral side, either on ambulacra or interambulacra no tubercles, but slender pegs, arranged in vertical and horizontal series. Peristome: Broad plated space inside the ring of buccal plates, the membrane outside is naked. Spines: Flattened, distinct keel at the upper side (cross section triangular), sometimes even leaf-shaped, distally with shining cap, mainly confined to the lower side.

Three species are included in this genus: Podocidaris ornata H. L. Clark, 1912. Hawaii. (Fig. 4.131 E) Podocidaris sculpta A. Agassiz, 1869. Caribbean, mostly in the Strait of Florida and northeast Atlantic seamounts. (Fig. 4.131 D1–3) Podocidaris sibogae Mortensen, 1934. One young specimen from the Kei Islands. Remarks: Podocidaris ornata and P. sculpta are very similar. Mortensen emphasized the greenish tinge of P. ornata, while P. sculpta shows no green. H. L. Clark (1912) felt that the sculpture on the apical plates of P. ornata is stronger developed than in P. sculpta. Genus Pygmaeocidaris Döderlein, 1905 Pygmaeocidaris prionigera A. Agassiz, 1879 (Fig. 4.131 F1–4) Test: Small, low, in larger specimens higher, subconical, oral side flattened, diameter of test not reaching 15 mm. Apical system: Very large, periproct relatively small with 5 valves; gonopores could not be determined with certainty; a few granules scattered on the apical plates. Ambulacra: Pore pairs trigeminate; uniserial, but tending to form arcs adorally; 1 tubercle per plate on oral side and continuing around the ambitus, upper plates each with a larger granule. Interambulacra: One to two primary tubercles per plate on oral side and around the ambitus, a single tubercle on the conspicuously prolonged primordial plate; aborally, only a few scattered pegs. Peristome: Membrane naked, buccal plates small, off each ambulacrum a cushion-like oval area (like in Dialithocidaris). Spines: Primaries flattened, slender, and distally strongly serrated. Color: Creamy whitish (faded out?). Distribution: This species is known from north of New Guinea to the Bay of Bengal. Depth 660 to 2,860 m.

▸ Fig. 4.131: (A) Dialithocidaris gemmifera. Diameter of test 21 mm; Panama, Caribbean (A. Agassiz 1904, no scale). (A1) Primary spine.

(A2) Oral side. (A3) Aboral side. (A4) Side view. The tuberculation is restricted to the lower part of the test, on the upper part there are only granules. (B) Habrocidaris argentea. Test diameter 11.5 mm; northwest of Kauai, Hawaiian islands. (Holotype: A. Agassiz & H. L. Clark 1908, no scale). (B1) Aboral side: tubercles are lacking; there are only small, irregularly scattered granules. (B2) Oral side: the peristome is densely plated, the buccal plates are distinctly visible. (B3) Interambulacral plate: the primordial plate (shaded) projects along the median line, the following median suture is set with an odd tubercle. (C) Habrocidaris scutata. Test diameter 17.5 mm; St. Croix, Antilles (A. Agassiz & H. L. Clark 1908). Holotype. (C1) Aboral side only with small granules. (C2) Oral side: the buccal plates are not distinguishable between the surrounding plating. (C3) Side view. (C4) Interambulacral plate: the primordial plate (shaded) projects upward. (D) Podocidaris sculpta. (D1) Side view, diameter of test 11 mm; Caribbean between Florida and Cuba. Scale: 4 mm. A. Agassiz 1872. (D2) Part of peristome. The flower-like structures are large, suckered buccal podia. The area inside the ring of buccal plates is densely plated, whereas the membrane outside is totally naked (shaded). (D3) Part of apical disc: the plates are sculptured by granules and small ridges. Scale: 1 mm (Mortensen 1935). (E) Podocidaris ornata. Aboral side of test, diameter 9 mm; Hawaii Island. Scale: 5 mm (H. L. Clark 1912). (F) Pygmaeocidaris prionigera. (F1) Side view of test, diameter of test 5 mm; Sumatra (Döderlein 1906). (F2) Part of apical system. Scale: 4 mm. (F3) Adoral part of interambulacrum: the primordial plate (shaded) is distinctly prolonged upward. (F4) Adoral part of ambulacrum: the pore pairs are slightly crowded along the peristomial edge. Scale: (E2–E4) 2 mm (Mortensen 1935).

4.2.8 Order Arbacioida Gregory, 1900 



A 1

2

3

4

B 1

2

3

C 1

2

D

3

4

E

2 1

3

F 1

2

3

4

 217

218 

 4.2 Subclass Euechinoidea Bronn, 1860

Remarks: This species differs from the other very small arbaciids by the presence of only a few pegs on the aboral side. Genus Tetrapygus L. Agassiz, 1841 The only species of the genus is the largest of all Arbacioids being characterized by the presence of 4 to 5 pore pairs per ambulacral plate and the lack of a naked median area in the interambulacra. Tetrapygus niger Molina, 1782 (Fig. 4.132) Test: Solid, low hemispherical, oral side flattened, diameter up to 75 mm. Apical system: Mostly with all ocular plates insert; in younger specimens, variable, four large anal plates; madreporite conspicuously enlarged. Ambulacra: Narrow aborally, 4 or 5 pore pairs to each plate, may be mixed in a single column, on the oral side pore zones conspicuously widened to broad phyllodes; two regular series of tubercles, with small ones scattered between. Interambulacra: No naked space in median areas; on the aboral side tubercles of different sizes, often two horizontal series on one plate, the lower tubercles large, the upper ones small and irregularly arranged; at the ambitus and on the oral side, equal-sized tubercles in regular horizontal rows; plates at the peristomial edge very narrow. Peristome: About half the diameter of test, margin very sinuous with protruding pore zones and shallow buccal notches associated with tags; peristomial membrane covered with small plates.

A

B

Spines: Largest around the ambitus, oral primaries with small, glassy caps at the distal ends. Color: In life, the test and the spines are black to dark purple. The denuded test is whitish with darker pore zones and black apical system, the median space of the interambulacra is tinted dark purplish. The heads of the tubercles are often a beautiful violet. The oral side is a uniform whitish with light violet tubercles. Biology: The aboral spines are very short and stout in individuals living in shallower, more turbulent habitats; in specimens from deeper water, they may be longer and more slender. Distribution: This species lives along the west coast of South America in Peru and Chile from the shore down to a depth of about 10 m. Remarks: Tetrapygus niger differs from the species of Arbacia in the tuberculation of the interambulacra: the former has a series of larger tubercles and above them some smaller ones, the latter has only a single row of equal-sized tubercles. In Tetrapygus niger, there are 4 to 5 pore pairs per ambulacral plate; in Arbacia, always only 3.

4.2.9 Order Camarodonta Jackson, 1912 The most advanced jaw apparatus is the camarodont lantern, where the two hemipyramids are connected by a bow, like that of the members of the order Camarodonta, which are equipped with the strongest jaw apparatus ever developed in regular echinoids. (Fig. 2.10) Their ambulacral plates show echinoid-style compounding. Mostly, the tubercles are non-crenulated.

C

Fig. 4.132: Tetrapygus niger. (A) Aboral side of test, diameter 64 mm; Caldera, northern Chile. The interambulacral plates are set with numerous tubercles of diverse size. (B) Oral side: the pore zones are conspicuously widened at the peristomial edge. Consequently, the interambulacra are very narrow. The buccal notches are shallow and the tags small. (C) Aboral side with spines, diameter of test 52 mm, Caldera, Chile. The spines are longest at the ambitus.

4.2.9 Order Camarodonta Jackson, 1912 



B

A

 219

C

E D

Fig. 4.133: Parasalenia gratiosa. (A) Apical system: the genital plates project into the interambulacra. There are few periproctal plates. (B) Ambulacrum: the small pore pairs are arranged in steep arcs of three, the primary tubercles are large. Scale: 2 mm (Mortensen 1943). (C) Aboral side with spines, length of test 31 mm, width 26 mm; Malaysia. The milled rings at the base of the spines are conspicuously white. (D) Aboral side of test, length 26 mm, width 20 mm; Malaysia. The apical system is elongated and strongly pentagonal; the plates itself got lost. (C, D, sketches after photos of H. van Noordenburg).

The following camarodont family is clearly differentiated from the two infraorders Temnopleuridea and Echinidea and is treated separately (Kroh & Smith 2010).

4.2.9.1 Family Parasaleniidae Mortensen, 1903 Genus Parasalenia A. Agassiz, 1863 The genus is characterized by an elongated test, conspicuously pointed genital plates and a bright white milled ring. It consists of two rather similar species: Parasalenia gratiosa A. Agassiz, 1863. Tropical IndoPacific. Parasalenia poehlii Pfeffer, 1887. Tropical Indo-Pacific.

Parasalenia gratiosa A. Agassiz, 1863 (Fig. 4.133) Test: Regularly domed with flattened upper side and concave oral side; elongated, axis along A III and IA 5; oral side in the whole concave, aboral side may be flattened; length up to 36 mm. Apical system: Large and elongated, genital plates pointed and extending into interambulacra; ocular plates usually all exsert; ocular pores distally positioned and often offset; all plates virtually naked; 4 to 5 valve-like periproctal plates, or at least rather few. Ambulacra: 3 pore pairs forming an erect arc, becoming crowded only at the very peristomial edge; two series of large primary tubercles, which reduce in size and disappear close to the apical system; very small secondaries along the median line.

220 

 4.2 Subclass Euechinoidea Bronn, 1860

Interambulacra: Very large primary tubercles occupying almost entire height of plates; irregular, much smaller secondaries on outer side, and even smaller secondaries along the narrow median space. Peristome: Very large and elongated; buccal plates paired and covered with pedicellariae, membrane rather naked; notches broad and shallow. Spines: Primaries cylindrical, tapering to the simple point; finely ridged; length approximately as long as diameter of test; secondaries small. Color: Generally, the spines of the living animal are uniformly black or greenish olive; sometimes, they may be more or less banded, especially in young specimens. The milled ring at the base of the primary spines is prominent and conspicuously white, “like a chain of pearls” (Mortensen). The bare test is whitish, the upper side often darker. Sometimes, the genital plates are green and the interambulacra are tinted in greenish. Distribution: This species is known all over the Indo-West Pacific from Zanzibar and Madagascar to the Tuamotu Islands, from southern Japan to Queensland, Australia. It lives from the littoral down to 70 m. Remarks: Parasalenia gratiosa is distinguished from the likewise elliptical Echinometra mathaei by the prominent milled ring, the larger apical system with its characteristically projecting genital plates, and the narrow pore zone with its erect arcs of three. Parasalenia poehlii Pfeffer, 1887 Very much like Parasalenia gratiosa. Test: Seems to be more elongated than in Parasalenia gratiosa; as small form, not reaching 20 mm.

A

B

Color: The spines are banded with red and white or red and green, the bare test is light greenish olive. The apical plates are more or less red or purplish, the primary tubercles pink. Distribution: The species is widespread over the IndoPacific, from the Gulf of Suez Tahiti and the Gilbert Island and from the Macclesfield Bank, China Sea, to Queensland, Australia. Bathymetric range from the littoral to about 70 m. The order Camarodonta contains beside the family Parasaleniidae two natural groups: Infraorder Temnopleuridea: characterized by test ornamentation like pits and grooves and a dicyclic apical system. Infraorder Echinidea: characterized by a test without ornamentation and a usually hemicyclic apical.

Infraorder Temnopleuridea Kroh & Smith, 2010 The Infraorder comprises two families: Temnopleuridae A. Agassiz, 1872. 13 genera. Trigonocidaridae Mortensen, 1903. 6 genera. In the Eocene period, many Temnopleuridea occurred in northwestern Europe as also in South Australia. Some of them had developed brood pouches in diverse forms on the upper side of their test. (Fig. 4.134 A–C) Today, only one marsupiate species remained in the North Atlantic, Hypsiechinus coronatus, which carries its juveniles around the raised apical system. All other extant Temnopleuridea are confined to tropical and subtropical waters around the world.

C

Fig. 4.134: Brood-protecting temnopleuroids from the Pliocene period, Challans, Vendée, France. (A) Arbacina Pomel, 1869. Aboral side, test diameter 21 mm. Star-shaped marsupium: the plates are lost. (B) Coptechinus bardini Cotteau, 1883. Aboral side, test diameter 18 mm. The marsupium is formed by the deeply sunken apical disc, the plates being raised in the center like a chimney with the small periproct on the top. (C) Temnechinus Forbes, 1852. Aboral side, test diameter 17 mm: the marsupium is formed by the apical disc and the adapically depressed, smooth median areas in the interambulacra. In contrast to Coptechinus, the periproct in the center (plates lost) does not raise like a chimney (collection and photos: Luc Ceulemans).

4.2.9 Order Camarodonta Jackson, 1912 



 221

4.2.9.2 Family Temnopleuridae A. Agassiz, 1872

Remark: The monophyletic clade consisting of Amblypneustes, Holopneustes, and Microcyphus is lecithotrophic, which means the larvae do not feed but live from the rich yolk in the egg. They are short-living, and their distribution is restricted (Jeffery et al. 2002).

The temnopleurid test is characterized by furrows, grooves, or pits along or at the edges of the plates. (Fig. 4.135 A, B) The ecological advantage of these structures is unknown. There are 13 extant genera that are restricted to the tropical and temperate Indo-Pacific from East Africa to the Central Pacific and southern South America and from Japan to Tasmania, with the main settlement area around Australia. They are distributed from the littoral to the abyssal zone. Amblypneustes L. Agassiz, 1841. Southern Australia. Six species. Erbechinus Jeannet, 1935. Indonesia. Monospecific. Holopneustes L. Agassiz, 1841. Southern Australia. Three species. Mespilia Desor, 1846. West Pacific. Monospecific. Microcyphus L. Agassiz, 1846. Indo-Pacific. Ten species. Opechinus Desor, 1856. Japan and Indonesia. Two species. Paratrema Koehler, 1927. Indo-West Pacific. Small form, monospecific. Printechinus Koehler, 1927. Indian Ocean and Indonesia. Two species. Pseudechinus Mortensen, 1903. Southern South America, southern Australia, and New Zealand. Nine species. Salmaciella Mortensen, 1942. Indo-West Pacific. Three species. Salmacis L. Agassiz, 1841. Indo-West Pacific. Six species. Temnopleurus L. Agassiz, 1841. Indo-West Pacific. Seven species. Temnotrema A. Agassiz, 1863. Indo-Pacific. Twelve species.

Genus Amblypneustes L. Agassiz, 1841 Test: Often high, globular, or even higher than wide, eggshaped. Apical system: Small, ocular plates exsert. Ambulacra: 3 pore pairs per plate; primary tubercles small, in regular, vertical series; secondaries subequal or smaller. Interambulacra: Small primary tubercles and more or less subequal secondaries in horizontal series, fine miliaries more or less densely covering the surface of the test. Median areas: Often show fan-shaped pattern of lighter and darker stripes on each plate; a similar though less pronounced pattern is also developed in ambulacra. Peristome: Small, but larger than apical system; buccal membrane naked apart from 10 buccal plates. Spines: Primaries short and thin, secondaries and miliaries of same shape, but smaller. The characteristic pits along at the median sutures are small and more distinctly visible in young specimens than in larger ones. In adults, they are mostly absent. Biology: The sea urchins of this genus live among algae and seaweed feeding on the leaves, generally near the shore. Remarks: Amblypneustes is closely related to the genus Holopneustes. They differ in the arrangement of the ambulacral tubercles: in the former, each plate carries a primary tubercle, forming a regular, vertical, dense series; in the latter, only every second or third plate is set with a primary tubercle, and the rows look irregular.

Literature: Mortensen 1903; Philipp & Foster 1971; Jeffery & Emlet 2003; Jeffery et al. 2002; Dudicourt et al. 2005.

A

B

Fig. 4.135: (A) Temnopleurus toreumaticus, close-up of aboral side. Sharply cut furrows lead along the horizontal sutures below the primary tubercles. Scale: 6 mm. (B) Salmacis sphaeroides. Close-up of aboral side. Small pits are developed in the angles of the plate sutures (arrows). The horizontal sutures are distinctly depressed. Scale: 10 mm.

222 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

Fig. 4.136: Differences in ambulacra of Amblypneustes and Holopneustes. (A) Amblypneustes formosus: the tubercles form a regular series, each associated to a triad of pore pairs. (B) Holopneustes porosissimus: the tubercles are irregular, often only on every second or third plate. Scales: (A, B) 5 mm.

There are seven species of Amblypneustes distributed along the south and southwest coast of Australia and north New Zealand: Amblypneustes elevatus Hutton, 1872. South and western Australia and north New Zealand. Amblypneustes formosus Valenciennes, 1846. South Australia. Amblypneustes grandis H. L. Clark, 1912. Eastern South Australia. Amblypneustes leucoglobus Döderlein, 1914. Southwest Australia. Amblypneustes ovum Lamarck, 1816. Southeast Australia and Tasmania. Amblypneustes pallidus Lamarck, 1816. South and west coast of Australia. Amblypneustes pulchellus H. L. Clark, 1928. Southeast Australia and Tasmania. The species resemble each other very much, and they are difficult to distinguish because the range of variation in color, test shape, and tuberculation is wide. Literature: Baker 1972, 1983, 1998; Rowe & Gates 1995; Miskelly 1998. Amblypneustes elevatus Hutton, 1872 (Fig. 4.137) Test: Diameter up to 55 mm, rather robust. Apical system: Periproct set with tubercles. Ambulacra: Pore pairs in low arcs; poriferous zone about half the width of ambulacral plate. In ambulacra and interambulacra, the plates bear a distinct horizontal row of primary tubercles; the median areas are rather naked. Color: The primary spines are dark olive green to brownish, often with white distal ends, the secondaries are whitish. The bare test is dark gray, brownish gray, or a dull olive green, the pore zones lighter.

Distribution: Amblypneustes elevatus is the most common species of the genus. It is found in southern Australia from the Bass Strait to Tasmania and Esperance, Western Australia; further in the Northeast of New Zealand. Bathymetric range: from the littoral zone to a depth of 50 m. Remark: In comparison to Amblypneustes ovum, the primary tubercles are nearer to each other and the plates are narrower. Amblypneustes formosus Valenciennes, 1846 (Fig. 4.136 A, 4.138 A) Test: Maximum diameter 45 mm. Apical system: Periproct without tubercles. Median zones in ambulacra and interambulacra rather bare, secondary tubercles small, few miliary tubercles. Color: Primary spines red, pinkish orange or brown, secondaries paler red to fawn, miliaries white, bare test purplish red to brownish olive, pore zones lighter; very characteristic with its lens-shaped, darker patches below each primary tubercle in interambulacra forming zigzag bands in the median zones; less conspicuous in ambulacra; lighter or darker fan-shaped stripes in the median zone of each plate. Distribution: Southern Australia from the Bass Strait and Spencer Gulf to Albany, Western Australia, from the littoral to a depth of 10 m. Amblypneustes grandis H. L. Clark, 1912 Test: Maximum diameter may reach 90 mm being 1.5 the height. Apical system: Periproct with tubercles. Ambulacra: Very narrow poriferous zone. Distribution: The species is found along the southern coast of Australia from St. Vincent Bay to the Flinders Islands in the littoral.

4.2.9 Order Camarodonta Jackson, 1912 



A

 223

B

Fig. 4.137: Amblypneustes elevatus. (A) Aboral side of test, partly with spines, diameter 43 mm, height 39 mm; southern coast of Western Australia. The tubercles are small and set with short, thin spines. (B) Side view of test, diameter 33 mm; Leith, Tasmania. The interambulacra, and to a less degree the ambulacra, shows darker and lighter stripes, forming a zigzag pattern.

Amblypneustes leucoglobus Doederlein, 1914 (Fig. 4.138 B–D) Test: Diameter up to 50 mm. Apical system: Periproct tuberculated. Ambulacra: Pore pairs in oblique arcs of three. Ambulacral and interambulacral median zones appear to be bare, but mostly, they are set with very fine miliary tubercles. Spines: Primaries short, secondaries finer, and still shorter, miliaries very numerous. Color: The primary spines are dark olive with a lighter tip, the secondaries and the miliaries show a conspicuous white distal knob. The bare test is greenish gray with lighter pore zones, sometimes with a faint reddish brown tinge. Distribution: Southwest Australia from Esperance to Geraldton, 0 to 18 m deep. Amblypneustes ovum Lamarck, 1816 (Fig. 4.139 A) This species resembles very much to Amblypneustes elevatus but differs in having fewer and higher plates: Test: Thin and fragile, often egg-shaped; diameter up to 60 mm. Apical system: Periproct with tubercles. Ambulacra: Arcs of pore pairs erect, not forming three distinct vertical series. In ambulacra and interambulacra, the plates are high, the tubercles being rather distant, median zones rather bare.

Color: The spines are dark greenish, whitish, or brownish, not reddish; the bare test is greenish or brownish olive, pore zones darker or lighter. Distribution: Southern coast of Australia from the Bass Strait and Tasmania to the Spencer Gulf, littoral to a depth of 70 m. Amblypneustes pallidus Lamarck, 1816 (Fig. 4.139 B–D) Test: Diameter up to 45 mm. Apical system: Periproct non-tuberculated. Ambulacra with three vertical series of pore pairs. Median parts of ambulacra and interambulacra rather bare. Color: The bright colors distinguish A. pallidus from the other species of this genus. The primary spines are very variable, dark mauve with lilac or yellow distal ends, or greenish yellow at the base, more orange distally; the secondaries are mostly dark mauve to pinkish brown, the miliary spines are usually light lilac. The bare test is light or darker mauve, sometimes pinkish brown. Distribution: Along the southern coast of Australia from Port Willunga, South Australia, to the Houtman Abrolhos Islands, Western Australia, from the littoral zone to a depth of 137 m. Amblypneustes pulchellus H. L. Clark, 1928 The species is not well known. Test: The holotype has a diameter of 12.5 mm.

224 

 4.2 Subclass Euechinoidea Bronn, 1860

B

A

C

D

Fig. 4.138: (A) Amblypneustes formosus: side view of test, diameter of test 24 mm; Phillip Island, Victoria, Australia. Each plate has a dark lens-shaped spot below the primary tubercle. Some specimens may show a less conspicuous pattern. (B–D) Amblypneustes leucoglobus. (B) Side view of test, diameter 33 mm; Cockburn Sound, Western Australia. (C) Aboral side with spines, diameter 55 mm; Esperance Bay, Western Australia. ZMH. (D) Close-up of side: the miliary spines are densely distributed, they end distally in a conspicuous white knob. To the left, there are a light band of suckered tube feet.

Apical system: With non-tuberculated periproct. Ambulacra: Pore pairs in three vertical series. In ambulacra and interambulacra, the plates show a sparse but relatively even tuberculation; there are pits and grooves on the vertical sutures. Color: The cleaned test has plates with dark reddish brown centers and white borders. Distribution: Southeast coast of Australia and Tasmania, 0–2 m. Genus Erbechinus Jeannet in Lambert & Jeannet, 1935 The genus is monospecific. Erbechinus spectabilis differs from species of Temnotrema in the number of pits per

interambulacral plate: in Erbechinus, there are up to five; in Temnotrema, constantly 2. Erbechinus spectabilis Mortensen, 1904 (Fig. 4.140) Test: Low, slightly subconical, oral side flattened, scarcely sunken adorally, diameter up to 35 mm. Apical system: Tubercles on genital plates mainly along the inner part of the plates, the outer part being naked; gonopores distally in distinctly set off areas, sometimes breaking through edge of plate; ocular plates widely exsert, tuberculated, inner

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 225

B

D

Fig. 4.139: (A) Amblypneustes ovum. Side view of test, diameter 33 mm; Edithburg, South Australia. Length and height are almost equal. (B–D) Amblypneustes pallidus. (B) Side view with some remaining spines, test diameter 40 mm; Kangaroo Island, South Australia. Beside the primary tubercles, there is a series of smaller secondaries on each plate, accompanied by still smaller miliary tubercles. (C) Aboral side with spines and yellow tube feet, diameter of test 35 mm, height 35 mm; Albany, Western Australia. ZMH. The bright colors are typical for this species. (D) Side view with spines, test diameter 31 mm, height 32 mm; Albany, Western Australia.

suture with small pits; periproctal plates smooth and shining. Ambulacra: Pore pairs in steep arcs of three corresponding to each primary tubercle. Interambulacra: Vertical series of secondary tubercles on either side of the primaries. Tubercles: Very finely crenulated.

Peristome: Small; membrane naked, buccal plates smooth, notches quite faint. Spines: Primaries smooth and short, about 5 mm; sparse aborally, more numerous on oral side. Sculpture: More or less elongate pits along the horizontal sutures and medially; up to five at the ambitus, more or less fused toward apex and peristome.

226 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

E1

E2

E3

Fig. 4.140: Erbechinus spectabilis. (A) Side view of test, diameter 28 mm. Kei Island, Indonesia. ZMUC. (B) Side view of test. (C) Oral side of test: the peristomial membrane is excepting the buccal notches totally naked. (D) Aboral side with spines, diameter of test ca. 28 mm; Kei Island, Indonesia. ZMUC. The primary spines are slightly longer than the secondaries, their base being dark. (E1) Ambulacral plates. The pits are very conspicuous (solid black areas). (E2) Interambulacral plates. (E3) Ambulacral system. Scale: 2 mm (Mortensen 1943).

Color: The test and the spines may be whitish or dark grayish olive with all transitions, the base of the spines may also be dark. Distribution: This species has been recorded only from off the Kei Islands, Indonesia. Depth 230 to 250 m.

Genus Holopneustes L. Agassiz, 1841 This genus is very nearly related to Amblypneustes. It differs in having irregular series of ambulacral primary tubercles; in Amblypneustes, they are regular like a chain of pearls. Test: More or less globular.



Apical system: Dicyclic; gonopores positioned at the outer edge of genital plate; periproct subcircular. Ambulacra: More or less as wide as interambulacra; 3 pore pairs per plate; tubercles rather irregular, one primary to each 2 or 3 triads; numerous secondaries in pore zones and interporiferous zones. Interambulacra: Wide plates with small, rather sparse tubercles forming vertical and horizontal rows; median sutures with sharply incised depressions or pits. Peristome: Small, buccal notches shallow. Spines: Short and simple. There are three species of Holopneustes: Holopneustes inflatus Luetken, 1872. Southeast Australia. Holopneustes porosissimus L. Agassiz, 1846. South and Southwest Australia. Holopneustes purpurascens A. Agassiz, 1872. Southeast Australia and Tasmania. The three species differ mainly in the following features: Holopneustes inflatus: three vertical columns of pore pairs, fine tuberculation. Holopneustes porosissimus: irregular series of pore pairs; ambulacra wider than interambulacra. Holopneustes purpurascens: three vertical rows of pore pairs, rather coarse tuberculation. Literature: Morris 1995. Holopneustes inflatus Lütken, 1872 (Fig. 4.141) Test: Very variable, from low hemispherical to globular and even egg- or bottle-shaped; maximum diameter up to 70 mm. Apical system: Very small, with a more or less dense ring of tubercles around the periproct. Ambulacra: Generally not as wide as interambulacra, pore zones narrower than interporiferous zones; pore pairs in three more or less regular vertical series; primary tubercles only on each second or third plate, forming an irregular, vertical series. Interambulacra: Distinct horizontal row of tubercles on each plate, reaching the median space, not forming naked areas, in the whole the tuberculation is rather scarce. Peristome: Small, larger than apical disc, margin bending inward, with smooth, white edge; small, but distinct buccal notches. Spines: Uniformly short, 4–5 mm long, tapering distally, and ending in a small knob. Color: The range of color combinations is large. The spines may be light olive, yellowish, pinkish, or reddish; the bare test shows reddish to yellowish and mauve, more rarely greenish.

4.2.9 Order Camarodonta Jackson, 1912 

 227

Biology: Holopneustes inflatus often lives on large kelp fronds, holding the distal parts of the fronds tightly around itself, swinging with the waves. The species is also found in sea grass. It prefers more sheltered water than Holopneustes purpurascens. Distribution: The species is restricted to southeast Australia and Tasmania. It is known from the littoral zone down to a depth of 25 m. Holopneustes porosissimus L. Agassiz, 1846 (Fig. 4.136 B, 4.142) Test: Very variable, globular, or high subconical; only slightly flattened on the oral side; usually not higher than wide; maximum diameter 70 mm. Apical system: Very small, often elevated; genital and ocular plates densely tuberculated; periproctal plates small and very numerous. Ambulacra: Much broader than interambulacra, pore zones very wide, two fairly regular vertical series of pore pairs at the outer margins, the space between them filled with very irregularly arranged pore pairs and scattered tubercles; tubercles in interporiferous zone very irregularly arranged as well (already visible in small specimens, which have still three distinct vertical series of pore pairs). Interambulacra: Narrow, primary tubercles form regular, dense series at the outer edge of plates, in ambital region some horizontal rows with secondaries of same size, the other secondaries smaller and irregular; the remainder of plates densely covered with small miliary tubercles, leaving no distinct, naked median space. Peristome: Larger than apical disc, but still small; peristomial margin of test bending inward with a white, smooth edge; membrane naked, pairs of buccal plates widely separated, buccal notches small. Spines: Uniformly short, rather robust, ending distally in a distinct rounded knob. Color: The primary spines are usually greenish at the base and bright red in the distal part, especially the knob. The secondary spines are uniformly greenish. The bare test is mostly a grayish olive with darker zones along the midlines of the areas. But occasionally, there are specimens with beautiful purple tests or with radiating patterns in olive and purplish; the spines of these are also purplish. The range of variation is very large. Biology: Holopneustes porosissimus is reported to live on large kelp, holding the “leaves” tightly around its test, lying there as in a cradle and swinging with the waves. The numerous aboral pore pairs set with tube feet, and the very short spines are adapted to this special habitat. The

228 

A

C

 4.2 Subclass Euechinoidea Bronn, 1860

B

D

E

Fig. 4.141: Holopneustes inflatus. (A) Aboral side of test, diameter 56 mm, height 49 mm; New South Wales, Australia. The ambulacra are narrower than the interambulacra. (B) Side view of test: the tuberculation is fine. (C) Several specimens; diameter of the specimen in the center reaches 32 mm; New South Wales, Australia. The variation of color of the test is very large, and the spines also show different colors. (D) Oral side of test, diameter 52 mm, height 51 mm; Tasmania. The peristome is small. (E) Close-up of interambulacrum and ambulacrum in the center: only every second or third ambulacral plate is set with a primary tubercle, the pore pairs are arranged in three distinct vertical series. Scale: 10 mm.

4.2.9 Order Camarodonta Jackson, 1912 



A

 229

B

C D

Fig. 4.142: Holopneustes porosissimus. (A) Half a column of ambulacral plates: the interporiferous zone is set with numerous irregularly arranged pore pairs bordered by two fairly regular series. Scale: 1 mm (Mortensen 1943). (B) Aboral side of test, diameter 52 mm; Fremantle, Western Australia. The ambulacra (marked as A) are much broader than the interambulacra (marked as IA) at the ambitus. (C) Side view of test, diameter 42 mm, height 38 mm; southwest Australia. The median zones look bare. (D) Side view with spines; test diameter 47.5 mm, height 48 mm; Hamelyn Bay, Western Australia (coll. HF). The spines are bright red. Often only the distal thickened knob is red.

animal is likely to come down at night to feed on the alga Corallina. Distribution: This species is found only in Australia from the Bass Strait, Victoria, to the Houtman Abrolhos Islands, Western Australia, settling from the shore to a depth of 5 m. Holopneustes purpurascens A. Agassiz, 1872 (Fig. 4.143) This species is similar to the other species of Holopneustes. Ambulacra: The median column of the pore pairs may be slightly irregular, but well defined, as in Holopneustes inflatus, or the pore zone forms a broad irregular band of

pore pairs as in H. porosissimus. The arrangement of the primary tubercles may be as irregular as in H. porosissimus. Generally, Holopneustes purpurascens differs by its more robust test and coarser tubercles, which cover most of the height of the plates. Furthermore, the primary and the secondary tubercles are subequal. There is a more or less conspicuous bare space at the median line. The color of the test is not reliable for distinguishing the species, although Holopneustes purpurascens is generally a dull grayish, brownish, or mauve, but sometimes also reddish, pink, or orange. The spines are mostly pale lavender, gray, or brownish.

230 

 4.2 Subclass Euechinoidea Bronn, 1860

B

A

C

D

E

Fig. 4.143: Holopneustes purpurascens. (A) Side view with spines, diameter 68 mm, height 72 mm; Sydney, Australia. The spines are rather coarse. (B) Side view of test, diameter 50 mm; New South Wales, Australia. The pore pairs form three regular series. (C) Aboral side of test, diameter 61 mm; Sydney, Australia. Near the apical system, the interambulacra are extremely narrow, leaving more width for the strongly developed pore zones in the broad ambulacra. (D) Oral side: the buccal notches are small. (E) Close-up of ambital ambulacrum: the pore zones form a broad band of irregularly distributed pore pairs. Scale: 15 mm.

Biology: Generally, this species lives in areas with stronger wave motion having coarser tubercles set with thicker spines. Holopneustes inflatus prefers more sheltered water and H. porosissimus lives in large kelp. Morris (1995) described the abbreviated development in this species. The juveniles do not run through a larval stage. Distribution: This species is restricted to the southeast coast of Australia from Richmond, New South Wales, to South Australia, including Tasmania, living from the shore to a depth of 8 m. Genus Mespilia Desor, 1846 The monospecific genus is characterized by conspicuously dark and sharply limited naked areas in ambulacra and

interambulacra. In specimens from Japan, these zones are less distinct. Mespilia globulus Linné, 1758 (Fig. 4.144) Test: Almost globular, slightly flattened on the oral side; circumference round or pentagonal; diameter may reach 50 mm. Apical system: Rather small, genital plates densely covered by small tubercles except on their distal part, gonopores small; all ocular plates widely exsert; madreporite often enlarged and elevated. Ambulacra: Rather broad, two distinct vertical series of pore pairs; one regular row of small primary tubercles near the inner pore pairs, some more series of secondaries of

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 231

B

D

Fig. 4.144: Mespilia globulus. (A) Aboral side of test, diameter 38 mm; Negros, Philippines. The black, bare median zones in the interambulacra are sharply separated from the tuberculated zones. (B) Underwater photo by H. and I. Rauch. Philippines. (C) Aboral side of test, diameter 24 mm; Shimizu, Central Japan. The median zones in the ambulacra are whitish, they may also be brown. (D) Aboral side with spines, diameter 25 mm; Shimizu, Japan. The bare zones are greenish and not sharply separated from the tuberculated areas.

same size around the ambitus and on the oral side; median part mostly naked; in other specimens, it may be less distinct; small pits along the edges of the sutures. Interambulacra: Very distinct naked median zones, small pits along the edges of the sutures, bordered by more or less regular series of small tubercles, only near the peristome the entire plates are covered by horizontal series of slightly larger tubercles. The median zones,

especially in the interambulacra, appear to be naked but effectively they are densely covered by minute pedicellariae. Peristome: Small, distinctly less than one third of test diameter; buccal notches shallow; membrane naked. Spines: On ambulacra and interambulacra, uniformly short and thin, longer and thicker on the oral side.

232 

 4.2 Subclass Euechinoidea Bronn, 1860

Color: The tuberculated part of the test is mostly reddish, the tubercles themselves are whitish. The naked zones in ambulacra and interambulacra strongly contrast in being dark olive, black, or even blue. The test may also be olive or greenish with no red at all, or the naked zones may be whitish, especially on the oral side. The spines are banded in whitish with green or red. Biology: Mespilia globulus lives in the littoral zone, found under stones or on coral reefs. It is known also from a depth of 60  m. The animal often camouflages itself against direct light or predators by holding pieces of shells or algae over the test. Distribution: This species occurs from Malaysia to Japan, from the northern coast of Australia eastward to the Tonga Islands. Literature: Shigei 1986. Genus Microcyphus L. Agassiz in L. Agassiz & Desor, 1846 This genus is characterized by having conspicuous, more or less zigzag shaped, naked zones in the interambulacra and occasionally in the ambulacra as well. The sculpture is poorly defined with small pits or weak outlines of sutures. Test: More or less high, oral side slightly flattened; outline round or rounded pentagonal. Apical system: Rather small; ocular plates exsert, gonopores at the outer edge of the genital plates; region may be offset; madreporic plate hardly differentiated in size from the other genital plates. Ambulacra: Pore zones narrow, pore pairs in steep arcs of three. Interambulacra: More or less broad or zigzag-shaped naked areas; oral side densely tuberculated. Peristome: Small; buccal plates naked except small buccal plates; buccal notches shallow. Spines: Short and simple, tapering to a point. Ten species are distributed in the Indo-Pacific, from the east coast of Africa to Japan and Australia: Microcyphus annulatus Mortensen, 1904. Southern ­Australia and Tasmania.

Microcyphus ceylanicus, Mortensen 1942. Ceylon and the Andamans. Microcyphus compsus H. L. Clark, 1912. Southern Australia and Tasmania. Microcyphus excentricus Mortensen, 1940. Philippines. Microcyphus keiensis Mortensen, 1942. Kei Islands, Indonesia. Microcyphus maculatus A. Agassiz, 1846. Northeast Australia and Mauritius. Microcyphus olivaceus Döderlein, 1885. Japanese waters. Microcyphus pulchellus H. L. Clark, 1928. South Australia. Microcyphus rousseaui L. Agassiz, 1846. East Africa and Red Sea. Microcyphus zigzag L. Agassiz, 1846. Southern Australia and Tasmania. Microcyphus annulatus Mortensen, 1904 (Fig. 4.145 A3, B, C) Test: Globular and very thick; maximum diameter 20 mm. Apical system: Gonopores at the outer edge of the genital plates; ocular plates small and exsert. Ambulacra: Oblique arcs of 3 pore pairs; median zone with a naked zigzag band. Interambulacra: Very distinctly zigzag shaped, naked bands along the median suture. Tubercles: Crenulated and rather coarse. Peristome: Smaller than apical system. Spines: About 3 mm in length. Color: In living specimens, the spines are greenish at the base, reddish in the middle and white at the tip. The bare test is a more or less dark brown distinctly contrasting to the white tubercles. The apical plates are also dark brown with white tubercles. Distribution: This species is known in southeast Australia from Victoria to the St. Vincent Gulf, South Australia, and in Tasmania at depths between 5 and 80 m. Microcyphus ceylanicus Mortensen, 1942 (Fig. 4.145 F, G) Test: Low, slightly flattened orally; diameter may reach 27 mm. Apical system: Plates with several tubercles concentrated on the inner half of the genital plates; large gonopores in distal edge; ocular plates with a single larger tubercle.

▸ Fig. 4.145: (A) Three species of Microcyphus from southern Australia: (1) Microcyphus zigzag, (2) Microcyphus compsus, (3) Microcyphus annulatus (photo by A. Miskelly). (B, C) Microcyphus annulatus. (B) Pattern of the bare median zones in ambulacra and interambulacra: the band is broad and there are rather few plates in one column. (C) Diagram of interambulacral plate. (D, E) Microcyphus zigzag. (D) Pattern of the bare zones: the band is narrow and there are more plates in one column than in M. annulatus. (E) Diagram of interambulacral plate. Bare zones shaded. (F, G) Microcyphus ceylanicus. (F) Apical disc: the gonopores open in the distal edge of the genital plates. (G) Ambulacral plates: there is a distinct naked median area. (H, I) Microcyphus excentricus. (H) Adoral part of interambulacrum: pits are only developed on the oral side. (I) Ambulacral plates. Scale: 3 mm (Mortensen 1943).

4.2.9 Order Camarodonta Jackson, 1912 



A

B

E

H

C

D

F

I

G

 233

234 

 4.2 Subclass Euechinoidea Bronn, 1860

Ambulacra: Pore pairs in distinct double series, one formed by the pore pairs of the upper and lower plate component, the other formed by the middle pore pairs; distinct naked area along the median line extending more or less wide adorally. Interambulacra: Tubercles irregularly arranged, primaries hardly discernible; sharply defined naked areas along the median suture, also below the ambitus; angular pits in triple sutures. Peristome: Small plates around the mouth, close-set buccal plates, distal part of membrane naked; buccal notches very shallow, but sharp. Spines: Short, not longer than 4  mm, adorally slightly flattened and widened. Color: The test is light olive green, the naked interambulacral areas are marked by a dark zigzag line along the median suture. The spines are banded in red brown and whitish. Distribution: This species is restricted to Sri Lanka and the Andaman Islands living in the littoral. Microcyphus compsus H. L. Clark, 1912 (Fig. 4.145 A2) Test: Globular and very strong; diameter may reach 23 mm. Apical system: Smaller than peristome. Ambulacra: Steeply oblique arc of 3 pore pairs per plate, naked median zigzag band. Interambulacra: Well tuberculated with primary, secondary, and miliary tubercles leaving a distinct naked zigzag band along the median area; three larger tubercles in a row discernible. Sculpture as weak outline of sutures. Peristome: Hardly concave at the edge. Spines: Not recorded. Distribution: Restricted to southeastern Australia from Victoria, the Bass Strait and Tasmania to the Spencer Gulf, South Australia. Bathymetric range 40 to 235 m. Microcyphus excentricus Mortensen, 1940 (Fig. 4.145 H, I) Test: Pentagonal, interambulacra slightly inflated, flattened above and below. Apical system: Distinctly elongated. Ambulacra: Distinct naked median areas; pits on oral side; regular series of primary tubercles. Interambulacra: Well-limited broad naked areas, beginning near the peristome; tubercles not forming distinct series, neither vertically nor horizontally, primary and secondary tubercles not distinguishable; small pits on oral side. Peristome: Relatively large, buccal notches small. No spine described.

Color: The naked areas are reddish, a little darker along the sutures. A dark olive green band marks the border to the whitish, tuberculated parts of the plates. Distribution: Philippines. Microcyphus keiensis Mortensen, 1942 (Fig. 4.146) Test: Regularly hemispherical, circumference subpentagonal; maximum diameter 34 mm. Apical system: Tubercles on genital plates restricted to the inner part; pores sunken; distinct pits in triple sutures. Ambulacra: Pore pairs in arcs of three; primary tubercles in regular vertical series close to the pores, a parallel row of secondaries reach half the upper side; naked median space narrow and not well limited; small pits in triple junctions. Interambulacra: 4–6 larger tubercles in a regular horizontal series at the ambitus, primaries slightly larger than secondaries; broad lozenge-shaped naked areas, not well defined; on the oral side indistinct, narrow vertical depressions crossing the sutures. Peristome: Membrane naked except for the buccal plates and some small platelets at the edge of the mouth. Spines: Primaries not longer than 5 mm. Color: The naked median areas are light olive green, brown green, or purplish green to purple, toward the sides becoming darker. The spines show usually 3–4 narrow bright red bands. Distribution: Philippines and Malayan Archipelago. Depth 50 to 100 m. Microcyphus maculatus L. Agassiz, 1846 (Fig. 4.147 A, B) Test: Thick; maximum diameter up to 30 mm. Ambulacra: Pore pairs in two vertical series; naked areas narrow and with distinct pits in the triple sutures. Interambulacra: Pits in the broad naked areas; primary tubercles in horizontal series occur only on oral side. Tuberculation: In ambulacra, interambulacra, and apical plates rather coarse. Peristome: Large. Color: The test is reddish and the spines are greenish. Distribution: This species has a discontinuous range, being known from the Great Barrier Reef in northeast Australia and from Mauritius. Microcyphus olivaceus Döderlein, 1885 (Fig. 4.147 C, D) Test: Hemispherical and in outline round; diameter may reach about 30 mm. Apical system: Tubercles on genital plates confined to the inner edge, large pores in the distal edge; in younger specimens, the low outer part of the ocular plates is sharply limited against the raised inner part.

4.2.9 Order Camarodonta Jackson, 1912 



A1

A2

B

 235

A3

C

Fig. 4.146: Microcyphus keiensis (A1) Aboral ambulacral plates. (A2) Aboral interambulacral plates. Scale: 3 mm. (A3) Apical system. Scale: 4 mm (Mortensen 1943). (B) Side view of test, diameter 25 mm; Kei Island. ZMUC ECH 206. The primary tubercles are a little larger than the secondaries forming a distinct row. (C) Aboral side of test, diameter 22 mm; Balut Island, Philippines (photo by Bas van der Steld).

Ambulacra: Pore pairs in steep arcs of three; regular vertical series of primary tubercles close to the pores, parallel series of secondaries reaching almost up to the apical disc. Interambulacra: Distinct primary tubercles gradually decreasing in size from the adoral edge to the apical system; with the slightly smaller secondaries forming a row of 3–4 larger tubercles per plate; naked median areas not sharply defined; angular pits in triple sutures only in young specimens. Peristome: Naked except closely joined buccal plates, notches small and sharp. Spines: Short, about 5 mm. Color: The spines are greenish at the base, with brown red bands and a whitish tip. The shorter aboral spines

are not banded. The test is greenish olive or bright green, the ambulacra are a little lighter with whitish pore zones. Often, the apical plates are dark. Distribution: The species is restricted to Japanese waters from Sagami Bay to the Goto Islands. Bathymetric range 70 to 700 m. Microcyphus pulchellus H. L. Clark, 1928 It seems that this species is unusual in having much more ambulacral plates than the other species. Mortensen reported for M. pulchellus 27–28 plates at a test diameter of 12.5  mm, but for specimens of M. zigzag, M. compsus, and M. annulatus of corresponding size, only 14–18 plates. Interambulacra: 3 larger tubercles in horizontal series on interambulacras.

236 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

Fig. 4.147: (A, B) Microcyphus maculatus. (A) Side view of test with some remaining spines, diameter 25 mm, height 19 mm; Mauritius. ZMUC. The naked interambulacral areas are broad. (B) Oral side: the test is pentagonal the peristome being relatively large. (C, D) Microcyphus olivaceus. (C) Aboral side of test, diameter 27 mm; Sagami Bay, Japan. ZMUC. The species has a peculiar apical disc: the distal parts of the plates are distinctly set off as lower areas. The gonopores have developed papillae being surrounded by a rim. (D) Side view of test.

Color: Margins of plates white, center red brown, lowermost plates wholly reddish brown. Distribution: South Australia. Microcyphus rousseaui L. Agassiz in L. Agassiz & Desor, 1846 (Fig. 4. 148) Median naked areas whitish, toward the outer part increasingly purplish. Test: High hemispherical, slightly flattened below; generally rounded pentagonal, interambulacra faintly sunken; test diameter up to 50 mm. Apical system: More or less densely covered by tubercles, madreporite slightly enlarged; ocular plates small and exsert; gonopores at outer edge of genital plates.

Ambulacra: Narrow; pores in two vertical series, 2 pore pairs in the inner row, 1 pore pair in the outer one; primary and secondary tubercles of same size; one row rather regularly alternating with the outer pore pair, the interporiferous zone with irregularly arranged tubercles; median areas not naked. Interambulacra: Tuberculated part of plates densely and irregularly covered with tubercles, which decrease toward the median line; naked part of plates exceedingly variable in size and shape from broad spaces along the vertical and horizontal sutures to rather narrow and inconspicuous zones; oral plates entirely tuberculated. Peristome: Naked; larger than apical system; buccal notches broad and shallow.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 237

B

E

D

Fig. 4.148: Microcyphus rousseaui. (A) Aboral side of test, diameter 41 mm; Hurghada; Egypt, Red Sea. The test is rounded pentagonal, pointed at the narrow ambulacra. (B) Close-up of interambulacrum: the plates show a densely tuberculated part sharply separated from areas seemingly naked, but in life, they are set with fine pedicellariae. Scale: 9 mm. (C) Aboral side of test, diameter 34 mm; Jemen. The extent of the naked areas is highly variable. (D) Aboral side with spines, diameter of test 37 mm; Gulf of Suez; Red Sea. ZMH. The short spines are tipped in white. (E) Oral side with spines: the peristomial membrane is thick and naked.

238 

 4.2 Subclass Euechinoidea Bronn, 1860

Spines: Of uniform size, simply cylindrical, terminating in a central thorn; spines of the oral side scarcely flattened. Color: The spines are reddish brown with a white tip, sometimes faintly banded toward the distal end. The tube feet are dark brownish with a white sucking disc. In life, the naked parts in the interambulacra are light at the sutures, gradually turning darker to purplish away from the outer edges. On the bare test, the tuberculated zones are light greenish olive; the pore zones sometimes purplish. Biology: Microcyphus rousseaui lives in reefs, probably feeding on the lower dead parts of the corals. The ecological advantage of the naked zones, which are in life densely covered with fine pedicellariae, is not known. Perhaps, these bright areas might irritate possible predators or camouflage the compact shape of the test. Distribution: The species is found in the Red Sea, the East African coast southward to Mozambique, and around Madagascar, restricted to the littoral zone. Microcyphus zigzag L. Agassiz in L. Agassiz & Desor, 1846 (Fig. 4.145 A1, D, E) Test: Globular and very thick; maximum diameter 31 mm. Apical system: Gonopores open in the bare interambulacra. Ambulacra: Pore pairs in oblique arcs of three; narrow bare zigzag band along median suture. Interambulacra: Narrow bare zigzag band along the vertical median suture, expanding along each horizontal suture; plates relatively numerous; 4–6 larger tubercles in a horizontal row. Peristome: Small, approximately as large as apical system. Spines: Primary spines about 4 mm long, secondaries distally with thickened knob. Color: In life, the primary spines are orange red and the secondary spines pale greenish with orange toward the distal end. The bare test is dark reddish brown at the plate sutures, the pore zones are more pinkish cream. Distribution: The species is restricted to southern Australia from Victoria to the Gulf St. Vincent and around Tasmania from the shore to a depth of 40 m. Genus Opechinus Desor, 1856 Test: Regularly hemispherical, slightly flattened below; tubercles usually crenulated. Apical system: Genital plates with a few tubercles, ocular plates widely exsert, carrying only a single larger tubercle, periproctal plates smooth. Ambulacra: Pore pairs forming a straight series.

Interambulacra: One primary tubercle on the middle of the plate, secondaries on either side and above. Sculpture: Alternating sutural depressions in ambulacra, in interambulacra widened below the primary tubercles, additional small pits at the primary tubercles; depressions in the apical system. Peristome: Membrane naked except for the rather small buccal plates; buccal notches inconspicuous. Spines: Short, scarcely reaching one third of test diameter. The two extant species are very similar: Opechinus albus Mortensen, 1942. Kei Islands, Indonesia. Opechinus variabilis Döderlein, 1885. Japan. Opechinus albus Mortensen, 1942 (Fig. 4.149 A, B) Main characteristics of the genus. The diameter may reach 15 mm. Apical disc: Sharp-edged depressions at the inner end of the ocular plates, the distal parts of ocular and genital plates, sharply set off. Color: Test and spines are pure white or uniformly light green beige. Distribution: Mortensen (1943) reported this species only from the Kei Islands, Indonesia. Bathymetric range 345 to 385 m. Remark: On the whole, the sculpture of Opechinus albus is more deeply depressed than in Opechinus variabilis. Opechinus variabilis Döderlein, 1885 (Fig. 4.149 C, D) Main characteristics of the genus. Diameter may reach 16 mm. Apical system: Genital plates with 1–3 tubercles, otherwise totally bare, ocular plates with 1 tubercle plus several miliaries; relatively shallow depressions in the triple sutures. Color: There is a conspicuous white spot in the interambulacra. The test in the whole is dark olive brown the ambulacra being lighter. The spines show a greenish olive, dark at the base, light toward the tip. Distribution: The species occurs in Japanese waters from Sagami Bay to the Goto Islands, at depths of 100 to 550 m. Genus Paratrema Koehler, 1927 The monospecific genus is characterized by having only five single small buccal plates associated with five buccal tube feet, not five pairs of buccal plates as other temnopleuroid echinoids. Paratrema doederleini Mortensen, 1904 (Fig. 4.150) Test: Thick, regularly hemispherical, diameter of test up to 12 mm.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 239

B

D

Fig. 4.149: (A, B) Opechinus albus. (A) Side view of test, diameter 15 mm; Kei Islands, Indonesia. ZMUC. (B) Aboral side with some remaining spines, test diameter 13 mm; Kei Islands, Indonesia. ZMUC. There is a deep, sharply defined pit in the triple suture below each ocular plate. (C, D) Opechinus variabilis. Side view of test, diameter 12 mm; Sagami-Bay, Japan. ZMUC. There is a white spot in each interambulacrum. (D) Aboral side with spines, diameter of test 14 mm; Sagami Bay, Japan. ZMUC.

Apical system: Distal part of the genital plates markedly set off, inner part with a row of large tubercles along the periproctal edge, ocular plates with a single large tubercle; periproct covered by quite small plates lacking a distinct suranal plate. Ambulacra: Regular series of primary tubercles, irregular inner series of smaller secondaries; pore pairs in quite steep arcs of three; elongate grooves in the horizontal sutures of the median area and the outer side. Interambulacra: Regular series of primary tubercles, parallel series of smaller secondaries; deep depressions at the median and the adradial suture. Peristome: Naked, five small buccal plates. Spines: Short and smooth.

Color: The test is bright green along the midlines, lighter green on poriferous zones, and interambulacral tubercles, adorally more white. Distribution: Paratrema doederleini is known from Hong Kong, the Gulf of Siam, the Andamans, and the Java Sea, also from Samoa and Fiji Islands. Bathymetric range 10 to 20 m. Remark: Paratrema looks very much like some species of Temnotrema. It differs in having only five buccal plates, Temnotrema has five pairs thus ten. Genus Printechinus Koehler, 1927 The genus is characterized by narrow, more or less vertical depressions crossing the horizontal sutures between the primary tubercles.

240 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

Fig. 4.150: Paratrema doederleini. (A) Aboral side of test, diameter 12 mm; Singapore. ZMUC. The periproct is covered by small plates without a larger suranal plate. (B) Oral side: the membrane is totally naked except 5 lone small buccal plates, each carrying a tube foot (one buccal plate is marked by an arrow).

Test: Moderately thick. Apical system: Ocular plates exsert, gonopores at the outer edge of plates, ring of larger tubercles encircling the periproct, otherwise almost bare; irregular periproctal plates; distal edge of ocular plates with pores offset. Ambulacra: Pore pairs in a straight line, a single crenulated primary tubercle per plate. Interambulacra: A crenulated primary tubercle on every plate; vertical depressions. Spines: Short. Two extant species are included in the genus: Printechinus impressus Koehler, 1927, Andaman Sea. Printechinus viridis Mortensen, 1942, Sumatra. Printechinus impressus Koehler, 1927 (Fig. 4.151 A, B) Test: Hemispherical, flattened below, diameter may reach 25 mm. Apical system: Dicyclic with few tubercles more or less confined to the inner edge; gonopores at the distal edge, anal opening subcentral. Ambulacra: Pore pairs almost in a straight line, each plate set with a crenulate primary and a secondary tubercle, small depressions near the tubercles, median zone naked; pits in the triple sutures. Interambulacra: Each plate set with one crenulate primary tubercle and a few scattered secondaries; on the oral side, distinct horizontal series of larger tubercles;

conspicuous vertical depressions between the primary tubercles, small pits in the triple sutures continuing onto the oral side; median zone naked. Peristome: Naked, buccal notches small and shallow. Spines: Short. Color: The test is reddish, the depressions are very conspicuously darker. On the oral side the spines are banded in green and red, aborally they show only a red tip. Distribution: Andaman Sea, Indian Ocean. Bathymetric range 110 to 135 m. Printechinus viridis Mortensen, 1942 (Fig. 4.151 C–E) Test: Subspherical, underside flattened; diameter 15 mm. Apical system: Genital pores very large breaking through the distal edge of the genital plate, some larger tubercles forming a ring along the inner edge; a few tubercles on the exsert ocular plates. Ambulacra: Broad, about two thirds of interambulacra; pore pairs in a straight line; one primary tubercle per plate accompanied by a smaller secondary one and two still smaller ones above; small vertical depressions near the primary tubercles and in the triple sutures. Interambulacra: Each plate set with a rather small primary tubercle and several smaller secondaries, no naked median area; 4 to 5 sutural depressions, one to two adjoining the primary tubercle.

4.2.9 Order Camarodonta Jackson, 1912 



A

 241

B

D

C E

Fig. 4.151: (A, B) Printechinus impressus. (A) Aboral side of test, diameter 14 mm; Andaman Sea. ZMUC. (B) Side view of test. (C–E) Printechinus viridis. (C) Aboral side of test, diameter of test 15 mm; Sumatra, Indonesia. ZMUC ECH 310. The female has very large gonopores. (D) Side view. (E) Oral side. The peristomial membrane is totally naked except the pairs of buccal plates.

Peristome: Entirely naked except of paired buccal plates, buccal notches inconspicuous. Spines: Very short and slender, hardly exceeding 2 mm. Color: The test is dark green in the interambulacra, lighter green in the ambulacra, with a small white ambital spot in each area. The spines are a very light green and not banded.

Distribution: Mortensen recorded a single specimen found east of Sumatra, Oleleh Strait; no depth was stated. Genus Pseudechinus Mortensen, 1903 The members of this genus are characterized by enlarged suranal plates and eccentric anal openings.

242 

 4.2 Subclass Euechinoidea Bronn, 1860

Test: Low hemispherical to subconical, outline round, oral side flattened. Apical system: Hemicyclic (ocular plate I insert) or dicyclic; each genital plate with distal gonopores and one large tubercle; periproctal opening eccentric, usually with distinct large suranal plate. Ambulacra: Pore pairs in arcs of three, more or less offset; primary tubercle and slightly smaller secondary one on ambital plates. Interambulacra: One primary tubercle and flanking secondaries ambitally. Tubercles small and not crenulated. The test is not sculptured. Usually, the adult specimens of the genus lack angular pits, which, however, are still present in juveniles. Peristome: Slightly sunken, naked except for paired buccal plates, notches inconspicuous. Spines: Short and simple. The genus consists of many Recent and fossil species, most of them are endemic to New Zealand: Pseudechinus albocinctus Hutton, 1872. New Zealand.

A

Pseudechinus flemingi Fell, 1958. New Zealand. Pseudechinus grossularia Studer, 1880. New Zealand. Pseudechinus hesperus H. L. Clark, 1938. Australia. Pseudechinus huttoni Benham, 1908. New Zealand. Pseudechinus magellanicus Philippi, 1857. Southern South America and Subantarctica. Pseudechinus marionis Mortensen, 1936. Marion Island, Indian Ocean. Pseudechinus notius H. L. Clark, 1916. Australia. Pseudechinus novaezealandiae Mortensen, 1921. New Zealand. Pseudechinus sanctipauli Dollfus, 1946. Saint Paul Island, Indian Ocean. Pseudechinus variegatus Mortensen, 1921. New Zealand. Literature: Mortensen 1921; McKnight 1969, Tracey et al. 2011. Pseudechinus albocinctus Hutton, 1872 (Fig. 4.152 A, B) Test: Diameter up to 40 mm. Apical system: Madreporite enlarged, ocular plates I and II generally insert.

B

C

Fig. 4.152: (A, B) Pseudechinus albocinctus. (A) Aboral side of test, diameter 27 mm; South Island, New Zealand. The test is densely tuberculated, the primary tubercles are distinctly larger than the secondaries. (B) Oral side of test. (C) Pseudechinus huttoni. Aboral side of test, apical plates lost, diameter 38 mm; South Island, New Zealand. The tubercles are sparse, increasing in number toward the ambitus with the addition of thin rows of secondary tubercles.



Ambulacra: Two narrow bands of pore pairs in arcs of three, two series of regular primary tubercles. Interambulacra: Distinct large primary tubercle on each plate, weakly crenulated; additional secondaries at ambitus and on oral side; numerous miliary tubercles. Peristome: Depressed, buccal notches shallow, but distinct. Spines: Do not exceed 12 mm. Color: The test is pinkish to grayish, the spines are pinkish to dull reddish brown with a distinct white tip. Distribution: This species is endemic to New Zealand, mainly around the South Island reaching north to Wanganui and Wellington Harbour, living from the shore to a depth of 145 m. Pseudechinus flemingi Fell, 1958 Test: Hemispherical, orally flattened, holotype 52 mm in diameter. Apical system: Ocular plates all exsert. Ambulacra: Primary tubercles contiguous throughout; adradially much smaller secondaries forming a vertical series. Interambulacra: Primary tubercles not contiguous; enlarged secondary tubercles usually in horizontal rows. Sculpture: Weak admedian grooves on aboral interambulacra and shallow ridges forming a radiating pattern around the interambulacral primary tubercles being set by rows of miliary tubercles; on immature specimens, these patterns occur also on ambulacra, but disappear later. Spines: Primaries in length up to equal to test diameter, very densely distributed. Color: The spines are brilliant orange red or deep salmon red with white tips. The denuded test is a rose red with paler rose tubercles. Distribution: Endemic to New Zealand: around the Chatham Islands and off Otago. Bathymetric range about 90 to 600 m. Remark: This species differs from Pseudechinus albocinctus by its much longer and more brightly colored spines. Pseudechinus grossularia Studer, 1880 Test: Globular, oral side very slightly flattened, plates thin and smooth; holotype with a length of 20 mm. Apical system: Ocular plate I insert; all plates with a single tubercle. Ambulacra: Pore pairs in steep arc. Interambulacra: Sparsely tuberculated, only one or two secondary tubercles beside primaries; orally more densely arranged.

4.2.9 Order Camarodonta Jackson, 1912 

 243

Spines: Short, probably only 4–5 mm in length. Color: The test is white, the primary tubercles reddish orange. The primary spines are red basally, then intensely green gradually turning white. Occurrence: Three Kings Island, northern New Zealand. Depth 179 m. Pseudechinus hesperus H. L. Clark, 1938 Small form, mature holotype with a length of 7.5  mm (Mortensen 1943). The test is lavender brown, the spines not banded. Occurrence: The holotype was found in the littoral of Rottnest Island, Western Australia. Pseudechinus huttoni Benham, 1908 (Fig. 4.152 C) Test: Hemispherical or slightly conical; diameter up to 70 mm. Apical system: Ocular plate I broadly insert; suranal plate not conspicuous among periproctal plating. Ambulacra: Narrow, pore pairs in erect arcs of three. In ambulacra and interambulacra plates high, tubercles small and sparse, toward ambitus thin rows of secondary tubercles, up to four per plate at ambitus, over the oral side more densely arranged. Peristome: Depressed. Spines: Short and stout. Color: In life, the test is pinkish or totally white; in dried specimens, it becomes straw colored. The spines may be reddish, green, or white as well. Distribution: This species is endemic to New Zealand, mainly around the South Island, known from the shore to a depth of about 550 m. Pseudechinus magellanicus Philippi, 1857 (Fig. 4.153 A, B) Test: Small to medium in size, hemispherical; maximum diameter 40 mm. Apical system: Relatively large, ocular plate I usually insert; distinct suranal plate. Ambulacra and interambulacra: Densely tuberculated, primary tubercles distinctly larger than secondaries, many scattered miliary tubercles. Spines: Short. Color: The spines are brownish, the distal part lighter than the base. The bare test is a pale purplish brown with lighter pore zones. Distribution: This species is found from the mouth of the La Plata, Argentina, round the coasts of South America to Puerto Montt, southern Chile, off the Falkland Islands, the Antarctic Peninsula, and off the New Amsterdam Island in the southern Indian Ocean, living from the littoral zone to a depth of 820 m.

244 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

Fig. 4.153: (A, B) Pseudechinus magellanicus. (A) Aboral side of test, diameter 31 mm; Ushuaia, Fireland, Argentina. The periproct is covered by a large suranal plate and some other plates of slightly less size. (B) Aboral side with spines, diameter of test 32 mm; Ushuaia, Argentina. The spines are short and densely distributed. (C, D) Pseudechinus novaezealandiae. (C) Aboral side of test, diameter 46 mm; South Island, New Zealand. The tuberculation is rather coarse. (D) Oral side: the buccal notches are shallow.

Pseudechinus marionis Mortensen, 1936 Test: Diameter may reach 27 mm. Apical system: Ocular plate I insert, often also O II and O V; very conspicuous suranal plate, separated from the edge; all apical plates distally naked. Interambulacra: Primary tubercles confluent and larger than in ambulacra; areoles appear to be deeper. Spines: Slender, not longer than 10 mm. Color: The test is greenish or white, the spines also white.

Occurrence: The species is endemic to the Marion Island, southern Indian Ocean. Bathymetric range 100 to 2,950 m deep. Pseudechinus notius H. L. Clark, 1916 The test plates appear to be thick and rough, but they are not sculptured. Distribution: Endemic to southeast Australia in Victoria and Tasmania. Bathymetric range 36 to 244 m.



Pseudechinus novaezealandiae Mortensen, 1921 (Fig. 4.153 C, D) Test: Hemispherical with flattened and slightly depressed underside; maximum diameter 50 mm. Apical system: Suranal plate relatively small. Spines: Short and coarse. Color: The test is dull green to grayish green, sometimes light brown with darker median zones. The spines are dull green with white tips or uniformly gray. Distribution: This species is found around the South Island of New Zealand, and off Stewart, Campbell, and Macquarie Islands from the shore to a depth of 306 m. Pseudechinus sanctipauli Dollfus, 1946 Occurrence: Endemic to Saint Paul Island, southern Indian Ocean. Pseudechinus variegatus Mortensen, 1921 Test: Hemispherical, small form. Apical system: Genital plates with a single prominent tubercle at the inner end, suranal plate distinct. Ambulacra and interambulacra: With coarse and fairly numerous tubercles, leaving no naked median space, slight tendency of crenulation. Spines: Short. Color: The white test shows green or gray green spots, the apical plates are white, the periproctal plates green. The spines are banded more or less with red brown. Distribution: Northern New Zealand, off the Three Kings Islands to Cuvier Island at a depth of 65 to 120 m. Genus Salmaciella Mortensen, 1942 This genus differs from Salmacis by its eccentric anal opening. Test: Low or low conical, height less than half the diameter; oral side flat and deeply sunken toward the peristome. Apical system: Genital plates with some larger tubercles along the inner edge, the distal part is naked except for a few miliary tubercles; ocular plates usually exsert, O I may be insert, rarely also O V, all oculars densely tuberculated; periproct with tuberculated plates, anus opening eccentric toward genital plate 5; suranal plate only in juveniles distinct, inconspicuous in adults. Ambulacra: Around the ambitus, the primary tubercles are set off alternatively toward the inner and outer parts of the plates, sometimes even two on one plate; toward the apical system only on every second or third plate, finally disappearing; toward the peristome regular series with 1 tubercle on each plate; pore pairs in arcs of three forming a broad band. Interambulacra: Below the ambitus, 3–4 subequal tubercles in a horizontal row; on aboral side, a single primary tubercle

4.2.9 Order Camarodonta Jackson, 1912 

 245

to each plate, adapically leaving a naked median space. All primary tubercles strongly crenulated. Sculpture: Angular pits in inner and outer triple suture more or less distinct, aborally sometimes obliterated, orally always present, horizontal sutures more or less incised. Peristome: Deeply depressed, five small buccal plates and a few small plates near the distal edge, notches shallow and broad. Spines: Aborally short, longest at ambitus, somewhat downward directed like a fringe, distally widened and distinctly excavated. There are three species with discrete geographic ranges: Salmaciella dussumieri L. Agassiz, 1846. Japan to Torres Strait and Ceylon. Salmaciella erythracis H. L. Clark, 1912. Eastern Indian Ocean. Salmaciella oligopora H. L. Clark, 1916. Australia from Queensland to Tasmania, Philippines. The species of Salmaciella look very similar the colors of the spines providing the most reliable differences. Salmaciella dussumieri L. Agassiz, 1846 (Fig. 4.154 A–D) Characteristics of the genus. Color: Generally, the primary spines of the aboral side are dark purplish; the ambital ones banded with white and ending in a greenish point, at the oral side they are white. But they may be also more purplish or the green dominates. The denuded test is aborally greenish with lighter median areas, the oral side being whitish. Distribution: The species lives from Japan to the Torres Strait in the South and to Ceylon in the West at depths of 10 to 180 m. Salmaciella erythracis H. L. Clark, 1912 (Fig. 4.154 E, F) Characteristics of the genus. Test: Maximum diameter 38 mm. Color: The primary spines are banded in dark and light greenish tints; the small aboral spines are vermilion red, at least on the base; the test is a light grayish brown. Distribution: The species lives along the East African coast from Mozambique to Somalia and off the Seychelles at depths of 10 to 70 m. Salmaciella oligopora H. L. Clark, 1916 (Fig. 4.155) General characteristics of the genus. Test: Diameter up to 75 mm. Spines: The long ambital spines are widened distally with distinct shovel-like ends. Color: The spines have bands of white with brown, light green, or light olive. The bare test is pale fawn to light olive green in radial patterns.

246 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

F

E

Fig. 4.154: (A–D) Salmaciella dussumieri. (A) Side view with spines, test diameter ca. 40 mm; Philippines. ZMH. The long ambital spines are directed downward. (B) Apical system. The eccentric anal opening is shifted toward IA 5. (C) Aboral ambulacral plates. The tuberculation is rather sparse. (D) Oral ambulacral plates. The large tubercles are densely arranged. Scale: (B–D) 2 mm (Mortensen 1943). (E, F) Salmaciella erythracis. (E) Side view of test with some remaining spines, diameter 35 mm; Mozambique. ZMUC. The test is subconical. (F) Aboral side: the median areas in ambulacra and interambulacra are rather naked. The angular pits are small but distinct.

Distribution: The species is found along the east coast of Australia from Queensland to Tasmania and recently in the Philippines at depths between 10 and 90 m. Biology: Salmaciella oligopora lives in sheltered bays on open bottoms. It walks rapidly on its oral spines and can travel 42 cm in one minute (Miskelly 2002).

Genus Salmacis L. Agassiz, 1841 The genus is characterized by narrow, depressed lines along the sutures and small, but distinct pits in the angles. Test: Of moderate to large size; shape very variable, from subglobular to conical; ambitus usually rather low; oral side flattened, only slightly sunken toward the peristome.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 247

B

D

Fig. 4.155: Salmaciella oligopora. (A) Aboral side with spines, test diameter 41 mm; Shoal Bay, New South Wales, Australia. (B) Oral side: the primary spines are shovel-shaped. (C) Aboral side of test, diameter 31 mm; Shoal Bay, New South Wales, Australia. The horizontal and vertical sutures are slightly depressed; small deeper pits are positioned in the angles of the median sutures. (D) Oral side of test: the peristome with the shallow buccal notches is strongly depressed.

Apical system: Dicyclic; plates with a ring of larger tubercles along the inner edge; periproct subcentral, enlarged suranal plate only in juveniles. Ambulacra: 3 pore pairs per plate in oblique rows, a few tubercles on poriferous zone; one primary tubercle and a slightly smaller secondary per plate; of about same size as interambulacral tubercles. Interambulacra: Primary tubercles differentiated, flanked by slightly smaller secondaries, forming a series

of up to 5 tubercles on the oral side, a few scattered miliaries. Tubercles: Crenulated. Sculpture: Angular pits in triple sutures more or less distinct. Peristome: Slightly depressed, buccal notches shallow. Spines: Short, orally longest and widened. Remark: The genus Temnopleurus differs from Salmacis by having elongated furrows and/or vertical bands or rows

248 

 4.2 Subclass Euechinoidea Bronn, 1860

of conspicuous grooves. Salmacis is distinguished from Salmaciella by the ambulacral tuberculation, aborally each plate carries a primary tubercles – in the latter every second plate – and the less asymmetric apical disc. The genus consists of five species, which are difficult to distinguish due to their variability. Salmacis belli Döderlein, 1902. Malayan Archipelago. Salmacis bicolor A. Agassiz, 1846. Indo-West Pacific. Salmacis roseoviridis Koehler, 1927. Indian Ocean. Salmacis sphaeroides Linné, 1758. Indo-West Pacific. Salmacis virgulata L. Agassiz in L. Agassiz & Desor, 1846. Sri Lanka to Philippines and south Japan. Literature: Clark & Rowe 1971; Rowe & Gates 1995; Miskelly 2002. The species of Salmacis are difficult to distinguish, especially the bare tests. Salmacis belli Döderlein, 1902 (Fig. 4.156 A–C) Test: Conical, oral side flattened; diameter up to 75 mm, exceptionally to 95 mm. Apical system: Many small periproctal plates. Ambulacra: Two regular series of small primary tubercles, subequal secondaries in more or less irregular rows. Interambulacra: Horizontal series of primary and equalsized secondary tubercles, at the ambitus up to six in one row; densely packed toward the peristome; more sparse toward the apical system. Spines: Tapering to a sharp point; up to 18 mm in length at the ambitus. Color: The primary spines are banded in bright pink to red with yellowish pink to orange, the base is green. The bare test is a dull yellowish green to fawn with white tubercles. Biology: Salmacis belli sometimes clusters its aboral spines into cone-shaped tufts, showing its more or less bare median zones. Distribution: This species is found in the Philippines and the Malayan Archipelago and along the northern

coast of Australia from Shark Bay over Queensland to Botany Bay, New South Wales. It lives at depths of 10 to 125 m. Salmacis bicolor L. Agassiz, 1846 (Fig. 4.156 D, E) Test: Very variable from low to highly conical; diameter up to 100 mm. Ambulacra: Very regular series of primary tubercles, series of secondaries less regular. Interambulacra: Two rows of primary tubercles round the ambitus and at the oral side, with equal-sized secondaries forming horizontal series with up to 6 to 8 tubercles on one plate; toward the apical system, median zones rather bare. Sculpture: Pits small, horizontal sutures marked as fine depressed lines; sometimes lozenge-shaped pattern below primary tubercles in interambulacra. Spines: Slender and tapering to a distal point. Color: The spines are banded in red to violet and yellowish or greenish, the base brightly red. The bare test is dull greenish, the lozenge-shaped spots darker or purplish. Distribution: Salmacis bicolor is found in the Indian Ocean at East Africa from the Red Sea to Durban over Mauritius and Ceylon to Java and the Philippines, living from the littoral zone to 120 m. Salmacis roseoviridis Koehler, 1927 (Fig. 4.157) Test: High, subconical, the diameter may reach more than 70 mm. Apical system: Genital plates with scattered tubercles, largest near the periproctal edge, ocular plates densely covered by smaller tubercles; pits in the triple sutures present or absent, tuberculated periproctal plates. Ambulacra: Primary tubercles in two regular series, on the oral side large and with a second inner series;

Salmacis belli

Salmacis bicolor

Salmacis sphaeroides

Spines banded in pinkish red and yellowish, base green

Spines banded in red and yellowish to violet or green, base red

Spines banded in reddish brown, Spines uniformly purplish, not purplish, or green with white, banded, base white, sometimes base green also with white tip

Bare test dull, more or less uniformly dark green, sometimes with a slight purplish tinge, lozenge-shaped pattern sometimes

Bare test dull, more or less Bare test uniformly dark green, Bare test uniformly green uniformly dark green, sometimes or grayish green to entirely white with slight purplish tint, lozengeshaped pattern sometimes

Pore pairs at the ambitus distant Pore pairs at the ambitus distant Ambital pore pairs distant from from the outer edge of the from the outer edge of the the outer edge of the ambulacra ambulacra ambulacra

Salmacis virgulata

Pore pairs close to the outer edge of the ambulacra

4.2.9 Order Camarodonta Jackson, 1912 



A

 249

B

C

D

E

Fig. 4.156: (A–C) Salmacis belli. (A) Aboral side, diameter with spines 91 mm; Sydney, Australia. The upper spination is rather sparse, the spines are more densely packed at the ambitus and on the oral side. (B) Close-up of spines: they are banded in pinkish and yellowish green, the base is green. Scale: 10 mm. (C) Side view of test, Diameter 72 mm; Vaucluse Bay, New South Wales, Australia. The test is subconical. (D, E) Salmacis bicolor. (D) Side view with spines, test diameter 62 mm; Zanzibar, East Africa. ZMH. The spination on the upper side is sparser than around the ambitus and on the oral side. (E) Close-up of spines: they are banded in red and purplish, sometimes with green, the base is bright red.

aborally smaller and with only a few secondaries, median space bare. Interambulacra: Primary tubercles in two regular series, on the oral side up to five large ones per plate, aborally smaller, an inner and outer row of secondaries disappearing toward the apical disc. Peristome: Barely sunken. Color: Test greenish with lighter pore zones, rosy lozengeshaped patterns between the primary tubercles, growth

lines along the median suture. The spines are mostly not banded, they are red with a green base and often also a green tip. Distribution: This species is confined to the Indian Ocean from Sri Lanka to Burma. Bathymetric range 25 to 90 m. Remark: Mortensen (1943) emphasized that this species is almost equal to some specimens of Salmacis bicolor in the arrangement of the tubercles, the lozenge-shaped pattern aborally and the color of test and spines. They

250 

 4.2 Subclass Euechinoidea Bronn, 1860 Biology: Salmacis sphaeroides is found among corals near the low-tide mark, on sandy bottom, or among sea grass. The animals often hold leaves of algae or shell particles over their tests for camouflage. They are reported to feed on all sorts of bottom organisms, molluscs, worms, and algae.

Fig. 4.157: Salmacis roseoviridis. Side view with some oral spines, diameter of test 52 mm; Indian Ocean, off Myanmar. ZMUC. The spines are bright red with green.

may only be distinguished by the shape of the tridentate pedicellariae. Salmacis sphaeroides Linné, 1758 (Fig. 4.135 B, 4.158 A, B) Test: Very variable, from low and hemispherical to high or conical; oral side flattened; diameter up to 100 mm. Apical system: Small; densely covered with tubercles, except the madreporite, periproctal plates small; anal opening slightly eccentric. Ambulacra: Pore pairs in dense, oblique arcs of three, outer pores a little apart from the outer edges of the plates; rather conspicuous tubercles alternating with the pore pairs; two series of primary tubercles near the inner pores; small adapically, distinctly larger at the ambitus and orally. Interambulacra: Primary tubercles forming two regular series, and flanked by secondaries; at ambitus and orally secondaries reaching size of primaries. Sculpture: Angular pits at the edges of the sutures, in large specimens sometimes absent. Peristome: More or less depressed; buccal notches deep. Spines: Short and fine, slightly flattened and widened orally. Color: In living specimens, it can vary from nearly white to very dark green. The spines are densely banded in red brown, purple, whitish, or greenish, generally with a green base. The bare test is gray green, sometimes with radiating darker or lighter patches. Distribution: This species is known from Hong Kong to the Solomon Islands and along the north and east coast of Australia from the Exmouth Gulf to Sydney in the littoral zone and, exceptionally, down to a depth of 50 m.

Salmacis virgulata L. Agassiz in L. Agassiz & Desor, 1846 (Fig. 4.158 C, D) Test: Very variable, high, low, conical, or hemispherical; oral side broadly flattened; test diameter up to 120 mm. Apical system: Small; genital plates tuberculated only at the edge of the periproct, distally naked; ocular plates very small, pores at the end of slit-like indentations. Ambulacra: Pore zones narrow, the outer pores close to the edge of the plates, sometimes slightly enlarged; two regular series of primary tubercles close to the inner pore pairs, leaving adapically more or less naked median zones. Interambulacra: Very regular series of primary tubercles from the peristome to the apical system, secondaries also in regular series; larger at the ambitus; more or less naked median zones adapically. Sculpture: Horizontal sutures depressed; often lozengeshaped patterns; pits more or less conspicuous. Spines: Rather short, those on the oral side scarcely widened. Peristome: More or less depressed; buccal notches deep and rounded. Color: The spines are not banded, but dark bluish purple, the base whitish, often also the tip. They may be sometimes more reddish, or, rarely, white. The bare test is more or less uniformly greenish, the primary tubercles white. Distribution: Salmacis virgulata is known from Sri Lanka, Vietnam, and the Philippines to southern Japan. It lives in the sublittoral from 10 m down to 55 m. Genus Temnopleurus L. Agassiz, 1841 The genus is characterized by having deep pits or furrows of various size and shape along the horizontal sutures. Test: Mostly rather solid; low hemispherical to subconical, of small to medium size. Apical system: Dicyclic, (ocular I rarely insert); periproct subcircular with some larger plates, anal opening eccentric; tubercles on genital plates forming a ring around the periproctal edge. Ambulacra: 3 pore pairs per plate arranged in more or less steep arcs; the primary tubercle about as large as in interambulacra.

4.2.9 Order Camarodonta Jackson, 1912 



A

 251

B

D

C

Fig. 4.158: (A, B) Salmacis sphaeroides. (A) Side view of test, diameter 50 mm; Negros, Philippines. The test is conical with a flattened oral side. (B) Oral side with spines, diameter 63 mm; Siquijor, Philippines. The spines are larger than those of the aboral side and banded in green and purple. Those surrounding the peristome are flattened and slightly widened distally. (C, D) Salmacis virgulata. (C) Side view of test, diameter 69 mm; Philippines. (D) Oral side: on the upper side the tubercles are small and sparsely distributed; on the oral side, they are much larger and densely packed.

Interambulacra: One central primary tubercle plus smaller secondaries and miliaries. Tubercles: Distinctly crenulated. Sculpture: Large and deep grooves of wedge-shaped, rectangular, or rounded form, along the horizontal sutures: in interambulacra, two pits on either side of the primary tubercles; in ambulacra, a single smaller mostly triangular pit at triple junctions along the median line. Peristome: Small, buccal notches inconspicuous, membrane naked. Spines: Short to moderate length and simple, subambitally longer and often flattened.

Seven species are recorded in this genus, living in the Indo-Pacific: Temnopleurus alexandri Bell, 1884. North coast of Australia. Temnopleurus apodus A. Agassiz & H. L. Clark, 1907. IndoWest Pacific. Temnopleurus decipiens de Meijere, 1904. Indo-West Pacific. Temnopleurus hardwickii Gray, 1855. Off Japan and China. Temnopleurus michaelseni Döderlein, 1914. South and Western Australia. Temnopleurus reevesii Gray, 1855. Japan, Malayan region to East Africa. Temnopleurus toreumaticus Leske, 1778. Indo-Pacific. Literature: Shigei 1986; Rowe & Gates 1995.

252 

 4.2 Subclass Euechinoidea Bronn, 1860

B

A

C

D

E

F

Fig. 4.159: (A–D) Temnopleurus alexandri. (A) Side view of test, diameter 57 mm; Queensland, Australia. The furrows run along the whole length of interambulacral plates. (B) Oral side of test: furrows are absent on the oral side. (C) Aboral side with spines, diameter of test 61 mm; Queensland, Australia. ZMH. The spination is sparse the depressed sutures being visible. The conspicuously emerged tube feet form radiating white lines. (D) Oral side: the spines around the mouth are widened. (E) Temnopleurus apodus. Apical system. (F) Temnopleurus decipiens. Apical system. In both species, the suranal plates are large, pushing the anal openings toward IA 1. Scale: (E, F) 1 mm (Mortensen 1943).

Temnopleurus alexandri Bell, 1884 (Fig. 4.159 A–D) Test: Shape variable, spherical to low conical; maximum test diameter more than 80 mm. Apical system: Genital plates with some larger tubercles at the inner edge, ocular plates small, exsert;

periproctal plates small and numerous, anal opening near the center. Ambulacra: Broad interporiferous zones, two or three subequal tubercles to each plate forming more or less regular columns; 3 pore pairs per plate in oblique arcs.



Interambulacra: Up to 7 large tubercles in one horizontal series per plate. Sculpture: Horizontal sutures with sharply indented furrows, only interrupted below the primary tubercles; deep pits at the median sutures on the oral side; elongated pits in ambulacra; no naked areas. Peristome: Sunken, small buccal notches. Spines: Short, pointed, on the oral side flattened and slightly widened, distally smooth and shining. Color: Generally, the spines are more or less greenish at the base, distally more purplish; on the oral side often with a white tip. They may be also of uniform green, purple, pinkish, or white color. They are never banded. The bare test is generally more or less dark green, it may also be purple brown or white. Distribution: Temnopleurus alexandri is found in Australia from Sydney, New South Wales, round the northern coast to the Houtman Abrolhos Islands, Western Australia. It lives from the littoral zone to a depth of 50 m. Remarks: This species is distinguished from Temnopleurus michaelseni by its much larger size and by the color of its spines. In T. alexandri, the spines are of uniform size, whereas in T. michaelseni, the primary and secondary spines are clearly differentiated. Temnopleurus apodus A. Agassiz & H. L. Clark, 1907 (Fig. 4.159 E) Test: Low, diameter of test not more than 10 mm. Apical system: Very large, nearly smooth, large suranal plate, eccentric anal opening. Ambulacra: One primary tubercle per plate, usually alternating with a secondary one forming a single row. Interambulacra: Tuberculation scarce; primary tubercles finely crenulated. Sculpture: In both areas, very prominent, mainly forming irregular triangles. Peristome: Smaller than apical disc, only five buccal plates. Spines: Primaries slender, ambital ones hardly exceeding the diameter of test, finely serrate. Color: Test whitish mottled with light green; primary spines white basally, more red in the distal half. Distribution: Indo-West Pacific from Japan to Indonesia and East Africa, 160 to 500 m. Temnopleurus decipiens de Meijere, 1904 (Fig. 4.159 F) This small species as well differs from Temnopleurus apodus by its more prominent sculpture on test and apical plate, by the darker color and by its banded spines. Distribution: Indo-West Pacific, 18 to 40 m.

4.2.9 Order Camarodonta Jackson, 1912 

 253

Temnopleurus hardwickii Gray, 1855 (Fig. 4.160) Test: Rather strong, shape variable, mostly low hemispherical to subconical, oral side flattened; test diameter may reach 46 mm. Apical system: Often inflated, genital plates with numerous tubercles, distal part naked; periproctal plates naked, anal opening subcentral; ocular pores more or less piercing in a notch at the distal end of the plates. Ambulacra: Pore pairs in almost straight, vertical rows, close to the outer edge of the plates; primary tubercles in regular series, of same size as in interambulacra; smaller secondaries in parallel series; median areas conspicuously naked. Interambulacra: At the ambitus, 3 tubercles in more or less regular horizontal series per plate, primaries much larger than secondaries. Sculpture: Horizontal sutures in ambulacra and interambulacra with deep furrows in the median naked zones, which are continuous in larger specimens, like depressed zigzag bands with beveled sides; separated pits at the outer edge of plates; depressions almost absent on oral side. Peristome: Sunken, each pair of buccal plates closely set; notches inconspicuous. Spines: Short, less than a quarter of test diameter in large specimens, longer in smaller specimens. Color: The spines have a conspicuous dark brown base, the distal part is lighter brown or white; they are not banded. The bare test shows a green olive or pale green; the aboral median zones are often white, especially the pits or furrows; the oral side is light green or dirty white. Distribution: Temnopleurus hardwickii is known from Japanese coasts from southern Hokkaido to central Japan, around the Korea Peninsula and off North China at depths of 5 to 35 m. Remarks: The bare test of Temnopleurus hardwickii differs from that of Temnopleurus toreumaticus in having continuous pits with beveled edges; in the latter, they are separated and sharply cut. Temnopleurus michaelseni Döderlein, 1914 (Fig. 4.161) Test: Relatively small, low hemispherical; maximum diameter 25 mm. Apical system: All periproctal plates naked, suranal plate distinct and rounded, anal opening eccentric. Ambulacra: Pore pairs in almost straight series; primary tubercles relatively small, some smaller ones above them; secondaries forming distinct vertical series in the median area. Interambulacra: Tubercles in more or less distinct horizontal series. Sculpture: Pits variable, elongated furrows along the whole length of sutures, or short, separated pits at each side of plate.

254 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

D

C

Fig. 4.160: Temnopleurus hardwickii. (A) Aboral side of test, diameter 22 mm; Fujian Province, China. ZMH. (B) Close-up of aboral side: the grooves are rounded. Scale: 5 mm. (C) Aboral side with spines, diameter of test 36 mm; Shimizu, central Japan. The primary spines are well differentiated, being longer and darker than the secondaries. (D) Half an ambulacrum. Scale: 2 mm (Mortensen 1943).

Spines: In length, less than half the diameter of test. Color: The primary spines are red brown at the base, changing to green and tipped with white. They may be also uniformly red brown, purplish, or violet; the secondaries being white. They are never banded. The denuded

test is purple gray to greenish, sometimes with creamcolored spots. Distribution: This species is known from St. Vincent Gulf, South Australia, to Shark Bay, Western Australia, from the littoral zone to a depth of about 16 m.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

 255

C

Fig. 4.161: Temnopleurus michaelseni. (A) Aboral side of test, diameter 10 mm; Shark Bay, Western Australia. The grooves in ambulacra and interambulacra are deeply depressed. (B) Oral side of test. (C) Aboral side with spines, diameter 17 mm; Denmark, Western Australia. ZMH. The reddish brown primary spines contrast to the shorter whitish secondaries.

Remarks: Temnopleurus michaelseni differs from Temnopleurus alexandri by its smaller size. Temnopleurus reevesii Gray, 1855 (Fig. 4.162) Test: Fragile, hemispherical, or more flattened to subconical; test diameter usually 30–35  mm, exceptionally reaching 47 mm. Apical system: Ocular plates with small tubercles, more or less conspicuous prominence above each pore; periproctal plates nearly naked, suranal plate distinctly larger than the others, anal opening strongly eccentric. Ambulacra: Almost straight line of pore pairs, distant to the outer edge of the plates; primary tubercles of same size as interambulacral ones, forming a regular series, parallel rows of secondaries only around the ambitus. Interambulacra: At the ambitus, 3 tubercles to a plate forming regular, vertical series, the primary one in the middle distinctly larger than the two secondaries. Sculpture: The shape of the depressions in the horizontal sutures widely varies from shallow and lozenge-shaped furrows below the primary tubercles to small separated pits at the edges of the sutures; pits are also visible on oral side. Peristome: Sunken; buccal membrane naked, notches indistinct. Spines: Slender, about half the diameter of test, longer in small specimens; primary spines well differentiated, secondary spines with fine thorns. Color: The general color is light brown with a slight gray greenish tinge. The primary spines are darker brown the basal part may be lighter. The bare tests are gray brown above and white adorally; the median zones in ambulacra and interambulacra are a little darker.

Distribution: Temnopleurus reevesii occurs widely in the Indo-West Pacific; from Japan and the China Sea, through the Malayan Archipelago to the east coast of Africa, southward to Natal, at depths of 5 to 565 m. Remarks: This species is most easily distinguished from T. hardwickii and T. toreumaticus by its fragile test. The suranal plate in the apical system is large, and consequently, the eccentricity of the anal opening is more pronounced. In T. toreumaticus and T. hardwickii, the suranal plate is smaller and the anal opening subcentral. Temnopleurus toreumaticus Leske, 1778 (Fig. 4.135 A, 4.163) Test: Strong; shape varies from hemispherical to conical; oral side more or less sunken toward the peristome; maximum test diameter 60 mm. Apical system: More or less elevated; inner part of genital plates tuberculated, distal part naked; ocular plates with many small tubercles; suranal plate indistinct, anal opening subcentral. Ambulacra: About two thirds of the width of interambulacra; pore pairs in distinct arcs of three; primary tubercles of same size as in interambulacra, arranged in regular series, smaller secondaries in parallel series around the ambitus. Interambulacra: At the ambitus, 3–4 large tubercles per plate in one horizontal series; in large specimens, primaries and secondaries of about same size at the ambitus; secondaries continue only a little way onto the aboral side and become much smaller. Sculpture: Large, long, and deeply incised pits and furrows along the horizontal plate sutures, extending to the base of the primary spines, edges sharply cut; on the oral side, very small or absent.

256 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

D

C

Fig. 4.162: Temnopleurus reevesii. (A) Aboral side of test, diameter 12 mm; Natal, South Africa. (B) Side view of test. (C) Two specimens with spines, diameter of larger one 12 mm; Natal, South Africa. (D) Apical system: the eccentricity of the anal opening and the size of the suranal plate are more distinct in young specimens than in adults. Scale: 2 mm (Mortensen 1943).

Peristome: Edge distinctly sunken; pairs of buccal plates close set; notches shallow, almost not recognizable. Spines: Short, not exceeding a quarter of test diameter; often directed downward just below the ambitus; oral spines slightly widened and flattened distally. Color: The general color is dark olive. The spines show some narrow darker bands, especially on the oral side, where they may also have a slight pinkish tinge. The bare test is uniformly grayish olive. Distribution: Temnopleurus toreumaticus is known from East Africa and the Persian Gulf to the east coast of Australia. In Japan, this species is found from northern Honshu to southern Kyushu. It lives from the littoral zone to a depth of 45 m.

Remarks: Temnopleurus toreumaticus has banded spines, whereas in Temnopleurus hardwickii, they are not banded. The denuded test of the former has separated, sharply cut furrows, in the latter they are beveled and continuous. Genus Temnotrema A. Agassiz, 1863 The genus Temnotrema shows strong test sculpture similar to Temnopleurus, but differs in its smaller size and by the faintness or lack of crenulation of the tubercles. The grooves are also strongly developed over the oral side, whereas in Temnopleurus, they almost disappear beneath the ambitus (except in Temnopleurus reevesii). Test: Robust, in profile hemispherical or more or less highly domed.

4.2.9 Order Camarodonta Jackson, 1912 



A

 257

B

D C

Fig. 4.163: Temnopleurus toreumaticus. (A) Aboral side of test, diameter 45 mm; Sagami Bay, Japan. The furrows are deep and sharply indented. (B) Oral side of test. Toward the ambitus the furrows become narrower, disappearing almost or completely on the oral side. (C) Close-up of aboral side. Scale: 10 mm. (D) Aboral side with spines, diameter of test about 33 mm; Shimizu, Japan. The primary spines are banded, more conspicuously so on the oral side than on the aboral side.

Apical system: Small, ocular plates exsert; periproct with conspicuous suranal plate. Ambulacra: 3 pore pairs per arc, arranged in a single vertical series; one primary tubercle flanked or surrounded by several secondaries; one or two deep elongated pits in each horizontal suture. Interambulacra: One primary tubercle and several secondaries per plate. Sculpture: Large and sharp, elongated or wedge-shaped grooves along the horizontal sutures extending to triple

junction or crossing it, in ambulacra a single, in interambulacra two; primary tubercle often stellate being incised by pits; often also depressions at the apical plate sutures. Peristome: Small, virtually no buccal notches; membrane naked except for ten small buccal plates. Spines: Small and uniform. Color: The tests are more or less mottled in contrast to Temnopleurus, in which the colors are more uniform. Many species of Temnotrema are known. They are mostly small (except T. bothryoides with a maximum

258 

 4.2 Subclass Euechinoidea Bronn, 1860

Temnotrema bothryoides

Temnotrema elegans

Temnotrema maculatum

Temnotrema sculptum

Temnotrema siamense

Test olive green

Test greenish white, pore zones pink

Test whitish

Test with dark radiating patterns

Test red

Spines with intense scarlet bands

Spines with red violet or pink bands

Spines with faint brown bands

Spines red brown to yellow brown, tips white

Spines red, or with narrow green and brown bands

diameter of 40  mm) and very difficult to distinguish, especially from their bare tests. Temnotrema bothryoides L. Agassiz, 1846. Northern Australia. Temnotrema elegans Mortensen, 1918. Northeast and Western Australia. Temnotrema hawaiiense A. Agassiz & H. L. Clark, 1907. Restricted to the Central Pacific. Temnotrema maculatum Mortensen, 1904. Malayan Archipelago to the Torres Strait. Temnotrema pallescens H. L. Clark, 1925. Philippines and Indonesia. Temnotrema phoenissa H. L. Clark, 1926. May prove to be synonymous with T. pulchellum. Temnotrema pulchellum Mortensen, 1904. Malayan Archipelago to east Australia. Temnotrema reticulatum Mortensen, 1904. Malayan region. Temnotrema rubrum Döderlein, 1885. Japan. Likely to be synonymous to T. sculptum. Temnotrema scillae Mazzetti, 1894. Indian Ocean. Temnotrema sculptum A. Agassiz, 1863. Japanese waters. Temnotrema siamense Mortensen, 1904. East Africa to northeast Australia. Temnotrema xishaensis Liao, 1978. South China Sea. Literature: Clark & Rowe 1971; Shigei 1986; Rowe & Gates 1995. Temnotrema bothryoides L. Agassiz, 1846 (Fig. 4.164 A, B) Test: Thick and subglobular, diameter up to 40 mm. Apical system: Ocular plates with an elevated inner part, the pore hidden below its edge; genital plates also more or less with inner part elevated, but not so sharply delimited; suranal plate rather inconspicuous, anal opening subcentral. Ambulacra: Few larger tubercles, scattered miliaries, pore pairs in steep arcs. Interambulacra: One row of larger primary and secondary tubercles, scattered miliaries. Sculpture: Along the horizontal sutures, deep grooves on either side of the primary tubercle. Color: The pits are dark olive green, pore zones and tuberculated parts more or less whitish or light green giving the

test a radiating appearance. The spines are banded with scarlet red. Distribution: Known from northern Australia from Dampier to the Great Barrier Reef, 3–35 m deep. Temnotrema elegans Mortensen, 1918 (Fig. 4.164 C–F) Test: Thick, shape variable, globular or high conical; maximum diameter 30 mm. Apical system: Genital and ocular plates with more or less distinct transverse edges separating the inner elevated part from the distal lower part. Ambulacra and interambulacra: With a single horizontal series of tubercles on each plate, surrounded by scattered miliary tubercles; deep grooves in the horizontal sutures. Spines: Short and fine. Color: Test greenish to gray, pore zones often with a pink tint, spines banded in red violet to pink red and white. Distribution: Known from Western Australia between Broome and Fremantle and from the Great Barrier Reef, northeast Australia, at depths between 9 and 27 m. Remark: Mortensen (1943) admits that Temnopleurus elegans differs from Temnopleurus bothryoides only by the color. Temnotrema hawaiiense A. Agassiz & H. L. Clark, 1907 (Fig. 4.165 A, B) Characteristics of the genus. Maximum recorded diameter 12 mm. Sculpture: Beside the large grooves along the horizontal sutures also small pits around the primary tubercles, giving them a stellate appearance. Color: The test is variably green to white, the spines are white with more or less red. There occur also varieties with uniform red test and spines. Distribution: The species is restricted to the Central Pacific. Bathymetric range 1 to 400 m. Temnotrema maculatum Mortensen, 1904 (Fig. 4.165 C) Test: Size hardly reaching 18 mm. Apical system: Genital plates with a distinct transverse edge.

4.2.9 Order Camarodonta Jackson, 1912 



A

D

 259

C

B

F

E

Fig. 4.164: (A, B) Temnotrema bothryoides. (A) Apical system: the inner part of the ocular plates is distinctly elevated and the pores are not visible from above. The inner part of the genital plates is also higher than the outer part. Deep pits occur in the angles between the plates. (B) Ambulacral plates: the grooves along the median horizontal sutures are deeply depressed. Scale: 1 mm (Mortensen 1943). (C–F) Temnotrema elegans. (C) Aboral side with remaining spines, diameter of test 26 mm, height 18 mm; Dirk Hartog Island, Western Australia. (D) Side view of test. The grooves in the horizontal sutures are deep continuing to the peristomial edge. (E) Oral side. (F) Aboral side with spines, diameter 12 mm; Shark Bay, Western Australia. ZMH. The large primary spines are banded, the small miliaries pinkish brown.

Ambulacra: Steep arcs of pore pairs. Interambulacra: At ambitus, horizontal rows of larger tubercles. Spines: Short and fine. Color: Test whitish, spines banded in reddish brown. Distribution: This species is found in the Malayan region and southward to northeast Australia at depths between 10 and 80 m.

Temnotrema pallescens H. L. Clark, 1925 (Fig. 4.165 D) Characteristics of the genus. Maximum recorded diameter 14 mm. Color: Test green with a purplish tint, the pits may be quite green, yellowish, or dark; spines pale lavender, the primaries with white tip, often with one or two indistinct dusky bands.

260 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

Fig. 4.165: (A, B) Temnotrema hawaiiense. (A) Aboral side of test, diameter 7 mm; Palmyra Island, Central Pacific. ZMUC. (B) Oral side of test. (C) Temnotrema maculatum. Aboral side partly with spines, diameter 9 mm; Torres Strait. ZMH. The spines are very fine. (D) Temnotrema pallescens. Oblique view with some spines, test diameter 10 mm; Jolo, Philippines. ZMUC.

Distribution: Indonesia and Philippines. Recorded depth 35 to 50 m. Temnotrema pulchellum Mortensen, 1904 (Fig. 4.166 A, B) Test: Thick, regularly hemispherical, diameter of test up to 13 mm. Apical system: Distal part of the genital plates markedly set off, inner part with 2 to 3 large tubercles, ocular plates with a single large tubercle. Ambulacra: Regular series of primary tubercles, one inner series of smaller secondaries.

Interambulacra: Regular series of primary tubercles, parallel series of smaller secondaries; many scattered miliaries. Spines: Short and smooth. Color: The test is red or purplish, somewhat greenish brown along the midlines, adorally white; spines uniformly red or purplish with a white tip. Distribution: Recorded from the Philippines to the Great Barrier Reef (including T. phoenissa). Bathymetric range 25 to 75 mm. Remark: May prove to be synonymvous with T. phoenissa H. L. Clark, 1926 (Rowe & Gates 1995).

4.2.9 Order Camarodonta Jackson, 1912 



A

B

D

 261

C

E

F

D

Fig. 4.166: (A, B) Temnotrema pulchellum. (A) Aboral side with some spines, diameter of test 9 mm; Kei Island, Indonesia. ZMUC. (B) Oral side: the buccal plates are very small. (C–F) Temnotrema reticulatum. (C) Aboral side of test. (D) Side view of test, diameter 5.5 mm; Bali, Indonesia. ZMUC. (E) Ambulacral plates. (F) One series of interambulacral plates. Scale: 1 mm (Mortensen 1943).

Temnotrema reticulatum Mortensen, 1904 (Fig. 4.166 C–F) Characteristics of the genus. Maximum recorded diameter 6.5 mm. Test: Hemisperical. Apical system: Suranal plate very large, covering almost the whole periproct the anal opening being eccentric and very close to the edge. Sculpture: Beside the large grooves along the horizontal sutures also small pits around the primary tubercles, giving them a more or less stellate appearance. Color: Test whitish with green or brown olive radiating stripes; spines with faint bands. Distribution: This species lives in the entire Malayan region to New Britain. Bathymetric range 25 to 125 mm. Remark: Temnotrema reticulatum ist very similar to T. scillae, but differs mainly in the large size of the suranal plate.

Fig. 4.167: Temnotrema rubrum. Side view of test, diameter 13 mm; Japan. ZMUC. The test is relatively high. The pore pairs form almost a straight vertical series, which is distinctly depressed.

Temnotrema rubrum Döderlein, 1885 (Fig. 4.167, 4.168 A) Characteristics of the genus. Sculpture: Distinct more or less triangular pits in the triple junctions of sutures.

Color: Test and spines reddish. Distribution: Restricted to Japanese waters. Remark: According to Shigei (1986), this species is synonymous with T. sculptum, being a red-colored variety.

262 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

Fig. 4.168: (A–B) Temnotrema rubrum Aboral side of test; diameter 13 mm, Japan. ZMUC. (B) (A) Temnotrema scillae. Aboral side of test, diameter 8 mm; Muscat, Oman. ZMUC. The colors are mottled. (C, D) Temnotrema sculptum. (C) Aboral side of test, diameter 19 mm; Shimizu, Japan. (D) Side view. The pattern gives the test a radiating appearance.

Temnotrema scillae Mazzetti, 1894 (Fig. 4.168 B) Main characteristics of the genus Apical system: Suranal plate not covering the whole periproct in contrast to the very similar T. reticulatum. Primary tubercles: Rather large, above the ambitus abruptly decreasing in size. Sculpture: Pits also in the apical plate sutures. Color: Mottled in white and brown, usually with distinct brown spot in both areas and radiating dark stripes. Primary spines whitish with inconspicuous bands in brown or reddish.

Distribution: Restricted to the Indian Ocean from East Africa to the Andaman and Mergui Island. Bathymetric range 25 to 100 m. Temnotrema sculptum A. Agassiz, 1863 (Fig. 4.168 C, D) Test: Small, high domed, oral side flattened, diameter of test not more than 25 mm. Apical system: Small and elevated; genital plates with large pores, outer part distinctly lower than the inner part, with 3–5 tubercles along the periproctal edge; ocular plates usually with small, raised, keeled

4.2.9 Order Camarodonta Jackson, 1912 



A

B

 263

C

Fig. 4.169: (A) Temnotrema sculptum. Aboral side with spines, diameter 12 mm; Fukui Prefecture, Japan. The spines are short, stout, and densely packed (photo by W. Clarenbach). (B, C) Temnotrema siamense. (B) Aboral side of test, diameter 9 mm; Persian Gulf. ZMUC. (C) Apical system. No scale. Mortensen 1904.

A

B

C

Fig. 4.170: Epistromal pattern of Trigonocidaridae. (A) Ambulacral plates. (B) Interambulacral plates. (C) Apical disc. Trigonocidaris albidioides. Scale: 2 mm (Mortensen 1943).

prominences distally, pore below this keel not visible from above. Ambulacra: 3 pore pairs per plate forming a straight, vertical series close to the outer edge; primary tubercles in two regular series, of same size as interambulacral tubercles; secondaries subequal in size. Interambulacra: Plates densely tuberculated: primary tubercles with slightly smaller secondaries forming more or less regular, horizontal series of 3–5 tubercles, additional irregular series of smaller ones. Sculpture: Horizontal sutures with elongated, more or less triangular grooves at each end of interambulacral plates, in ambulacra only along median suture. Primary tubercles slightly crenulated. Spines: Very short, rather robust, distal end truncated. Color: The spines are reddish brown or yellowish brown at the base, banded and tipped with white, sometimes they may be uniformly reddish brown, light greenish, or

whitish. The bare test has a conspicuous radial pattern in white and olive brown, sometimes more reddish brown or rarely whitish; genital plates dark olive, at least in their distal parts. Distribution: Temnotrema sculptum is known from Japanese seas around Honshu to Kyushu and from the eastern Chinese Sea at depths of 5 to 500 m. Temnotrema siamense Mortensen, 1904 Main characteristics of the genus. Maximum diameter of test 12 mm. Apical system: Subanal plate large. Sculpture: Grooves in ambulacra and interambulacra, pits in apical system. Color: Very variable, greenish, red brown or pinkish with white spots, median zones in interambulacra as darker radiating stripes; primary spines with narrow bands in green or brown.

264 

 4.2 Subclass Euechinoidea Bronn, 1860

Distribution: Widespread in the Indo-West Pacific from East Africa to northeast Australia and the South China Sea. Bathymetric range 5 to 350 m. Temnotrema xishaensis Liao, 1978 Reported from off the Xisha Islands, Guangdong Province, South China.

4.2.9.3 Family Trigonocidaridae Mortensen, 1903 The members of this family display strong test sculpture similar to those in the family Temnopleuridae. The difference is that in the Temnopleuridae, the sharp-edged depressions or more or less small pits are developed along the horizontal and/or vertical sutures. In the Trigonocidaridae, the depressions lie above the surface of the plates, the elevated ridges are epistromal. The family consists of six extant genera. Asterechinus Mortensen, 1942. One species. Desmechinus H. L. Clark, 1923. Three species; Malayan region. Genocidaris A. Agassiz, 1869. One species; Mediterranean and adjacent Atlantic, West Africa southward to the Congo. Hypsiechinus Mortensen, 1903. One species; North Atlantic. Prionechinus A. Agassiz, 1879. Four species. Trigonocidaris A. Agassiz, 1869. Six species. Lamprechinus Döderlein, 1905 and Orechinus Döderlein, 1905 are synonymized with Trigonocidaris. Genus Asterechinus Mortensen, 1942 The monospecific genus is characterized by radiating ridges around the primary tubercles, the boss being more or less indented. Asterechinus elegans Mortensen, 1942 (Fig. 4.171) Test: More or less low hemispherical, on oral side slightly flattened; diameter hardly 30 mm. Apical system: Ocular plates widely exsert with miliary tubercles on the inner part of plate; genital plates with larger tubercles around the periproctal edge; suranal plate distinct, anal opening eccentric. Ambulacra: Pore pairs in distinct arcs of three; one primary tubercle per plate, in regular series, smaller than on interambulacra; radiating ridges and miliary tubercles. Interambulacra: Regular series of primary tubercles, secondaries much smaller. Sculpture: Elongated ridges and numerous miliary ­tubercles forming radiating patterns around the primary tubercles.

Fig. 4.171: Asterechinus elegans. Side view of test, diameter 27 mm; Admiralty Islands. There are radiating ridges around the primary tubercles on the median areas in ambulacra and interambulacra (photo by Bas van der Steld).

Primary tubercles: Crenulated and indented at the base, in young specimens more distinct than in adults. Peristome: Membrane naked, buccal plates large, almost continuous. Spines: Slender, barely reaching half the diameter of test, finely thorny. Color: Test reddish brown, pore zones lighter red, oral side whitish; spines red at the base becoming gradually white toward the tip. Distribution: The species is recorded from the Admiralty Islands (Papua New Guinea). Depth 270 m. Genus Desmechinus H. L. Clark, 1923 The genus is characterized by more or less radiating depressions surrounding the primary tubercles and by a strongly eccentric apical system. In young specimens, the median areas in the interambulacra show also conspicuous triangle-shaped sculptures that disappear with age. Test: Medium-sized, in profile low. Apical system: More or less oblique toward genital plate 1, oculars I and II may be broadly insert; periproctal plates numerous and rather large; suranal plate not very conspicuous. Ambulacra: Pore pairs arranged in distinctly oblique series of three. All primary tubercles non-crenulate; in two regular series, secondaries present in ambital region. Sculpture: In young specimens, median zone in both areas occupied by large triangular depressions leaving only narrow oblique ridges between primary tubercles; in adults, the aboral median area is totally smooth, on adradial sides ridges set with secondaries.



Peristome: Small, sunken, with sharp buccal notches; membrane naked. Three species are included: Desmechinus anomalus H. L. Clark, 1923. China Sea, not well known. Desmechinus rufus Bell, 1894. Malayan Archipelago, reddish. Desmechinus versicolor Mortensen, 1904. Malayan Archipelago. Desmechinus anomalus H. L. Clark, 1923 Not well known. Test: Diameter of only recorded specimen 39 mm. Sculpture (of the adult): narrow wall connecting the primary tubercles, small indentations at the base of the tubercles. Color: Test dull purplish. Occurrence: China Sea. Depth unknown. Desmechinus rufus (Bell, 1894) Test: Low, flattened above; test diameter up to 21 mm. Apical system: Usually no ocular plate insert, anal opening moderately eccentric. Ambulacra: Pore pairs in rather dense oblique series of three; primary tubercles in two regular vertical series. Interambulacra: Primary tubercles in two regular vertical series, admedian row of secondary tubercles, a few others are scattered on the plate, median space bare. Sculpture: In ambulacra and interambulacra of young specimens, the median area is covered by triangle-shaped depressions crossing the midline and a conspicuous network of depressions round the tubercles; in adults, leaving more or less distinct indentations around the base of the primaries and the larger secondaries, the primaries being additionally connected by a narrow wall. Spines: Hardly exceeding one fourth of test diameter. Color: The spines are generally red on the aboral side, orally rather white to green with narrow bands of red. The test is aborally red with distinct broad transverse and radial bands in white on ambulacra and interambulacra or irregularly mottled in red and white. Distribution: Widespread in the Malayan Archipelago from the Macclesfield Band and the Philippines to the Timor Sea. Bathymetric range 20 to 80 m. Desmechinus versicolor Mortensen, 1904 (Fig. 4.172) Test: Low, subconical or flattened above, diameter of test up to 26 mm. Apical system: Strongly eccentric, anal opening lying close to genital plate I, ocular plates I and/or II broadly insert; periproct with large plates.

4.2.9 Order Camarodonta Jackson, 1912 

 265

Ambulacra and interambulacra: Very similar to Desmechinus rufus. Spines: Longest at the ambitus with hardly one third of diameter of test, on the oral side shorter and straight; primaries quite smooth, secondaries with faint thorns. Color: The test is white, with a more or less brown or olive tinge in the median areas; the spines are banded in red and white or green with a red tip. Distribution: From the China Sea to the Kei Islands, Indonesia. Bathymetric range ca. 70 to 100 m. Remarks: Desmechinus rufus differs from D. versicolor by the bright red color of the test, which is interrupted by broad white vertical and horizontal bands. The sculpture is similar. Genus Genocidaris A. Agassiz, 1869 The monospecific genus is characterized by its very large suranal plate, which displaces the anal opening toward ocular plate I. Genocidaris maculata A. Agassiz, 1869 (Fig. 4.173) Test: Very small, hemispherical, diameter up to 12 mm. Apical system: Genital plates with a few tubercles concentrated on the inner part; periproct with very large, shining suranal plate that is often radially striated. Ambulacra: Pore pairs in almost straight vertical series; one large primary tubercle per plate, surrounded by dense secondary and miliary tuberculation. Interambulacra: One large primary tubercle in the middle of the plate, distinct among the numerous secondaries and miliaries; on ambulacra and interambulacra of same size. Sculpture: Surface of the apical plates more or less uneven with fairly distinct furrows crossing the sutures; larger tubercles in both areas more or less indented around the base. Peristome: Quite naked except for the small buccal plates; notches very small. Spines: Primary spines smooth and with blunt tip, not longer than 2 mm. Color: There is much variation: the test may be olive green, olive brownish or reddish, usually more or less mottled with white. The spines are banded with two or three narrow reddish bands. Distribution: The species is widespread in the Atlantic from the Caribbean northward to Cape Hatteras, around the Azores and Canaries, at the west coast of Africa southward to the Congo, and in the Mediterranean as far as Egypt in the East. Bathymetric range 12 to 420 m. Genus Hypsiechinus Mortensen, 1903 The species Hypsiechinus coronatus is the only temnopleurid living in cold waters. Occurring in the northeast Atlantic, it is also the only marsupiate temnopleurid remaining since

266 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

E

Fig. 4.172: Desmechinus versicolor. (A) Aboral side of test with some spines, diameter 18 mm; Kei Island, Indonesia. ZMUC. (B) Side view: there are radiating ridges around the primary tubercles. (C) Ambulacral plates. (D) Interambulacral plates. (E) Apical system: the anal opening is strongly eccentric lying close to genital plate I. Scale: 3 mm (Mortensen 1943).

A

B

C

Fig. 4.173: Genocidaris maculata. (A) Several tests, diameter of largest specimen 7 mm; West Africa. The color variation is large. (B) Oral side of test. The buccal notches are very small. The tubercles do not decrease in size toward the peristomial edge. (C) Apical system. The suranal plate is very large. Scale: 1 mm (Mortensen 1943).

4.2.9 Order Camarodonta Jackson, 1912 



the Eocene period, when many fossil Temnopleuridea were common in northwestern Europe. Some of them were marsupiates sheltering their young in brood pouches on the upper side of their test. Hypsiechinus coronatus carries its juveniles around the raised apical system. Hypsiechinus coronatus Mortensen, 1903 (Fig. 4.174) Test: Low, flattened above and below; maximum diameter 9 mm.

A1

 267

Apical system: Large, in males and juveniles slightly raised, ocular plates small, naked and widely exsert, genital plates with one or two larger tubercles; madreporite with only 2 to 3 pores; periproct naked with one large plate and a few smaller ones. In females, the ocular and especially the genital plates are strongly elongated and raised forming a very conspicuous knob; the lower part of the genital plates and the entire ocular plates are smooth, the inner (upper) parts of the genital

B

A3

A2

C

D

Fig. 4.174: (A) Hypsiechinus coronatus. (A1) Test about 8 mm in diameter, aboral, side, oral. (A2) Close-up of female test: the densely tuberculated upper parts of the genital plates are raised forming a knob. The miliary spines of these areas are bent over the smooth lower parts of the genital plates. The uppermost coronal plates are also set with numerous miliary tubercles. The periproctal plates cover the top of the knob. (A3) Enlargement of female test with spines and juveniles. No scales (Mortensen 1903). (B) Test of female, diameter 7 mm; southwest of Iceland. ZMUC ECH 10. View onto the apical knob and the aboral side of the test: the periproctal plates on the top are complete. (C) Aboral side of male, diameter 9 mm; southwest of Iceland. ZMUC ECH 97. The apical disc is conically raised with the periproct in the center. (D) Aboral side of female, diameter 6 mm; southwest of Iceland. ZMUC. The periproctal plates are lost: the miliary spines from above and below cover densely the smooth area around the knob where the juveniles are sheltered.

268 

 4.2 Subclass Euechinoidea Bronn, 1860

plates are densely set with numerous miliary tubercles; gonopores large and nearer to the distal edge of the plate; periproct at the top of the knob plates arranged as in males. Ambulacra: Pore pairs in almost straight vertical series; plates relatively high, one primary tubercle per plate. Interambulacra: Regular series of primary tubercles; adapical plates in males rather smooth, in females densely covered with miliary tubercles, the surface having a more or less distinctly grooved appearance or the pattern is netshaped. Sculpture: Primary tubercles with distinct indentations at the base. Peristome: Large, buccal notches indistinct. Spines: Primaries about half the diameter of test. Distribution: This tiny species occurs south and west of Iceland and in the Strait of Denmark at depths of about 810 to 1,340 m. Reproduction: The eggs are released onto the smooth parts of the genital plates under the dense spination, which is formed by the miliary spines of the upper coronal plates from below and of the raised inner part of the genital plates from above. Mortensen (1903) reported on 3 to 7 eggs of about 0.5 mm in diameter. The young may be found in the same developmental stage or they are grown individually in different stages. Genus Prionechinus A. Agassiz, 1879 This genus is characterized by sexual dimorphism the gonopores in females being round and in the center of the plate or even nearer to the periproctal edge, in males very small and at the distal point of the plate. There is no sculpture on test plates, but on apical plates. Test: Small, hemispherical with flattened oral side. Apical system: In adult specimens, plates densely tuberculated; in smaller specimens, tubercles much fewer; periproct covered by several rather large plates, suranal plate more or less conspicuous. Ambulacra: About half the width of interambulacra, pore pairs in distinct arcs of three, slightly crowded at the peristomial edge; perfectly regular series of primary tubercles as large as interambulacral ones, secondary tubercles much smaller. Interambulacra: Regular series of primary tubercles. Sculpture: Mostly no trace of depressions. However, in some species, the apical plates may be sculptured, but that is not a constant characteristic according to Mortensen (1943) and H. L. Clark (1907). Peristome: Buccal plates may form a closed ring or may be separated, distal part naked, well plated inside the buccal plates.

Spines: Slightly serrated, at ambitus half the test diameter, more or less flattened; orally short and simple, aborally short, very brittle, although they look robust. The genus includes four species. Prionechinus agassizi Wood-Mason & Alcock, 1891. Indian Ocean. Prionechinus forbesianus A. Agassiz, 1881. Indo-West Pacific. Prionechinus sagittiger A. Agassiz, 1879. Malayan Archipelago. Prionechinus sculptus A. Agassiz & H. L. Clark, 1907. Hawaii; 350 to 1,255 m. Prionechinus agassizii Wood-Mason & Alcock, 1891 (Fig. 4.174 A) Test: Height more than half the diameter, which may reach up to 16.5 mm. Apical system: Suranal plate inconspicuous. Interambulacra: Median line distinctly sunken. Distribution: Recorded in the Indian Ocean from the Pemba Strait and Tanzania to Sumatra, Indonesia. Bathymetric range 420 to 3,310 m. Remark: This species differs from the other Prionechinus species by its depressed median line in the interambulacra. Prionechinus forbesianus A. Agassiz, 1881 (Fig. 4.175 B, C) Test: Hemispherical, height less than half the diameter; diameter may reach 17 mm. Apical system: Suranal plate usually conspicuous. Color: Spines reddish with white or darker tip, test also reddish to pink, in some specimens darker, in others almost white. Distribution: This species is widespread in the West Pacific from the Japanese Sea through the Malayan Archipelago to the Fiji Islands. Bathymetric range 260 to 1,370 m. Remark: Prionechinus forbesianus differs from Prionechinus sagittiger by the reddish color. In the former, the periproctal covering is rather coarse; in the latter, finer with a distinct suranal plate. Prionechinus sagittiger A. Agassiz, 1879 (Fig. 4.175 D, E) Test: Diameter not more than 7.5 mm. Apical system: Suranal plate very conspicuous among small plates; sexual dimorphism in the position of the gonopores: in females, more or less central; in males, on the distal edge in a small depression. Peristome: Buccal plates large; often only one of the pair may carry a buccal foot. Distribution: Seems to occur throughout the Malayan region at a depth of 325 to 1,950 m.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

D1

C

 269

D2

E

Fig. 4.175: (A) Prionechinus agassizii. Aboral side of male with spines, diameter 10 mm; Nias-Channel, Sumatra. MfN, holotype of P. chuni Döderlein, 1906, syn. with P. agassizii. (B, C) Prionechinus forbesianus. (B) Aboral side of female, diameter 17  mm; Northeast Taiwan. The gonopores are conspicuously red. (C) Oral side of female: the buccal plates on the peristome are large leaving a distal naked area along the edge of the test. (D, E) Prionechinus sagittiger. (D1) Apical system of male. (D2) Apical system of female. Scale: 1 mm (Mortensen 1943). (E) Aboral side of test, diameter 7 mm; Celebes, Indonesia. ZMUC. The periproctal plates are small, the suranal plate being well differentiated.

270 

 4.2 Subclass Euechinoidea Bronn, 1860

Prionechinus sculptus A. Agassiz & H. L. Clark, 1907 (Fig. 4.176 A, B) Main characteristics of the genus. Usually, the sculpture on the apical plates is strongly developed. However, in some specimens, it may be totally lacking. The midline of the interambulacra is sunken. Distribution: The species is restricted to the Hawaiian Islands. Recorded at depths of 350 to 1,255 m. Genus Trigonocidaris A. Agassiz, 1869 The genus is characterized by having four large periproctal plates, displacing the anal opening more or less toward ocular plate I. The coronal plates are sculptured by irregular epistromal ridges. Often, the apical plates also show more or less distinct depressions. Test: Small, low with flattened upper and lower side or hemispherical. Apical system: Dicyclic, more or less distinctly sculptured, periproct usually with four large plates, one of them is the suranal plate; anal opening more or less eccentric. Ambulacra: Pore pairs in nearly straight vertical series. Sculpture: Plates strongly sculptured in ambulacra and interambulacra, the tubercles on elevated ridges. Primary tubercles: May be faintly crenulated, especially on the oral side. Peristome: Buccal membrane more or less covered by large, imbricating plates; buccal notches inconspicuous. Spines: Short, simple, and smooth, tapering distally. Nine extant species are reported in this genus: Trigonocidaris albida A. Agassiz, 1869. West Indies, East Atlantic. Trigonocidaris albidioides A. Agassiz & H. L. Clark, 1907. Hawaii. Trigonocidaris indica Mortensen, 1942. Madagascar, 125 m. Trigonocidaris micropora Mortensen, 1942. Malayan Archipelago. Trigonocidaris monolini A. Agassiz, 1879. Indo-West Pacific. Deep sea. Trigonocidaris nitidus Döderlein, 1905. South Africa. Deep sea. Trigonocidaris radiata Mortensen, 1942. Kei Islands, 600 m. Trigonocidaris sculptus Mortensen, 1942. Indo-West Pacific, Hawaii. Trigonocidaris tuberculata Markov, 1989. Fidji Islands, central Pacific. Trigonocidaris versicolor Koehler, 1927. Andaman Islands. The species are rather similar in their sculpture, and considerable individual variation occurs. Mortensen distinguished them mainly by their pedicellariae and their geographic distribution.

Trigonocidaris albida A. Agassiz, 1869 (Fig. 4.176 C, D) Characteristics of the genus. Test: Diameter may reach 13 mm. Apical system: Periproctal plates rather smooth; genital plates with only a very few tubercles at the periproctal edge. Color: Test whitish, the distal part of the apical plates a light orange red or greenish yellow; sometimes small green spots aborally; aboral spines white with white bases, orally sometimes with a red band. Distribution: The species is widespread in the West Indies and from the Azores and Madeira to the Bay of Biscay. Bathymetric range 70 to 700 m. Trigonocidaris albidioides A. Agassiz & H. L. Clark, 1907 (Fig. 4.170 C) The species resembles very much to Trigonocidaris albida. The main difference is in the color: the aboral spines of T. albidioides have a broad band of red or a red point, but the apical plates are not reddish or green as in T. albida; however, there are also small green spots on the aboral test as in the latter. Distribution: The species is restricted to the Hawaiian Islands at a depth of 225 to 590 m. Trigonocidaris indica Mortensen, 1942 Very similar to Trigonocidaris albida. Trigonocidaris indica differs in the lack of depressions on the test and the presence of tridentate pedicellariae (not found on T. albida). Occurrence: The two small specimens were found off Providence Island, north of Madagascar. Depth 125 m. Trigonocidaris micropora Mortensen, 1942 (Fig. 4.176 E, F) Maximum diameter of test 15 mm. Color: Periproctal plates green; spines greenish at the base, tip white. Test may be more or less mottled in green and whitish. Distribution: Recorded throughout the Malayan Archipelago. Bathymetric range 240 to 350 m. Trigonocidaris monolini A. Agassiz, 1879 (Fig. 4.177 A, B) Test: Low hemispherical, diameter up to 14 mm. Apical system: Ring of tubercles; gonopores on elevated ridges. Ambulacra: Pore pairs in an almost straight vertical row, broad interporiferous zone; large primary tubercles. Interambulacra: One primary tubercle per plate forming two distinct parallel rows; sculpture strong, in the main transversely positioned, on oral side less deeply developed. Peristome: Pentagonal, membrane naked except buccal plates.

4.2.9 Order Camarodonta Jackson, 1912 



A

B1

 271

B2

C

D

E

F

Fig. 4.176: (A) Prionechinus sculptus. Aboral side of test, diameter 5 mm; Hawaiian Islands. ZMUC. (B) Prionechinus sculptus. (1) Apical system of female. (2) Apical system of male. Scales: (1) 1 mm; (2) 2 mm (Mortensen 1943). (C, D) Trigonocidaris albida. Aboral side of test, diameter 10 mm; North Atlantic. ZMUC. The periproct is covered by large, imbricating plates. (D) Oral side with spines, diameter of test 12 mm; Florida Keys, USA. ZMUC. The peristomial membrane is densely plated. (E, F) Trigonocidaris micropora. (E) Aboral side partly with spines, diameter of test 15 mm. ZMUC ECH 579. (F) Oral side partly with spines: the buccal plates are densely packed.

Spines: Adoral primaries flattened and curved. Color: Test and spines pure white. Distribution: Widespread in the Indo-Pacific from Hawaii through the Malayan region and the Kermadec Islands to South Africa, at depths of 318 to 2,300 m. Trigonocidaris nitidus Döderlein, 1905 (Fig. 4.177 C, D) Test: Low hemispherical, diameter less than 15 mm.

Apical system: Smooth or only shallowly sculptured, periproctal plates few, rather large and shining, suranal plate being the largest. Sculpture: Ambulacra, interambulacra, and apical plates more or less deeply depressed. Tubercles: Not crenulated. Peristome: Naked except buccal plates, only sometimes a few plates outside the buccal plates.

272 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B1

B2

B3

C

B4

D

E1

E2

E3

Fig. 4.177: (A, B) Trigonocidaris monolini. (A) Aboral side of test, diameter 13 mm; Celebes, Indonesia. ZMUC. Two parallel series of primary tubercles are distinct. (B1) Ambulacral plates. (B2) Interambulacral plates of aboral side. (B3) Interambulacral plates of oral side. (4) Apical disc. (C–E) Trigonocidaris nitidus. (C) Aboral side of test, diameter 14 mm; Agulhas Bank, South Africa. MfN Berlin. This specimen shows several pores in each genital plate, but that is not a typical feature. (D) Side view: the test is lowly domed. (E1) Ambulacral plates. (E2) Interambulacral plates. (E3) Apical disc. Scales: (B, E) 2 mm (Mortensen 1943).

Distribution: Known from the Agulhas Bank, off South Africa. Depth ca. 500 m. Trigonocidaris radiata Mortensen, 1942 Mortensen reported on only two small specimens: largest 8 mm in diameter and with gonopores. Test: Hemispherical, not flattened above.

Apical system: Each genital plate set with a single tubercle at the periproctal edge. Sculpture: On apical plates shallow radiating furrows from the tubercles toward ocular plates. Color: Oral spines with a distinct red band in the middle, aboral spines may have a distinct red band distally: test with green or brownish stripe along the interambulacra

4.2.9 Order Camarodonta Jackson, 1912 



A

 273

C

B1

B2

B3

E

F

Fig. 4.178: (A, B) Trigonocidaris sculptus. (A) Aboral side of test, diameter 8.5 mm; Bono-Misaki, south Japan. ZMUC. The apical plates are only shallowly sculptured. (B1) Interambulacral plates. (B2) Ambulacral plates. Scale: 1 mm. (B3) Apical system. (C) Trigonocidaris versicolor. Aboral side partly with spines, diameter 14 mm; Andaman Islands. ZMUC ECH 329. Scales: (B1, B3) 2 mm; (B2) 1 mm (Mortensen 1943).

median area, in ambulacra less distinct; apical plates are distally light greenish or brown. Occurrence: Kei Islands, Indonesia. Depth 300 m. Trigonocidaris sculptus Mortensen, 1942 (Fig. 4.178 A, B) Test: Maximum recorded diameter 8.5 mm. Apical system: Each genital plate wit a single tubercles. Sculpture: Apical plates with shallow depressions or smooth; on the test forming more or less distinct horizontal grooves crossing the median suture and connecting the primary tubercles. Primary tubercles: In ambulacra and interambulacra in regular vertical series, secondaries small. Peristome: More or less naked outside the buccal plates.

Spines: Primaries not exceeding half the diameter, sparsely serrated. Color: Test and spines are pure white. Distribution: Mortensen (1943) recorded the species from Japan and Hawaii, at 400 to 510 m. Trigonocidaris versicolor Koehler, 1927 (Fig. 4.178 C) Test: Maximum diameter 14 mm. Color: The median spaces in ambulacra and interambulacra are light brownish to orange; the apical plates are olive green, the periproctal plates more brownish. Distribution: Known only from off the Andaman Islands in the Indian Ocean at a depth of 160 to 180 m. Remark: This species is closely related to T. micropora. Both differ in the size of their pores; in T. micropora, they are tiny; in T. versicolor, relatively large.

274 

 4.2 Subclass Euechinoidea Bronn, 1860

Infraorder Echinidea Kroh & Smith, 2010 The five families in this infraorder (former order Echinoida) are distinguished mainly by the number or shape of the valves of the globiferous pedicellariae and by the skeletal structure of the larvae. Simplified, the families are characterized by the following morphological features: Echinidae: The interambulacral plates are mostly covered with relatively sparse or reduced tubercles, often the surface of the test is nevertheless densely and finely granulated. The 3 pore pairs are arranged in steep arcs or as a vertical band. The buccal notches are faintly developed. Echinometridae: About half the genera have a more or less elongated test, the others are round, resembling those of the other families. The buccal notches are distinct. Parechinidae: The interambulacral plates are densely tuberculated with multiple tubercles of subequal size. The arrangement of the ambulacral pore pairs is variable. The buccal notches are faintly developed. Strongylocentrotidae: In all genera, the ambulacra are polygeminate; there are more than 3 pore pairs. They are arranged in distinctive sickle-shaped arcs. The buccal notches are generally faintly developed. Toxopneustidae: Generally, there are 3 pore pairs per plate; in a few species, up to 5 pore pairs. They are arranged in a single band or three vertical series. Deep and sharp buccal notches are characteristic for this family.

4.2.9.4 Family Echinidae Gray, 1825 The family contains six recent genera: Dermechinus Mortensen, 1942. Monospecific. Echinus Linné, 1758. Nine species. Gracilechinus Fell & Pawson, in Moore, 1966. Eight species. Polyechinus Mortensen, 1942. Monospecific. Sterechinus Koehler, 1901. Several species living in Antarctic and sub-Antarctic waters. Stirechinus Desor, 1856. A single species, closely related to Gracilechinus. Genus Dermechinus Mortensen, 1942 The monospecific genus is characterized by its high and often egg-shaped test and its distribution in all southern cold-water oceans.

Dermechinus horridus A. Agassiz, 1879 (Fig. 4.179) Test: Globular, often higher than broad, generally 80–90 mm in diameter, may reach 110 mm, maximum height 130 mm; oral side flattened. Apical system: Genital plates expanding into interambulacra; ocular plates small and exsert. Ambulacra: Primary tubercles in two regular series, slightly smaller than interambulacral ones, remaining space densely covered by small miliary tubercles; pore pairs small and inconspicuous, three per plate, pore zones slightly depressed. Interambulacra: Two regular series of primary tubercles, slightly larger than ambulacral ones, but absolutely still small; a few distinctly smaller secondary tubercles in fairly regular horizontal rows; dense miliary tuberculation. Peristome: Very small, only 10–14 % of test diameter, ­distinctly sunken; buccal plates naked. Spines: Primaries long and slender, length about 30 mm, of similar length from peristome to apical disc, much longer than secondary spines and the dense coat of miliary spines, secondaries fine, set with thorns, and ending in a hook. Color: The test is more or less intensely red or orange red, the pore zones, and the adjacent parts of the interambulacra more or less whitish. The spines, especially the primary ones, are conspiciously red. Distribution: This species is known from all southern continents: southern America, off South Africa, South Australia and Tasmania, around New Zealand, and from Subantarctic waters. It is recorded from depths of approximately 30 to 1,200 m. Biology: On the Echinoderm Conference in Brussels, Anderson et  al. (2012) illustrated the rather remarkable features of Dermechinus: a high, vertically elongated test connected with a very small peristome and lantern, which takes only one hundredth of the entire body volume; in other “regulars”, the teeth reach about one fifth to one third of it. That means the animal seems to take only a restricted amount of its food by means of his lantern. Fell (1975) already proposed that this species could be a filter feeder. The primary spines stick out like long needles, whereas the short secondaries cover the whole test with a felt-like coat. Novel deep-sea photographic and video observations support this hypothesis: the sea urchins prefer elevated ridges, they form series perpendicular to the prevailing current, and the orientation of individual specimens resemble that of other co-occurring filter-feeder organisms. Literature: Fell 1976 (unpublished PhD thesis); Tracey et al. 2011; Andersen et al. 2012.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 275

B

D

Fig. 4.179: (A–D) Dermechinus horridus. Aggregation of specimens on a seamount off Saldanha Bay, South Africa. Depth 329 m (photo by J. Schauer, Max-Planck-Institute, submarine Jago). (B) Side view of test, diameter 101 mm, height 115 mm; Scotia Sea, sub-Antarctic. ZMH. The primary tubercles in the interambulacra are regular, except on the uppermost plates, whereas in the ambulacra they are irregularly spaced. The secondaries are much smaller. (C) Aboral side: adapically the primary tubercles are very sparsely distributed. (D) Oral side: the peristome is very small and conspicuously sunken.

Genus Echinus Linné, 1758 The genus is distributed in temperate water in all oceans, mostly in deeper water and down to the bathyal zone. Remark: Mortensen (1943) listed 17 species of Echinus. Fell & Pawson (1966) established the genus Gracilechinus for those species with primary tubercles on each compound ambulacral plate. The genus Echinus is now restricted to those species with the primary tubercles irregularly set on every second or third ambulacral plate. (Fig. 4.180) Test: More or less inflated or subconical.

Apical system: Dicyclic; madreporite enlarged. Ambulacra: 3 pore pairs per plate in oblique arcs, broad pore zones forming a continuous band from peristome to apical disc; somewhat irregular primary tubercle on every second or third plate. Interambulacra: One central primary tubercle, more or less larger than the numerous secondaries. Peristome: Buccal notches indistinct. The genus consists of nine extant species: Echinus anchistus H. L. Clark, 1912. Chile. Echinus esculentus Linné, 1758. Northeast Atlantic.

276 

 4.2 Subclass Euechinoidea Bronn, 1860

Echinus euryporus H. L. Clark, 1912. Off southern Chile. Echinus gilchristi Bell, 1904. South Africa. Echinus melo Lamarck, 1816. Atlantic and Mediterranean. Echinus multidentatus H. L. Clark, 1925. Kermadec Island and New Zealand, Tasman Sea, southeast Australia. Echinus tenuispinus Norman, 1868. Faroes to Ireland. Echinus tylodes H. L. Clark, 1912. West Atlantic. Echinus wallisi A. Agassiz, 1880. West Atlantic. Literature: Mortensen 1903, 1943; Döderlein 1906; Clark, HL 1923; Fell & Pawson 1966; McKnight 1968, 1975; Shigei 1986; Rowe & Gates 1995; Kroh & Smith 2010.

low; with more or less flattened oral side; peristome not sunken; all coronal plates finely granulated; diameter up to 200 mm. Apical system: Madreporite enlarged, plates covered with tubercles of different size, this being more pronounced in larger specimens; periproctal plates also tuberculated. Ambulacra: 3 pore pairs in strongly oblique rows; primary tubercles only on every second or third plate, as large as interambulacral ones; secondaries of same size, irregularly arranged. Interambulacra: With two regular series of primary tubercles positioned centrally in each column, but difficult to recognize, virtually undifferentiated in size from the numerous, irregularly distributed secondary tubercles, not at all forming horizontal rows. Peristome: Often pentagonal; buccal notches rather inconspicuous; buccal plates with small tubercles. Spines: Uniformly short and solid with blunt tip. Color: The test is uniformly red to dark purplish red, however, sometimes with lighter or white radiating stripes; oral side much paler or whitish. The tubercles are very conspicuously white. The spines are red to red purple, distally darker, but white at the very point, sometimes they may be more or less entirely white. Distribution: This species is recorded from northern Norway and Iceland to the coasts of Portugal, including the English Channel, North Sea, and Skagerak, but it is not found in the Mediterranean. It lives from the littoral zone among algae on rocks, down to a depth of 40  m, rarely below 100 m. Biology: Echinus esculentus is an omnivore, preferring hardgrounds to graze on. The animal feeds on algae and hydroids, salpes, barnacles, even tube worms. It may reach an age of 7–8  years (Mortensen 1927). It is harvested in

Echinus anchistus H. L. Clark, 1912 Test: Very low, 50–40 % of diameter or less; largest recorded diameter 23 mm. Apical system: Genital and ocular plates with many small tubercles; periproct with relatively few plates, suranal plate very conspicuous. Ambulacra: Pore pairs small and in erect arcs; poriferous zones narrow, particularly at the peristome; at and below ambitus, well tuberculated with secondary and miliary tubercles, aborally rather bare. Interambulacra: Tuberculation well-developed subambitally, less so on the aboral side like in ambulacra. Peristome: No spines on buccal plates. Spines: Slender and fragile; half the length of test diameter. Color: The test is a dirty yellowish or pale buff, the primary and secondary spines are white, as well as the periproctal plates. Distribution: The species is restricted to southern Chile. Bathymetric range 1,890 to 2,415 m. Echinus esculentus Linné, 1758 (Fig. 4.180 A, B, 4.181) Test: Solid, usually more or less globular, sometimes high hemispherical, more rarely conical or even rather

A

B

C

D

Fig. 4.180: (A, B) Echinus esculentus, ambulacral plates. (A) Aboral side. (B) Peristomial edge. Primary tubercles occur on every second plate (shaded). (C, D) Gracilechinus elegans, ambulacral plates. (C) Aboral side. (D) Peristomial edge. Each plate is set with one primary tubercle. Scales: (A) 6 mm; (B) 4 mm (Mortensen 1943).

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 277

B

D

Fig. 4.181: (A–D) Echinus esculentus. (A) Aboral side of test, diameter 85 mm; Helgoland, North Sea, Germany. The ambulacra are narrow, the pore zones forming a band of pore pairs. (B) Side view: with a height of 81 mm, the test is almost as high as its diameter. (C) Oral side: the buccal notches at the edge of the pentagonal peristome are inconspicuous. (D) Aboral side, diameter with spines 96 mm; Skagerak, southwest Sweden.

western Europe (name: esculentus = “edible sea urchin”), the gonads are thought to be a delicacy. Remarks: Echinus esculentus is immediately distinguishable from Paracentrotus lividus and Psammechinus miliaris by its size and the red color, the others being green or dark purplish. Sphaerechinus granularis differs in having 4 or 5 pore pairs in one arc and deep buccal notches and the spines are purplish with conspicuous white tips.

Echinus euryporus H. L. Clark, 1912 Test: Highly inflated, holotype in diameter 46 mm. Apical system: Genital and ocular plates well tuberculated; periproct covered by small, slightly swollen plates, suranal plate distinct. Ambulacra: Poriferous zones moderately broad ambitally, at the peristome becoming widened and broader than interporifeous zone, pore pairs in quite oblique rows, adorally almost horizontal; primary tubercles of irregular size and distribution.

278 

 4.2 Subclass Euechinoidea Bronn, 1860

Interambulacra: Plates ambitally well tuberculated, beside the primary tubercles 8–12 secondaries and 50–60 miliaries. All tubercles elevated, giving the surface a rough appearance. Peristome: Not sunken. Spines: Primaries about 20–25 mm in length, slender and tapering; secondaries much smaller and very slender. Color: Test light purplish brown, lightest along the poriferous zones and the interambulacral median areas. Oral side rather whitish. The spines are light red brown. Distribution: The holotype was found off the South Chilean coast at a depth of 315  m. It is likely that this species lives on seamounts in the southeastern Pacific.

A

C

Remark: This species differs from Echinus anchistus by the widened pore zones on the oral side. Echinus gilchristi Bell, 1904 (Fig. 4.182) Test: Low hemispherical, subconical or rather highly domed; peristome hardly sunken; test diameter up to 84 mm. Apical system: All plates, genital, ocular, and periproctal ones, densely tuberculated; opening of anus eccentric. Ambulacra: With 3 pore pairs on each plate; primary tubercles often confined to the ambitus and to the oral side; on the aboral side, there are only small tubercles, but there may also be small and larger tubercles alternating more

B

D

Fig. 4.182: (A–D) Echinus gilchristi. (A) Aboral side of test, diameter 55 mm; off Cape Point, South Africa. The surface is sparsely tuberculated, there are only a few larger primary tubercles. (B) Close-up of ambulacrum and interambulacrum: the primary tubercles are irregularly distributed or on every second plate. Scale: 10 mm. (C) Side view, diameter with spines 100 mm; off Cape Point, South Africa. The few primary spines are much longer than the others, which form a short, dense coat. The entire surface is covered by small pedicellariae with globular heads. (D) Close-up of the peristome. The mouth with the teeth, encircled by the lip, is surrounded by a very dense band of pedicellariae, which support food intake.



or less regularly; between the larger tubercles the plates are more or less densely covered by very small tubercles, leaving only a narrow, naked median line, sometimes with growth lines. Interambulacra: Primary tubercles mostly irregularly developed, sometimes alternating on each and every second plate; enlarged secondary tubercles usually restricted to the oral side; remaining space covered by very small miliary tubercles, narrow median zone naked, often with distinct growth lines. Peristome: Small, but distinct buccal notches, buccal membrane with a few small, scattered plates, buccal plates rather large, covered by numerous pedicellariae. Spines: Long primary spines among a dense coat of very small spines; below the ambitus, the spines are flattened and widened distally. Color: Usually, it is a dull whitish or light leather brown, the oral side is lighter. The primary spines are white, on the oral side sometimes with a narrow red band at the base; the small spines darker, sometimes tending to greenish. The cleaned test is light greenish, rarely red brown, with white tubercles and conspicuous lines at the median sutures. Sometimes, there is a distinct whitish space along the interambulacral horizontal sutures giving the series of plates a somewhat ladder-like appearance. Distribution: Echinus gilchristi is restricted to South Africa, from off Saldanha Bay on the Atlantic coast round the Cape to off East London in the Indian Ocean. It lives at depths of 40 to 500 m. Remarks: This species resembles Echinus melo from the Mediterranean, but differs in having larger tubercles among the primary ones. Echinus melo looks almost naked except for the primaries, and the growth lines and the lozenge-shaped patterns are more distinct than in E. gilchristi. Echinus melo Lamarck, 1816 (Fig. 4.183 A, B) Test: Globular, hardly flattened on the oral side; diameter may reach 140 mm; all coronal plates with tiny granules. Apical system: Prominent madreporite. Ambulacra: Pore pairs in arcs of three, rather far from the outer side of the plates, primary tubercles rather small; secondaries still smaller, scarce, and irregular; narrow median zones naked and with growth lines. Interambulacra: Small primary tubercles in the middle of every second plate, sparse secondaries much smaller; median zone naked and with distinct growth lines; horizontal sutures with lozenge-shaped pattern. Peristome: Small, not sunken, buccal notches indistinct.

4.2.9 Order Camarodonta Jackson, 1912 

 279

Spines: Primary spines slender, much longer than the secondary spines. Color: The test is yellowish brown or greenish, the median lines and the lozenge-shaped spaces in the interambulacra are lighter. The spines are mostly a light uniform green, rarely light red brown, sometimes the primary spines may be darker than the smaller ones. Biology: This species is likely to live on hard and rocky bottoms. Distribution: Echinus melo is known from the western Mediterranean as far east as the Adriatic. In the Atlantic, it is reported from off Ireland to Portugal, along West Africa southward to the Cape Verdes and from the Canaries to the Azores. It lives at depths of 25 to 1,100 m. Remarks: Echinus melo is distinguished from Echinus gilchristi by its globular test, its yellowish greenish color and the fewer tubercles. Echinus esculentus differs from Echinus melo by its more or less uniform dark red color and by the numerous equal-sized secondary tubercles. Echinus multidentatus H. L. Clark, 1925 (Fig. 4.183 C, D) Test: More or less flattened aborally, distinctly flat on oral side; growing to a large size (McKnight 1968 reported a maximum diameter of test of 97 mm). Apical system: All plates with small tubercles, madreporite conspicuous; periproctal membrane with small plates, anal opening eccentric. Ambulacra: 3 pore pairs per plate in steep arcs; primary tubercles very irregularly distributed, on the aboral side usually on every second or third plate (or up to sixth according to McKnight), with scattered secondaries and miliaries leaving the median area rather bare; on oral side, primary tubercles more regular decreasing in size toward the peristome, small tubercles more numerous. Interambulacra: One primary tubercles per plate forming a distinct row, secondaries and miliaries scattered with bare median area; ambitally and subambitally rows of secondaries on either side of primary tubercles. On the whole, the test looks rather naked aborally with its distantly spaced larger tubercles; however, the remainder of the surface is covered by numerous very small granules. Primary spines: Up to 35 mm in length above the ambitus, subambitally shorter. Color: Test and spines pale cream, pale pink or dull light brown to straw colored. Remark: According to McKnight (1968), this species shows much variation in number and distribution of spines and in the shape of the test. In some specimens, the rows of

280 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

Fig. 4.183: (A, B) Echinus melo. Aboral side of test, diameter 80 mm, height 67 mm; Malaga, southern Spain. Very few primary spines are developed aborally. (B) Side view: the median zones are naked and set with conspicuous growth lines. Lozenge-shaped patterning is visible along the horizontal sutures. (C, D) Echinus multidentatus. Aboral side of young specimen, diameter of test 9.5 mm; east of New Zealand at a depth of 1,892 m. MfN Berlin. The surface of the test is set by a few primary tubercles, secondary tubercles and small granules are almost totally lacking. (D) Oral side.

tubercles on adjacent plate series in the aboral ambulacra may be completely different: the one may consist mainly of larger tubercles and the other is formed almost exclusively of small tubercles. Occurrence: The species is reported from the Kermadec Islands, the Tasman Sea, and off southeastern Australia and northern New Zealand. Bathymetric range about 510 to 1,900 m.

Echinus tenuispinus Norman, 1868 The species is very closely related to Echinus esculentus with its globular test and the small spines on the buccal plates. Largest recorded test diameter 57 mm (Mortensen 1927). It differs by the much fewer secondary tubercles aborally, among which the primaries are very distinct and by the white color.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

 281

C

40 mm 40 mm

40 mm

Fig. 4.184: Gracilechinus: ambulacral plates (left) and interambulacral plates (right). (A) Gracilechinus affinis. (B) Gracilechinus alexandri. (C) Gracilechinus elegans (Mortensen 1903).

Distribution: Northeast Atlantic, Faroes to Ireland, mostly on the Porcupine Bank at depth of 130–200. Echinus tylodes H. L. Clark, 1912 Test: Well arched, thick, and rough, of medium to large size, holotype 57 mm. Apical system: All plates swollen being set with only very few tubercles; periproctal plates rounded, suranal plate hardly distinguishable. Ambulacra: Large pore pairs, poriferous zones rather broad and slightly widening adorally, the rows oblique, becoming almost horizontal at the peristomial edge. Ambulacra and interambulacra: Each coronal plate set with a primary tubercle, regularly diminish toward the apical system and the peristome, being connected by a faint vertical ridge, more distinct in ambulacra than in interambulacra, more distinct aborally; secondary and miliary tubercles not very numerous, but conspicuously elevated giving the plates a rough surface. Peristome: Buccal plates without tubercles; buccal notches broad and very shallow. Spines: Rather short (in holotype only 18 mm). Color: The test is a light reddish buff, in young specimens almost white; the spines are pale red, in younger brighter. Distribution: Found along the east coast of the USA from off Martha’s Vineyard to the Gulf of Mexico. Bathymetric range 230 to 794 m. Echinus wallisi A. Agassiz, 1880 Test: Low hemispherical, stout and rough with elevated tubercles and depressed sutures; diameter may reach 100 mm. Apical system: Larger than peristome; all plates slightly swollen; periproct large with numerous small plates, suranal plate distinct.

Ambulacra: Primary tubercles smaller than in interambulacra; on the aboral side of irregular size and lacking on alternate plates, at and below ambitus on each plate; pore zones quite broad. Spines: In length about half the diameter of test, secondaries much smaller, about 12 mm and very slender. Color: The living specimens show a brilliant dark red, spines somewhat lighter being darkest at the base and pinkish at the tip. Distribution: West Atlantic from Cape Cod, Massachusetts, to Georgia, USA, at depths of 460 to 1,885 m. Genus Gracilechinus Fell & Pawson, in Moore, 1966 This genus is very similar to Echinus. It differs in having usually each ambulacral plate set with a primary tubercle, although they may be of irregular size. (Fig. 4.180) Test: Very variable from more or less highly hemispherical to subconical. Apical system: Dicyclic with ocular plates exsert. Ambulacra: 3 pore pairs in oblique arcs forming a uniform band from apex to peristome. Interambulacra: Small central primary tubercle differentiated from secondaries, arranged in fairly regular series; plates more or less densely granulated. Eight extant species are included in this genus: Gracilechinus acutus Lamarck, 1816. Atlantic, Mediterranean. Gracilechinus affinis Mortensen, 1903. North Atlantic. Gracilechinus alexandri (Danielssen & Koren, 1883). North Atlantic. Gracilechinus atlanticus Mortensen, 1903. South Atlantic, off Ascension, and St. Helena. Gracilechinus elegans Düben & Koren, 1844. North Atlantic. Gracilechinus gracilis A. Agassiz, 1869. Atlantic. Gracilechinus lucidus Döderlein, 1885. Japan.

282 

 4.2 Subclass Euechinoidea Bronn, 1860

Gracilechinus stenoporus Mortensen, 1942. South Africa. The specimens often do not show clearly their typical features. Consequently, the distinction sometimes turns out to be difficult, especially between G. alexandri and G. elegans. Gracilechinus acutus Lamarck, 1816 (Fig. 4.185, 4.186) Test: Shape very variable, usually subconical, but may be high conical or even subglobular or very low and flattened; diameter up to 160 mm; coronal plates more or less granulated. Apical system: Much variation in size; madreporite slightly enlarged, periproctal plates small and numerous, opening of anus eccentric. Ambulacra: 3 pore pairs in each arc; primary tubercles irregularly on each plate or every second one; smaller secondary tubercles scarce and irregularly arranged. Interambulacra: Two series of primary tubercles, not always on every plate or not of same size aborally, smaller secondaries scarce and irregular. Peristome: Rather small, but with large variation, very slightly sunken, buccal notches small. Spines: Variable, primary spines short, but distinctly longer than secondary ones; at the ambitus they may be flattened and widened distally. Color: In general, the test shows a more or less intense red or red brown with lighter pore zones and median spaces, giving it a radiating pattern; the oral side is more or less whitish. Sometimes the test can be wholly whitish. The spines are usually dark reddish or greenish at the base, turning white distally, more rarely they may be green with a white tip, or even entirely reddish. Distribution: Echinus acutus is found in European seas from the Barents Sea and Iceland southward to Cape Bojador, West Africa, and in the Mediterranean at depths of 20 to 1,280 m. Remarks: Hybrids of Gracilechinus acutus and Echinus esculentus are common, and hybridization can even occur between G. acutus and Psammechinus miliaris. Due to the large variation shown by this species, three varieties have been nominated, but because intermediates also occur, it is often difficult and therefore useless to separate them. The geographic distribution of these varying forms is not restricted according to their names, which means G. acutus var. norwegicus may also occur in the Bay of Biskay or the Mediterranean etc. Literature: Mortensen 1927. Gracilechinus affinis Mortensen, 1903 (Fig. 4.184 A, 4. 187) Test: Low, regularly arched or subconical; diameter reaches only 51 mm; outline round or subpentagonal.

Apical system: Generally somewhat raised; a few tubercles on genital plates, none or only one on ocular plates; periproctal plates small and numerous, mostly with no distinct suranal plate. Ambulacra: Primary tubercles on every compound plate, conspicuously irregular in size, largest primary tubercle not much smaller than on interambulacra, few secondaries on oral side, almost none aborally; arcs of pore pairs rather erect. Interambulacra: Primary tubercles large and robust, reaching up to the apical disc; areoles confluent orally, more distant aborally; very few secondary tubercles on upper side, much more on oral side and distinctly smaller; miliary usually not numerous; aboral side in the whole rather naked. Peristome: 28–36 % of test diameter of 30–50  mm; numerous very small plates beside the buccal plates. Spines: Up to 22 mm in length, robust. Color: In general, with a greenish or purplish tint; spines light to green or with purplish base. Distribution: Northern Atlantic from Ireland to the Denmark Strait and along the east coast of the USA to the Azores, 770 to 2,230 m. Remarks: Gracilechinus affinis is often found together with G. alexandri. Gracilechinus alexandri Danielssen & Koren, 1883 (Fig. 4.184 B, 4.188 A, B) Test: Flattened below and usually also above, height less than half the diameter; maximum diameter 86 mm. Apical system: Inner part of genital plates well tuberculated, distally naked; gonopores often double; periproct larger than madreporite (compare with G. elegans), with very numerous, tiny plates, suranal plate more or less differentiated. Ambulacra: Primary tubercles regular in size, on oral side areoles confluent, on aboral side tubercles much smaller; around the ambitus series of even smaller secondary tubercles inside the primaries; numerous miliary tubercles orally, much fewer aborally; pore pairs rather erect; forming a vertical band. Interambulacra: Regular series of primary tubercles, only in smaller specimens decreasing in size; on oral side, slightly smaller and with secondaries, aborally sparse and with only a few miliary tubercles; on the whole, the aboral side rather naked. Peristome: Numerous large plates, no spines on buccal plates, indistinct notches. Spines: Very brittle, often broken and regenerated; length highly variable, may reach the diameter of test, or only half the diameter; on oral side widened and flattened at the point.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 283

B

E

D

Fig. 4.185: (A–E) Gracilechinus acutus. (A) Aboral side of test, diameter 73 mm; Adriatic Sea, Mediterranean. (B) Oral side: on the upper side the secondary tubercles are sparsely distributed, the oral side is more densely tuberculated. (C) Side view of test, diameter 69 mm; Iceland. (D) Close-up of aboral side: the primary tubercles on the ambulacra are irregularly arranged. Scale: 10 mm. (E) Echinus acutus. Aboral side with spines, diameter 95 mm; southern France. ZMH The greenish white spines have a dark base and sometimes a dark tip.

Color: In life, the test is light rose carmine, in preserved specimens white. The spines are light yellowish beige with darker tips. Distribution: North Atlantic, Faeroes Channel to Iceland, and the Denmark Strait; only exceptionally off Norway

and Lofoten; east coast of the USA, Azores, probably Tristan da Cunha, 365 to 3,120 m. Remarks: This species often occurs with G. affinis, from which it differs mainly by the arrangement of the ambulacral tubercles, in G. alexandri, they are regular; in G. affinis,

284 

A

 4.2 Subclass Euechinoidea Bronn, 1860

C

B

D

E

Fig. 4.186: (A) Gracilechinus acutus. Typical subconical form. Diameter of test 104 mm; Iceland. (B) Gracilechinus acutus “norvegicus”. Side view with some spines, diameter of test 61 mm; west of Ireland. The test is rather low and bright red. (C) Gracilechinus acutus “norvegicus”. Aboral side with spines, diameter of test 44 mm; west of Ireland. The naked interambulacral mid-areas are conspicuously red. (D) Gracilechinus acutus “mediterranea”. Side view of test, diameter 101 mm; Savona, Ligurian Sea, northern Italy. (E) Gracilechinus acutus “flemingi”. Side view with spines, diameter of test 98 mm; Plymouth, England. ZMUC. The aboral side is broadly rounded.

they are irregular in size. From G. elegans, this species is distinguished by the less tuberculated upper side and by the larger periproct. Gracilechinus atlanticus Mortensen, 1903 (Fig. 4.188 C–E) Test: Very thin and fragile; regularly hemispherical, flattened below, not sunken toward the peristome; maximum recorded diameter 88 mm. Apical system: Very bare, genital plates with only 1 tubercle.

Ambulacra: Pores rather small, arcs of pore pairs steep, crowded toward the peristomial edge; usually a single primary tubercle per plate, aborally small, slightly larger, and irregular in size on oral side; secondary tubercles almost totally lacking, on oral side very scarce. Interambulacra: Conspicuous primary tubercles, only faintly decreasing in size adapically; positioned in the center of the rather high plates and distant from each other; on the whole, the aboral side is very bare with growth lines sometimes being visible.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 285

B

D

Fig. 4.187: (A-C) Gracilechinus affinis. (A) Aboral side, diameter 49 mm; off Long Island, USA. ZMUC. (B) Oral side. (C) Side view: the interrupted rows of ambulacral tubercles are very typical. (D) Gracilechinus affinis. Side view with spines. diameter of test 38 mm; Greenland. ZMUC. The test is rather low. Most of the primary spines are more or less broken.

Spines: Primaries rather coarse, in length about half the diameter of test. Color: The spines are more or less intensely red with white distally. The test is white with a more or less reddish tinge along the primary tubercles and on the genital plates. Distribution: The typical Gracilechinus atlanticus is restricted to Ascension in the southern Atlantic known from a depth of about 750  m. A variety occurs off St. Helena at a depth of 375 to 520 m. Gracilechinus elegans Düben & Koren, 1844 (Fig. 4.180 C, 4.184 C, 4.189) Test: Shape highly variable, low hemispherical, more or less high, subconical or flattened; in diameter up to 97 mm. Apical system: Plates tuberculated only on inner part, distally being naked; periproct rather small, not much smaller than madreporite; small periproctal plates, suranal plate recognizable.

Ambulacra: Primary tubercles large and robust, in very regular series, smaller than interambulacral ones, areoles confluent, secondaries on oral side fairly regular, on upper side only a few; numerous miliary tubercles; arcs of pore pairs rather erect. Interambulacra: Primary tubercles strong, only on oral side confluent, secondary tubercles numerous orally, smaller on upper side, many miliary tubercles; all tubercles elevated, giving the denuded test a rough appearance. Peristome: Numerous plates, buccal notches indistinct. Spines: Rather solid, in length half to two thirds of test diameter. Color: Spines red with white tips, but may be also creamy or entirely yellowish white; denuded test with red aborally, pore zones white; the test may be also pure white to yellowish. Distribution: From Lofoten, Norway, to the Skagerrak, from south of Iceland to the Bay of Biscay, eastern USA, to

286 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

E

Fig. 4.188: (A, B) Gracilechinus alexandri. (A) Aboral side of test, diameter 81 mm; Iceland. ZMUC. (B) Side view. (C–E) Gracilechinus atlanticus. (C) Aboral side of test, diameter 51 mm; Ascension, South Atlantic. ZMUC. Secondary tubercles are almost totally lacking. (D) Oral side: the test is hardly sunken toward the peristome. (E) Side view.

the Azores, and along the West African coast. Bathymetric range ca. 50 to 1,710 m. Remarks: This species differs from G. affinis by the ambulacral primary tubercles being very regular; in the latter, the ambulacral tubercles are of different sizes. From G. alexandri, it is distinguished by the more densely set miliary tubercles aborally, by the smaller periproct and by the test usually not being flattened above, but variably subconical or even high.

Gracilechinus gracilis A. Agassiz, 1869 (Fig. 4.190) Test: Regularly hemispherical or subglobular, orally flattened, diameter can reach more than 88 mm. Apical system: Genital plates with several larger tubercles, distal part remaining naked; few and relatively large periproctal plates, some of which carrying a tubercle. Ambulacra: Primary tubercles in regular series, almost same size from peristome to apical disc; secondary tubercles

4.2.9 Order Camarodonta Jackson, 1912 



A

 287

B

C

Fig. 4.189: Gracilechinus elegans. (A) Aboral side of test, diameter 56 mm; Trondheimfjord, Norway. ZMUC. (B) Side view. (C) Oral side. The tests are not often as beautiful as this specimen.

A

B

C

Fig. 4.190: Gracilechinus gracilis. (A) Aboral side of test, diameter 45 mm; Florida, USA. ZMUC ECH 187. (B) Oral side. (C) Side view. The lozenge-shaped pattern is also visible below the spines.

288 

 4.2 Subclass Euechinoidea Bronn, 1860

well developed but irregular; pore zones rather broad, arcs of pore pairs oblique. Interambulacra: Primary tubercles rather small, of same size on aboral and oral side, smaller secondaries in fairly regular series. Peristome: Buccal plates without tubercles; membrane with numerous delicate plates, but looking naked. Spines: Hardly exceeding 20 mm, forming a more or less uniform coat. Color: Spines white or light brownish distally, test in the main green with white lozenge-shaped areas below each interambulacral primary tubercle; tubercles themselves and pore zones white giving the aboral side a radiating pattern well visible also below the spines; oral side whitish toward the peristome. Distribution: East coast of North America and Gulf of Mexico from Martha’s Vineyard, USA, to off Cuba, 120 to 445 m.

A

C

Gracilechinus lucidus Döderlein, 1885 (Fig. 4.191 A–C) Test: Low hemispherical, oral side slightly sunken; diameter hardly reaching 50 mm. Apical system: Genital plates at periproctal edge distinctly raised; a few tubercles on the inner part, distal part naked; periproctal plates uniform in size, around the eccentric anal opening papilliform; small but distinct subanal plate. Ambulacra: Pore pairs in steep arcs; primary tubercles irregular in size, small aborally, from ambitus to oral side larger and secondaries in short vertical series, miliaries scarce; aboral median areas rather naked. Interambulacrum: Primary tubercles distinctly larger than on ambulacra, in regular series; secondaries small, mainly developed on oral side, few miliaries, naked median areas. Peristome: Buccal plates without tubercles. Spines: Fragile, in length barely reaching test diameter, ending in a simple point.

B

D

E

Fig. 4.191: (A–C) Gracilechinus lucidus. (A) Aboral side with spines, just after being dredged, test diameter 47 mm; Shizuoka, Japan (photo by Takashi Ito). (B) Aboral side of same specimen, denuded. (C) Oral side. (D, E) Gracilechinus stenoporus. (D) Aboral side with some remaining and broken spines, diameter of test 42 mm; South Africa. ZMUC ECH 298. (E) Oral side.

4.2.9 Order Camarodonta Jackson, 1912 



Color: Spines are whitish or brownish with white bases, test grayish pink, darker anal system; spine muscles pinkish; denuded test white. Distribution: Restricted to Japanese seas from off northern Honshu to Okinawa, 180 to 1,750 m. Gracilechinus stenoporus Mortensen, 1942 (Fig. 4.191 D, E) Test: Low, subconical, horizontal diameter up to 42 mm. Apical system: Genital plates with 1 to 3 tubercles along the inner part, numerous periproctal plates, suranal plate small but remains distinct. Ambulacra: Primary tubercles of different sizes, lacking on the uppermost plates; steep arcs of pore pairs. Interambulacra: Primary tubercles rather large and in regular vertical series, standing on a more or less distinct ridge, secondaries poorly developed also on the oral side, the upper surface being almost naked, median area bare.

A

C

 289

Color: Spines white with a faint brownish tint basally; test creamy, white when well cleaned. Distribution: South Africa, deep sea. Genus Polyechinus Mortensen, 1942 This monospecific genus is distinguished from Echinus and Gracilechinus by its polygeminate ambulacra: there are usually 4 pore pairs per compound plate, more rarely 3 or 5. Polyechinus agulhensis Döderlein, 1905 (Fig. 4.192) Test: Highly variable, from almost globular to low hemispherical and even flattened; diameter up to 80 mm. Apical system: A few tubercles around the inner part of the genital plates, distally smooth; genital pores small, madreporite inflated; large periproct with numerous small plates, suranal plate hardly recognizable.

B

D

E

Fig. 4.192: (A–E) Polyechinus agulhensis. (A) Aboral side of test, partly with spines, diameter 76 mm; South Africa. ZMUC. (B) Oral side. (C) Side view: there are 4 pore pairs in an arc. (D) Apical system. (E) Ambulacral plates. Scales: (D) 6 mm; (E) 8 mm (Mortensen 1943).

290 

 4.2 Subclass Euechinoidea Bronn, 1860

Ambulacra: Pore pairs in arcs of four, sometimes there may be 5 or 3 pore pairs in an arc. Primary tubercles regular, half the size of interambulacral ones, secondaries not in vertical series, numerous miliaries, naked median space. Interambulacra: Primary tubercles rather large, barely decreasing in size aborally, wide areole confluent only on oral side, secondary tubercles small and scattered; miliary tubercles more or less densely spread, naked median line. Peristome: Vary in size, sometimes larger than apical disc, sometimes distinctly smaller. Spines: Primaries stout but brittle. Color: Brown; cleaned test and spines white. Distribution: Found only around the Cape Province, South Africa, at depths of 200 to 1,080 m. Genus Sterechinus Koehler, 1901 The genus is characterized by a conspicuously large periproct within a ring of low apical plates. The membrane is covered by numerous small plates and an additional distinct suranal plate. The six closely related and very similar species occur around the Antarctic continent and the Subantarctic islands extending to temperate waters. They have a wide bathymetric distribution ranging from the littoral to the bathyal. Biology: The species of Sterechinus are the only group of Antarctic sea urchins, which develop through a larval stage and metamorphosis, the cidarids and the irregular schizasterids (vol. II.) being brood-protecting. The larvae of Sterechinus neumayeri have a development time of up to four months. They may remain in the free water for up to a year feeding plankton because their metabolism is extremely low. Growth is very much retarded, so that they may live as long as 75 years, reaching their maximum size at an age of about 70 years. Literature: Pearse & Giese 1966; Bosch et  al. 1987; Brey 1991; Brey & Gutt 1991; Brey et al. 1995; David et al. 2000, 2005; Jacob et al. 2003; Diaz et al. 2010; Pierrat et al. 2012. The genus was thought to consist of six species being very variable in color, position of ocular plates (insert or exsert), and shape of pedicellariae. However, the supposedly distinctive characteristics are very faint and not constant. One even cannot distinguish the species clearly by the shape of their pedicellariae. David et  al. (2000) put up for discussion that there might exist a single circum-Antarctic species with local variations. Recent phylogenetic research (Diaz et al. 2010) with more material than in former times revealed that only Sterechninus neumayeri seems to form a distinct species,

being distinguished genetically and by the shape of the pedicellariae. It is most likely that Sterechinus agassizi, Sterechinus antarcticus, Sterechinus dentifer, and Sterechinus diadema are an entity in which S. dentifer is slightly separated by the shape of its pedicellariae. Test: Low hemispherical, subconical or flattened, usually thin and of moderate size. Apical system: Relatively large due to the large periproct; dicyclic or variably with one to five oculars insert; madreporite well differentiated; all genital and ocular plates densely tuberculated; periproctal plates numerous and small, suranal plate usually distinct, anal opening eccentric. Ambulacra: 3 pore pairs in oblique arcs; primary tubercles on every second or third plate, secondary tubercles distinctly smaller, all plates densely set with very small militaries. Interambulacra: Regular series of primary tubercles; on the oral side irregularly arranged secondaries, distinctly smaller, on the upper side much smaller; all plates densely covered by tiny miliary tubercles. Peristome: Buccal membrane naked outside the buccal plates, which with some additional plates form a dense ring, usually small platelets imbedded in the membrane, plates with small tubercles. Spines: Primary spines longer and thicker than secondaries, numerous tiny miliary spines forming a dense coat; all spines extremely brittle. Color: In living specimens, the test is brown to reddish or even bright red, the primary spines are often lighter. The cleaned test is whitish to olive gray. Traditionally, the species are defined as follows: Sterechinus agassizii Mortensen, 1910. Usually test low conical. Sterechinus antarcticus Koehler, 1901. Circum-Antarctic, Scotia Sea, and northward to Argentinian shelf and North Patagonian Gulfs in Chile, dominant below 450 m. Sterechinus bernasconiae Larrain, 1975. Restricted to the southern Chilean coast. Sterechinus dentifer Koehler, 1926. Amundsen Sea, Bellingshausen Sea, Scotia Sea, Weddell Sea, to Wilkes Land, East Antarctica., deep sea. Sterechinus diadema Studer, 1876. Crozet-Prince Edward Island. Antarctic Ocean. Sterechinus neumayeri Meissner, 1900. Circum-Antarctic, Scotia Sea, Falkland Islands, Heard Island, in relatively shallow water. Sterechinus agassizi Mortensen, 1910 (Fig. 4.194 A, B) Characteristics of the genus. Test: Diameter may reach 80 mm.



4.2.9 Order Camarodonta Jackson, 1912 

 291

Sterechinus neumayeri Meissner, 1900 (Fig. 4.195 B–F) Characteristics of the genus. Test: Diameter may reach 60 mm. Sterechinus neumayeri differs genetically from the other species, being distinguished also by the shape of the pedicellariae and the absence of spicules in the tube feet. Distribution: Very common in shallow water. Lives around the Antarctic continent, along the Antarctic Peninsula and off the adjacent islands. Bathymetric range ~3 to 810 m.

Fig. 4.193: Sterechinus antarcticus. Close-up of apical system, diameter of test 53 mm; Palmer Archipelago. ZMUC. The genital and ocular plates are low due to the large periproct. The anal opening is eccentric. A small sunanal plate is clearly differentiated. Scale: 10 mm.

Distribution: This species is recorded from the Subantarctic Islands in the South Atlantic and from the Argentinean shelf northward to the mouth of the Rio de la Plata. Bathymetric range 13 to 970 m. Sterechinus antarcticus Koehler, 1901 (Fig. 4.193, 4.194 C) Characteristics of the genus. Diameter may reach 65 mm, mostly 20–50 mm. Distribution: Found around Antarctica. Bathymetric range 30 to 2000 m, but dominant below 450 m. Sterechinus bernasconiae Larrain, 1975 Main characteristics of the genus. Distribution: This species is recorded only from off the Chilean coast from north of Valparaíso (32 °S) to Estrecho de Concepción (51 °S) living in cold and temperate water. Bathymetric range 300 to 600 m. Sterechinus dentifer Koehler, 1926 (Fig. 4.194 D, E) Characteristics of the genus. Maximum diameter of test only 30 mm. Distribution: Sterechinus dentifer lives exclusively in the deep sea. It is recorded from the continental slope around Antarctica and in the depth of the Tasman Sea. Bathymetric range 1,200 to 3,930 m. Sterechinus diadema Studer, 1876 (Fig. 4.195 A) Characteristics of the genus. Test: Diameter may reach 70 mm. Distribution: This species is restricted to the Kerguelen Plateau in the South Indian Ocean. Bathymetric range 15 to 750 m.

Genus Stirechinus Desor, 1856 This monospecific genus is similar to Gracilechinus in having the ambulacral primary tubercles on every plate. It differs in having a vertical ridge linking the primary tubercles. Stirechinus tylodes H. L. Clark, 1912 (Fig. 4.196) Test: Hemispherical, not sunken adorally, diameter up to 57 mm. Apical system: Dicyclic; only very few tubercles on genital plates, a single on each ocular plate; numerous periproctal plates without any tubercles, suranal plates distinct; anal opening eccentric. Ambulacra: 3 pore pairs per plate in rather steep arcs; primary tubercles of same size from apical disc to peristome connected by a vertical ridge; secondaries slightly smaller and in vertical series. Interambulacra: Distinct vertical ridge between the primary tubercles, sutures often depressed. Peristome: Buccal membrane appears naked, but is covered by very delicate platelets. Spines: Reach a length of about 15 mm. Color: The test is white, the spines are light pink with white tips. Distribution: The species is restricted to the east coast of the USA from Georgia to Florida, 350 to 760 m.

4.2.9.5 Family Echinometridae Gray, 1825 The family Echinometridae contains some of the most specialized genera of regular echinoids. They live in the surf zones of reefs. Colobocentrotus and Podophora are adapted to these extreme habitats by evolving short aboral spines tessellated as a pavement to minimize resistance to the waves. Heterocentrotus and Zenocentrotus are equipped with long, conspicuously stout spines, longest along the major axis to wedge the test tightly between the reef blocks in heavy water motion.

292 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

E

Fig. 4.194: (A) Sterechinus agassizi. Aboral side with secondary spines, diameter of test 58 mm; South Georgia. ZMUC. The brittle primary spines are all broken. (B) Sterechinus agassizi. (B) Side view of test, diameter 47 mm; Argentinean shelf off Peninsula Valdéz. ZMUC. (C) Sterechinus antarcticus. Aboral side of test, diameter 53 mm; Palmer Archipelago. ZMUC. (D, E) Sterechinus dentifer. (D) Aboral side of test, diameter 20 mm; off Tasmania, at 1,800 to 1,820 m. ZMUC. (E) Oral side.

Thirteen genera are included in this family distributed over the whole tropical Indo-Pacific and Atlantic. Today, this family does not occur in the Mediterranean, although fossil specimens of Echinometra mathaei are found in southern France.

Nine genera and a subgenus belong to this family: Caenocentrotus H. L. Clark, 1912. Monospecific; western coast of South America. Colobocentrotus Brandt, 1835. Two subgenera with three species; Indo-Pacific.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

D

E

 293

C

F

Fig. 4.195: (A) Sterechinus diadema. Aboral side of test, diameter 68 mm; Kerguelen Islands. ZMUC. (B–F) Sterechinus neumayeri. Aboral side with secondary spines, diameter of test 47 mm; off Queen Mary Land, Antarctica. ZMUC. (C) Aboral side with some remaining primary spines, diameter of test 26 mm; eastern Weddell Sea, Antarctica. The primary spines are much longer than the dense coat of secondaries. Mostly they are broken as they are extremely brittle. (D) Aboral side of test, diameter 54 mm; South Orkney Island. ZMUC. (E) Oral side. (F) Close-up of apical system. Scale: 10 mm.

A

B

Fig. 4.196: Stirechinus tylodes. (A) Aboral side, partly with spines, diameter of test 42 mm; off northern Florida, USA. ZMUC. (B) Oral side.

294 

 4.2 Subclass Euechinoidea Bronn, 1860

Echinometra Gray, 1825. Five species; Indo-Pacific and Atlantic. Echinostrephus A. Agassiz, 1863. Two species; Indo-West Pacific. Evechinus Verrill, 1871. Monospecific; New Zealand. Heliocidaris L. Agassiz & Desor, 1846. Two species; Australia and New Zealand. Heterocentrotus Brandt, 1835. Two species; Indo-West Pacific. Selenechinus de Meijere, 1903. Monospecific; Philippines. Zenocentrotus H. L. Clark, 1931, two species; Tonga Islands. The Echinometridae are the only family of regular echinoids, in which elongated tests occur. Apparently, elongation of test has developed separately in at least two lines, which differ in the orientation of their long axis. Genus Caenocentrotus, H. L. Clark, 1912 Caenocentrotus gibbosus L. Agassiz & Desor, 1840 (Fig. 4.197) Test: Low hemispherical, circumference round or rounded pentagonal; diameter up to 70 mm. Apical system: Usually with ocular plates IV and V insert, in consequence periproct being displaced to the left. Ambulacra: 4 pore pairs to an arc, often five; pore zones broad and with secondary tubercles, not widened adorally. Interambulacra: Two series of primary tubercles, distinct rows of secondaries, many miliaries.

A

Peristome: Buccal plates naked, membrane without plates; notches inconspicuous. Spines: Stout, short, and uniform, less than half the diameter of test, slightly longer on the oral side. Color: The spines are usually green, the tip often red or reddish brown. They may also be olive green tipped with purple. The test is greenish, the pore zones, and the oral side lighter. Distribution: Caenocentrotus gibbosus is known from Guayaquil, Ecuador, along the Peruvian coast to northern Chile and from the Galapagos Islands. It is probably restricted to the littoral zone. Remarks: This species differs from Loxechinus albus by the number of pore pairs per arc, Caenocentrotus gibbosus having 4 or 5, the former 7–10 pore pairs. Biology: Almost all specimens of Caenocentrotus gibbosus are deformed aborally, caused by a parasitic crab. The juvenile crab appears to force an entrance into the periproct, where it lodges and grows in the dilated intestine. Fully grown, it is unable to leave the corona of the sea urchin, and sits with its claws protruding through the distorted anal opening. Loxechinus albus, another camarodont echinoid from the same region, often also houses the crab, but because of its larger size, it is not deformed. The two arbaciid sea urchins in that region, Tetrapygus niger and Arbacia stellata, are not infested by it; their four anal plates may prevent the crab of entering the intestine.

B

Fig. 4.197: Caenocentrotus gibbosus. (A) Aboral side with remaining spines, diameter of test 32 mm; Peru; ZMH. (B) Close-up of the apical disc. The claw of the parasitic crab protrudes from the anal opening.



Genus Colobocentrotus Brandt, 1835 Colobocentrotus and the subgenus C. (Podophora) are probably the most specialized of all regular sea urchins. They live in an extreme habitat, the surf zone of rocky coastlines, where they are exposed to the full force of breaking waves and powerful surge. They have evolved numerous, large, muscular, oral tube feet with strong, suckered discs, with which they cling tenaciously to the rocky substrate. Their aboral spines form a more or less close-fitting pavement that hardly offers resistance to the rolling waves. Test: Strong; hemispherical with a more or less sharp edge; elongated in outline along the axis passing through genital plate 4 and ocular plate II; oral side flattened or slightly concave. Apical system: Dicyclic; all plates densely tuberculated. Ambulacra: Each plate with 6–12 pore pairs, widening to broad phyllodes on the oral side. Interambulacra: Secondary tubercles scarcely smaller than primaries; all tubercles very massive. Peristome: Large and elongated, buccal notches shallow, but with distinct tags. Spines: On the aboral side, short and peg-like; around the more or less sharp ambitus, as downward-directed fringe of flattened paddle-like spines. The genus consists of two subgenera: Colobocentrotus (Colobocentrotus) Brandt, 1835. Monospecific, Bonin Island, Japan and Guam. Colobocentrotus (Podophora) L. Agassiz, 1840. Two species. Indo-Central Pacific. Colobocentrotus (Colobocentrotus) has knob-like spines and multiple larger tubercles on ambulacral and interambulacral plates. In contrast, C. (Podophora) carries only one large tubercle per ambulacral plate and short truncated spines forming a dense tesselation. Subgenus Colobocentrotus (Colobocentrotus) Brandt, 1835 Colobocentrotus (Colobocentrotus) mertensii Brandt, 1835 (Fig. 4.198) Test: Slightly transverse elongated, regularly hemispherical; oral side slightly concave; width up to 70 mm. Apical system: All plates thickened, so that the periproct and the gonopores are depressed. Ambulacra: 6–7 pairs per arc, near the peristomial edge in double oblique series extending over the whole plate; multiple tubercles on each high plate; adapically tuberculated part of plates thickened, pores sunken; all plates densely set with miliary tubercles. Interambulacra: Narrower than ambulacra at the peristomial edge; two horizontal series of larger tubercles on each plate; largest around the ambitus; adapical plates

4.2.9 Order Camarodonta Jackson, 1912 

 295

thickened with depressed sutures; all plates densely set with miliary tubercles. Peristome: Naked with small platelets, buccal plates small; notches very shallow, but with long tags. Spines: Around the ambitus rectangular like a fringe, aboral spines short, ending in a knob, few oral spines short and slender. Color: The spines are aborally bluish green, orally lighter green with a purplish edge; the cleaned test is white to green with purplish tubercles and/or a purplish tinge, on the oral side wholly white. Distribution: This species is known only from the Bonin Islands and Guam in the West Pacific living in shallow water. Subgenus Colobocentrotus (Podophora) L. Agassiz, 1840 The subgenus contains two very similar species. Colobocentrotus (Podophora) atratus Linné, 1758 (Fig. 4.199) Test: Very solid, aboral side convex, oral side concave; maximum width 65 mm. Apical system: All plates, except the madreporite, covered with tubercles as large as on the adapical interambulacra; gonopores at the outer edge of plates. Ambulacra: 8–12 pore pairs on each plate in steep double arcs, pore zones on the oral side very much widened with densely crowded pore pairs; primary tubercles in two regular series, on the oral side much reduced in size; very small miliary tubercles between the rows, no secondaries. Interambulacra: On the aboral side. large tubercles in regular vertical series, secondaries almost as large as primaries, around the ambitus primary tubercles become dominant, decreasing in size on the oral side; plates very narrow at the peristomial edge. Peristome: Large and elongated; buccal notches small and shallow; peristomial membrane almost naked. Spines: On the aboral side, very short and with broadly truncated, angular tips, forming a tessellated pavement; at the ambitus, arranged as a ring of longer paddle-like spines, rounded at the end and directed downward; on the oral side, they are small and flattened. Color: The tesselated spines are dark purple to almost black. On the oral side, they are lighter while the tube feet are red brown. The denuded test is violet on the upper side and dirty whitish at the ambitus and on the oral side. Distribution: This species lives from East Africa to the Malayan Archipelago and as far as Hawaii. It has not been reported from Australia or the Pacific Islands. It is restricted to the littoral zone.

296 

 4.2 Subclass Euechinoidea Bronn, 1860

B

A

C

D

E

Fig. 4.198: Colobocentrotus (C.) mertensii. (A) Aboral side of test, longest diameter 41 mm; Bonin Island, Japan, West Pacific. ZMUC. (B) Side view: the largest tubercles occur around the sharp ambitus. (C) Side view, largest diameter with spines 66 mm; Guam. The spines are knob-shaped forming a convex surface aborally with longer fringe-like spines around the ambitus (sketch after a photo of H. van Noordenburg). (D) Ambulacral plates on the upper side. The pore pairs are arranged in a dense arc of 7–8; there are three larger tubercles per plate, set with knob-like spines. (E) Ambulacral plates at the peristomial edge: the pore pairs, pierced by suckered podia, are spread over the whole plate. Scale: 4 mm (Mortensen 1943).

Colobocentrotus (Podophora) pedifer Blainville, 1825 (Fig. 4.200) This species is very similar to C. (Podophora) atratus. It differs in the shape of the ambital spines: in C. (P). pedifer, the spines are angular forming generally an unbroken ring, in C. (P). atratus, they are rounded at the ends. The color of C. (P). pedifer is greenish or olive. It is restricted to the Tuamotu Islands and Hawaii. Genus Echinometra Gray, 1825 The genus is characterized by an elongated test, the longitudinal axis leading through ocular plate A I and genital plate IA 3. The ambulacra are polyporous, with 4 to 10 pore pairs to each arc. The species of Echinometra belongs to the most common shallow water echinoids living in tropical and subtropical regions around the world.

Test: Rather solid; aboral side high convex to flat, oral side concave; size moderate to large. Apical system: Transversely oval; madreporite slightly enlarged; plates with a varying number of tubercles, ocular plates all exsert or one or two insert; suranal plate indistinct. Ambulacra: One large primary tubercle on each plate, much smaller secondaries forming fairly regular series in pore zones, very small miliaries alternating along the median line; 4–10 pore pairs to each arc; pore zones on the oral side slightly widened with more densely set rows of pore pairs. Interambulacra: Two regular series of large primary tubercles, smaller secondaries in more or less regular, vertical rows, at the ambitus almost of same size as primaries; tiny miliaries around the large areoles.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

C

D

E

F

 297

Fig. 4.199: Colobocentrotus (Podophora) atratus. (A) Ambulacral plates on the upper side: per plate there are 8 to 12 pore pairs arranged in double arcs. (B) Ambulacral plates at the peristomial edge: the strongly widened pore zones are set with very numerous pore pairs associated to tube feet with sucking discs. Scale: 2 mm. Mortensen. (C) Aboral side of test, longest diameter 40 mm; Ile de la Réunion, Indian Ocean. (D) Oral side. (E) Aboral side of test with spines, longest diameter of test 36 mm, height with spines 19 mm; Ile de la Réunion, Indian Ocean. On the upper side, the spines are short and broadly truncated, forming a tesselated pavement. At the ambitus, they become flattened and longer with rounded ends forming a fringe. (F) Oral side: the underside is covered by numerous podia with strong, suckered discs, the flattened spines are small and inconspicuous.

A

B

Fig. 4.200: Colobocentrotus (Podophora) pedifer. (A) Aboral side of test, longest diameter 62 mm; Hawaii. The tubercles are large and of subequal size, even on the apical plates. (B) Side view, width with spines 65 mm; Hawaii. The flat ambital spines are more or less sharply truncated. The aboral spines form a closed pavement (sketches after photos of H. van Noordenburg).

298 

 4.2 Subclass Euechinoidea Bronn, 1860

Peristome: Large and elongated; buccal membrane almost naked or with only a few plates; notches distinct. Spines: Primaries moderately long, usually strong and tapering to a pointed tip, sometimes thickened or clavate, also the secondary spines may be clavate; circum-oral spines flattened, but not widened; few, tiny, and pointed miliary spines. The genus consists of six species: Echinometra insularis H. L. Clark, 1912. Endemic to the Easter Island and Galapagos Islands. Echinometra lucunter Linné, 1758. Caribbean and Atlantic to West Africa; 1 to 45 m. Echinometra mathaei Blainville, 1825. Widespread from the Red Sea to South Africa, from Japan to Australia and from Hawaii to the Central Pacific islands; littoral to 30 m. Echinometra oblonga Blainville, 1825. Indian Ocean to the East Pacific. Echinometra vanbrunti A. Agassiz, 1863. West coast of America; 1 to 50 m. Echinometra viridis A. Agassiz, 1863. West Indies; 1 to 40 m. Biology: The species of Echinometra may be very common on hard substrates. They prefer exposed habitats in the shallow fore reef, often in the surf zone, where they are found in large numbers. The animals live in shallow excavations in the reef rock, being abraded by means of their spines and teeth. They may even fall dry at low tide, crouching in the little remaining water. They feed mostly at night, remaining in their holes, at most clearing the near vicinity of all suitable organisms. Usually, they return to their own burrows. Echinometra lucunter has been observed having ward off intruders of the same species when they try to occupy another burrow. The resident urchin defends its crevice by biting and pushing, generally successfully (Hendler et al. 1995). Literature: Fell 1974; Serafy 1979; Hendler et  al. 1995; Arakaki & Uehara 1999; Landry et al. 2003. Echinometra insularis H. L. Clark, 1912 (Fig. 4.201 A) Test: Well elevated, in adults more than in younger specimens. Apical system: All ocular plates exsert. Ambulacra: Usually with 5 pore pairs to each plate at the ambitus, toward the apical disc often becoming six; on the oral side irregular and difficult to recognize; pore zones conspicuously widened. Color: Purplish. Distribution: This species is endemic to the Easter Island off Chile and live in very shallow water. Remark: Echinometra mathaei differs from E. insularis by the arrangement of the oral pore pairs having the subam-

bital pore pairs regular and distinct and the pore zones barely widened. Echinometra vanbrunti is distinguished by its low test and by having 6 to 8 pore pairs per arc on the aboral side. Echinometra lucunter Linné, 1758 (Fig. 4.201 B–D) Test: Elongated; often rounded pentagonal; maximum length more than 100 mm. Apical system: Only ocular plate V insert, others usually exsert, madreporite enlarged, all plates densely tuberculated. Ambulacra: Broad, pore pairs in arcs of 6 to 8; uppermost pair and tube foot enlarged; pore zones widened on the oral side; two series of large primary tubercles, smaller than interambulacral ones, small secondaries alternating along the median line and more or less irregular in the pore zones; numerous tiny miliary tubercles. Interambulacra: One large primary tubercle with large areole on each plate forming two regular series, much smaller secondaries in fairly regular series on both sides, remainder of plates densely covered by miliary tubercles. Peristome: Very large, buccal notches distinct; peristomial membrane with scattered platelets; enormous tags on top of the auricles. Spines: Usually slender, length about the test diameter, sometimes shorter and stouter, orally flattened; secondaries distinctly smaller, many very small miliaries. Color: The spines are very dark olive, greenish violet to purple toward the tips, the milled ring near the base dark. Usually the urchins look black, sometimes reddish. In life, the test is light brown to dark red brown aborally, at the oral side creamy brown. The cleaned test is whitish with light green or light purple tubercles. The range of variety is large. Distribution: This species is known from North Carolina, USA, and the Bermudas, throughout the Caribbean and eastern Central America southward to Brazil, also in West Africa. A subspecies is found off Ascension and St. Helena Islands. Echinometra lucunter lives from the littoral to a depth of 45 m. Echinometra mathaei Blainville, 1825 (Fig. 4.202) Test: Shape variable from strongly elongated to, rarely, almost circular; aboral side more or less high convex, apex often flattened, oral side concave; length can reach about 90 mm. Apical system: Madreporite slightly enlarged; plates with a varying number of tubercles, ocular plates all exsert. Ambulacra: Pore pairs in arcs of 4 and 5, the uppermost pair of each arc slightly enlarged (the tube foot is

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 299

B

D

Fig. 4.201: (A) Echinometra insularis. Aboral side, length with spines 103 mm; Easter Island, Southeast Pacific. ZMUC. The spines are slender and uniformly purple. (B–D) Echinometra lucunter. (B) Aboral side, length with spines 80 mm; west coast of Florida, USA. The interambulacral primary spines are slender and distinctly longer than those in the ambulacra. (C) Aboral side of test, length 59 mm; Florida, USA. (D) Oral side: the pore zones are widened, but narrow again at the peristomial edge. The buccal notches are distinct.

also longer); one large primary tubercle on each plate, much smaller secondaries forming fairly regular series in pore zones, very small miliaries alternating along the median line. Interambulacra: Two regular series of large primary tubercles, not much larger than in ambulacra, smaller secondaries in more or less regular, vertical rows, at the

ambitus almost of same size as primaries; tiny miliaries around the large areoles. Peristome: Large and elongated; buccal membrane almost naked or with only a few plates; notches distinct. Spines: Primaries at the ambitus half the diameter of test, orally and aborally shorter; usually solid and tapering to the rather pointed tip, sometimes they may be shorter and

300 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

Fig. 4.202: (A–D) Echinometra mathaei. (A) Aboral side of test, length 37 mm; Réunion, Indian Ocean. The species is elongated along the axis ambulacrum A I and interambulacrum IA 3. On the oral side, the pore zones are not widened. Ambulacral and interambulacral tubercles are of subequal size. (B) Close-up of aboral side: the pore pairs are arranged in arcs of four. Scale: 10 mm. (C) Aboral side, length with spines 65 mm; Bismarck Archipelago, New Guinea. ZMH. The spination in the whole appears rather stout, the primary and secondary spines are of subequal size. The white milled rings at the base of the spines and the white tips are distinct. (D) Underwater, Bohol, Philippines. The echinoids live in coral reefs, often hiding in crevices (photo by H. Moosleitner).

thicker; circum-oral spines flattened, but not widened; few, tiny, pointed miliary spines. Color: The living animal is mostly dark brown, the spines lighter, often with white tip and white milled ring at the base. The color may vary from white to black, greenish, or pinkish. The cleaned test is whitish green or with a faint pinkish tint. Biology: Echinometra mathaei is known to live in holes and tunnels among coral blocks in reefs. These urchins feed on plants and encrusting organisms, especially sponges.

Distribution: This species is one of the most common sea urchins in the Indo-West Pacific. It is known from the Gulf of Suez to Durban on the east coast of Africa, from Japan to Australia (except the southern coast), and from Hawaii to the Pacific islands. Echinometra mathaei is restricted to the littoral zone and down to 30 m. Remarks: Echinometra mathaei is easily recognizable from the many other co-occurring regular sea urchins of the region by its elongated test and the stout spines. The similarly elongated Parasalenia differs from E. mathaei

4.2.9 Order Camarodonta Jackson, 1912 



A

 301

B

C

Fig. 4.203: Echinometra oblonga. (A) Side view of test, length 37 mm; Vanuatu. ZMUC. The primary tubercles of the aboral side are larger than those at the ambitus or adorally. (B) Side view with spines, length 42 mm; Vanuatu. ZMUC. The upper spines are erect. (C) Side view, length with spines 41 mm; Gilbert Islands, Central Pacific.

by having a much larger apical system with characteristically pointed genital plates and more distinct white rings around the spines. Echinometra oblonga Blainville, 1825 (Fig. 4.203) This species is characterized by upright directed aboral primary spines, more or less thickened. The range of variation in shape and color is extremely large. The species is very closely related to Echinometra mathaei. Test: More or less highly domed with concave oral side. Ambulacra: 4 to 5 pore pairs per arc. Interambulacra: Tubercles on the upper side enlarged when carrying thickened spines. Primary spines: Usually thickened but may also be slender tapering to a rather pointed tip. Color: The living animal is mostly dark brown, the spines are typically a uniform black, brown, or green without white tip in contrast to Echinometra. mathaei. The spines may also be a uniform white or lavender. Biology: The position of the spines indicates that this species is a rock borer or lives in holes and tunnels among coral blocks in reefs. These urchins feed encrusting organisms, sponges, and plants. Distribution: Reported from East Africa, Mauritius, and the Maldives through the Philippines, Indonesia, and Papua New Guinea to Okinawa, Guam, and Hawaii, from the South Pacific islands to Clarion and Socorro Island off Mexico, Cocos Island off Costa Rica and Galapagos Islands. This species is a strictly littoral form.

Remarks: Echinometra oblonga is not at all easily recognizable. The black upright directed and thickened spines are typical, but by no means a constant feature. The variation in color and shape of the spines is very large. Mortensen (1943) admits that there are “no reliable characters in the test distinguishing oblonga from the typical mathaei.” Only by molecular-genetic examinations, it is possible to separate these species clearly. Landry et  al. (2003) revealed that E. oblonga differentiates into a western and central Pacific clade in a beginning speciation process. Echinometra vanbrunti A. Agassiz, 1863 (Fig. 4.203 A, B) Test: Variable from elongated to almost round, height from low hemispherical to highly domed; oral side more or less flattened, in the whole concave; maximum length of test 80 mm. Apical system: Usually ocular plates I and V insert; plates covered with tubercles of various size. Ambulacra: Number of pore pairs per arc usually 7 to 8, not rarely 5 or 6; pore zones sometimes widened on oral side; two series of primary tubercles, vertical row of secondaries in pore zone. Interambulacra: Two series of primary tubercles, flanked on either side by secondaries. Peristome: Few plates scattered on peristomial membrane; notches usually without conspicuous “tags”. Spines: Moderately stout or slender, tapering to a rather sharp point; as long as diameter of test, but may be shorter; milled ring inconspicuous.

302 

 4.2 Subclass Euechinoidea Bronn, 1860

Color: The spines are uniformly dark purple or dark green appearing black, the bare test is light purplish, especially aborally, with darker tubercles. Distribution: This species is known from the western coast of America from central California to Peru from the littoral zone to a depth of 50 m. Biology: Echinometra vanbrunti lives on rocky bottoms mostly in the surf zone, withdrawn in crevices, presumably similar to E. lucunter. Echinometra viridis A. Agassiz, 1863 (Fig. 4.204 C, D) Test: Elongated, although more often nearly circular than in E. lucunter; moderately domed, uppermost side flattened, oral side slightly concave; maximum length 100 mm, mostly less. Apical system: Rather naked, all ocular plates exsert. Ambulacra: With 5 to 6 pore pairs in one arc, uppermost pair enlarged with a longer tube foot; pore zones not widened, the arcs remain erect; one large tubercle per plate in regular series, secondaries distinctly smaller, few tiny militaries. Interambulacra: Two series of regular, large primary tubercles, smaller secondaries; tiny, scattered miliaries. Spines: Relatively long, strong, and sharply pointed. Color: The living specimens are in general reddish brown, as are the basal muscles of the spines. In contrast the milled ring is conspicuously white. The spines are a brownish green, distally olive green, but tipped with purple. The oral side is lighter. The cleaned test is creamy white. Biology: Echinometra viridis is not a rock borer, but it usually remains hidden under reef blocks or in crevices. These urchins prefer protected habitats. They may be found aggregated among mangrove roots or on branching corals like Acropora in sheltered waters grazing on algae (Hendler et al. 1995). Distribution: This species is restricted to the Caribbean region from southern Florida to Venezuela living in the littoral zone and down to a depth of 40 m. Genus Echinostrephus A. Agassiz, 1863 This genus containing two species is characterized by having an extraordinarily high ambitus. This feature is an adaptation to its mode of life. Test: Circular with flattened aboral and oral side; ambitus above mid-height; small forms. Apical system: Dicyclic; plates only set with small granules; periproct small. Ambulacra: 3–4 pore pairs in short rows, uppermost pair usually larger than the two others; pore zones slightly widened at peristomial edge; primary tubercles large.

Interambulacra: Each plate with a row of subequal tubercles. Peristome: Much larger than apical disc; buccal notches shallow. Spines: On the aboral side, long and slender; at the sides and orally, short. The genus contains of two very similar species: Echinostrephus aciculatus A. Agassiz, 1863 Echinostrephus molaris Blainville, 1825 They differ in the number of pore pairs, Echinostrephus molaris having 3 per arc and E. aciculatus 4. The former has virtually naked apical plates; in E. aciculatus, they are tuberculated and bear several spines. Both species have the same lifestyle. Biology: Echinostrephus is a very specialized sea urchin, one of the very rare filter feeders in echinoids. The animal bores vertical cylindrical funnels of more than 100  mm depth into the soft coral rock, obviously with the short spines of the sides. The urchin sits at the top of its hole, but when it is disturbed it will drop to the bottom, raising its long spines. It is impossible to get it out of the hole. The echinoid feeds on organic material washed into the hollow and what it can reach with the aboral tube feet in the close vicinity. Adapted to this behavior, one of the tube feet in each arc is longer than the others. Literature: Rowe & Gates 1995; Miskelly 2002. Echinostrephus aciculatus A. Agassiz, 1863 (Fig. 4.205 E) This species is almost identical to Echinostrephus molaris in shape and lifestyle. It differs mainly in the number of pore pairs per plate having 4 rather than 3. Distribution: Found in the west Central Pacific from Japan to Lord Howe Island and from Hawaii to the South Sea. It is likely that the species has also reached Baja California, Mexico. (H. van Noordenburg, personal communication. Echinostrephus molaris Blainville, 1825 (Fig. 4.205 A–D, 4.206) Test: In outline round or pentagonal, upper side broader than oral side and flattened; maximum diameter 23 mm. Apical system: Plates naked, periproctal opening with small anal tube. Ambulacra: Narrow, 3 pore pairs arranged in oblique rows from the apical disc to the peristome, on the aboral side the uppermost is larger than the two other pore pairs; two regular series of large primary tubercles, small secondaries alternating along the median line and rather irregularly distributed in the pore zones. Interambulacra: Two series of primary tubercles, flanked on both sides by secondaries of about same size, forming

4.2.9 Order Camarodonta Jackson, 1912 



A

B

C

D

 303

Fig. 4.204: (A, B) Echinometra vanbrunti. (A) Aboral side of test, length 38 mm; Nicoya Peninsula, Costa Rica. The upper side is quite flat and only slightly elongated. (B) Oral side, length with spines 56 mm; Nicoya Peninsula, Costa Rica. The slender primary spines are dark purplish and much longer than the secondaries. (C, D) Echinometra viridis. Aboral side of test, length 30 mm; Cartagena, Columbia. The test is subcircular. (D) Oral side, length with spines 59 mm; Cartagena, Columbia.

304 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

E

Fig. 4.205: (A–D) Echinostrephus molaris. Aboral side of test, diameter 17 mm, height 8.5 mm; Ile de la Réunion, Indian Ocean. (B) Oral side. (C) Side view. The primary tubercles are of approximately similar size from the apical disc to the very large peristome. The ambitus is very high, giving the test the typical vase-shaped form. (D) Apical system: the plates are naked, and in the center an anal tube is developed. Scale: 1 mm (Mortensen 1943). (E) Echinostrephus aciculatus. Side view, diameter with spines 31 mm. Baja California, Mexico. The upper spines are much longer than the oral ones and those at the sides (sketch after a photo of H. van Noordenburg).

dense horizontal rows of 3 to 4 tubercles; tiny scattered militaries. Peristome: Buccal membrane rather delicate, several plates, no “lip” around the mouth; notches small. Spines: Longest on the flattened aboral side, but not reaching the diameter of test; short around the sides and slightly curved on the oral side; distally pointed. Color: The spines are dark or lighter purplish on the upper side, whitish on the oral side. The cleaned test is dull green, sometimes with a purplish tinge, and whitish around the peristome. The apical plates may be darker. Distribution: This species is widely known in the Indo-Pacific from the Red Sea and the east coast of Africa southward to Durban, from the Bonin Islands to Australia and the Fiji Islands. It lives in the littoral zone down to about 50 m.

Fig. 4.206: Echinostrephus molaris, Sri Lanka. Three specimens sit on the top of their hollows. When the echinoid is disturbed, it drops down into the hole with the upper spines erect (photo by H. Moosleitner).

4.2.9 Order Camarodonta Jackson, 1912 



A

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 305

Fig. 4.207: Evechinus chloroticus. (A) Aboral side of test, diameter 86 mm; New Zealand, North Island. The pore zones in the ambulacra form a broad band from the apical disc to the peristome. (B) Aboral side, diameter with spines 68 mm; New Zealand. MfN. The spines are slender, the primaries much longer than the secondaries. (C) Apical system: the outer edges of the ocular plates are pointed. (D) Plates of half an ambulacrum: the plates are very low, each with 3 pore pairs. The large primary tubercles are developed only on every second or third plate; the plates without a tubercle are much smaller or even occluded. The pore pairs form three irregular, vertical series. Scale: 2 mm (Mortensen 1943).

Genus Evechinus Verrill, 1871 The monospecific genus is characterized by widely spaced columns of pore pairs. Evechinus chloroticus Valenciennes, 1836 (Fig. 4.207) Test: In outline circular; in profile low hemispherical; peristome distinctly sunken; diameter of test may reach more than 140 mm. Apical system: Rather small, usually one large tubercle on every genital and ocular plate beside several smaller

ones; madreporite enlarged; hemicyclic with ocular plates I and V broadly insert; edges of ocular plates pointed at the distal end; outer periproctal plates tuberculated. Ambulacra: Trigeminate with pore pairs densely arranged in three vertical series, the outer and inner ones fairly regular, the middle more irregular, forming a broad band of about same width, only slightly restricted at the peristomial edge; primary tubercles on the oral side on every second plate, at the ambitus and the upper side on every third one (difficult to recognize, because the plates

306 

 4.2 Subclass Euechinoidea Bronn, 1860

without primary tubercles are much compressed or even occluded from the midline of the area), near the apical system, the primaries may be rather irregular or even rudimentary; secondary tubercles of the median zone and in the pore zones much smaller. Interambulacra: Narrower than ambulacra at the peristomial edge; two series of primary tubercles with flanking slightly smaller secondaries forming fairly regular series in the median zone, but more irregularly arranged on the outer side of the plates; remaining space densely covered by small miliary tubercles. Peristome: Small, buccal plates forming a ring around the mouth, not paired; membrane with small, scattered plates; notches distinct. Spines: Coarse, simply tapering to a blunt distal end, usually not exceeding 15 mm. Color: The test is brightly green with conspicuously white tubercles, lighter on the oral side. The spines are also greenish, often with white tips. Biology: Evechinus chloroticus is found in rock pools and coarse shallow-water sediments. In sheltered water, it occurs also on fine sandy or mud substrate. Specimens that live in more exposed habitats have generally shorter spines and the secondaries are of subequal size for better protection. Distribution: This species is restricted to New Zealand waters including the Chatham and the Kermadec Islands. It lives from the littoral down to a depth of 20 m. Remarks: Evechinus chloroticus differs from (green specimens of) Heliocidaris erythrogramma by the arrangement of the pore pairs; in the former, they are developed in three more or less regular vertical series, in the latter in distinct arcs of 7–9 pore pairs. Evechinus chloroticus is distinguished from the rather similar Selenechinus by lacking phyllodes. Literature: McKnight 1969. Genus Heliocidaris L. Agassiz & Desor, 1846 Recently (Mooi & Kroh 2010), the genera Anthocidaris Lütken, 1864, Pachechinus A. Agassiz, 1872, and Pachycentrotus H. L. Clark 1912, were synonymized with Heliocidaris. Test: In outline round, in profile more or less domed. Apical system: Hemicyclic; madreporite enlarged. Ambulacra: Polyporous, pore pairs in arcs or two vertical series; one primary tubercle per plate; on oral side distinct phyllodes. Interambulacra: A primary tubercle flanked by large secondaries. Spines: More or less solid, in length about half the test diameter. Six species are included in this genus: Heliocidaris australiae A. Agassiz, 1872. Likely to be lecithotrophic; southern Australia.

Heliocidaris bajulus Dartnall, 1972. Brood-protecting; Tasmania. Heliocidaris crassispina A. Agassiz, 1864. Planktotrophic; Japan and South China Sea. Heliocidaris erythrogramma Valenciennes, 1846. Lecithotrophic; southern Australia. Heliocidaris robertsi Lindley, 2004. Development unknown; Papua New Guinea. Heliocidaris tuberculata Lamarck, 1816. Planktotrophic; east coast of Australia, Kermadec Islands, North New Zealand. Literature: Baker 1982; Rowe & Gates 1995; Williams & Anderson 1995; Miskelly 2002; Hart et al. 2011. Heliocidaris australiae A. Agassiz, 1872 (synonym Pachechinus australiae) (Fig. 4.208) Test: Round; strong; upper side more or less domed, sometimes subglobular or subconical; oral side flattened; maximum diameter 40 mm. Apical system: Ocular plates I and V broadly insert; all plates with numerous tubercles, except the periproctal ones. Ambulacra: 4 pore pairs per arc, three outer ones separated by small tubercles from the inner pore pair; two series of large primary tubercles, surrounded by numerous smaller ones of various size. Interambulacra: Two series of primary tubercles in the center of the plates, secondaries and smaller ones on either side, often forming oblique rows with the ambulacral tubercles. All tubercles remain equal-sized from the apex to the peristome. Peristome: Plates of buccal membrane naked, notches small and sharp, edge thickened. Spines: Primaries short and uniform, not exceeding 5 mm; secondaries slightly club-shaped. Color: The spines may be dull green, white-tipped or more or less banded or bright violet and white-tipped and banded as well. The bare test is grayish or greenish with purplish shades, the oral side whitish. In both forms, the tubercles are light, as are the plates at the buccal membrane. Distribution: This species is found in the southern part of Australia and Tasmania. It lives mainly in shallow water, but is also recorded at a depth of 70 m. Biology: Hart et al. (2011) suspected this species to be lecithotrophic like H. erythrogramma. Remarks: Heliocidaris australiae is distinguished from the other species of Heliocidaris by its shorter, uniform spines and by having 4 pore pairs to a plate, H. erythrogramma has 7–8 and H. tuberculata 9–10 pore pairs per arc.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 307

B

D

Fig. 4.208: Heliocidaris australiae. (A) Aboral side of test, southern Australia. The numerous spines are short, stout, and faintly banded. The buccal membrane is densely packed with plates (photo by A. Miskelly). (B) Side view of test, diameter 32 mm; South Australia. (C) Oral side: the test is densely set with tubercles of different size, which remain approximately equal from the apical system to the peristome. (D) Ambulacral plates: the arrangement of the pore pairs is characteristic, a single inner pore pair separated from the three outer ones by several small tubercles. Scale: 2 mm (Mortensen 1943).

Heliocidaris bajulus Dartnall, 1972 (synonyms Pachycentrotus bajulus and Pachechinus bajulus) (Fig. 4.209 A, B) Test: Slightly pentagonal, holotype 33 mm in diameter. Apical system: Ocular plates I, IV, and V broadly insert, only O II and III exsert; each genital and ocular plate carries a large tubercle; madreporite inflated; genital pores in females larger than in males; periproct with imbricating small plates, anal opening eccentric. Ambulacra: Each plate with a large primary tubercle, two further smaller tubercles near the midline and adradially; 4 pore pairs per plate, the lowermost near the primary tubercle forming one series, the three other pore pairs arranged in a second series along the adradial edge.

Interambulacra: Set with one large primary tubercle per plate and heterogeneous smaller ones. Peristome: Buccal notches small and shallow. Primary spines: About 6  mm long, tapering to the tip, some spines are slightly expanded at the end. Secondary spines about 2 mm long. Color: The test is gray white, interambulacra and interporiferous zone of ambulacra are pale green, most intense around the apical system, gradually fading out toward the oral side. The madreporite has a buff color. The primary spines are banded in dull violet brown and green, the tips being white. Distribution: The species is endemic to Tasmania living in shallow water.

308 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

D

C

E

Fig. 4.209: (A, B) Heliocidaris bajulus. (A) Ambulacral plates. (B) Apical system. No scale (modified after Dartnall 1972). (C–E) Heliocidaris crassispina. (C) Aboral side of test, diameter 34 mm; Shizuoka, central Japan, Pacific. The primary tubercles are large, decreasing in size just below the ambitus. (D) Oral side: in the ambulacra, the pore pairs are arranged in dense oblique series forming phyllodes. The tubercles becoming small. (E) Aboral side with spines, diameter of test 45 mm, longest spine 36 mm; Shizuoka, central Japan, Pacific. Around one side of the test the spines are distinctly shorter than on the other side. The animal sits in its crevice with the short spines to the wall, the long ones directed to the open.

Biology: Heliocidaris bajulus is the only non-cidarid regular echinoid from Australia, which brood-protects its young. There is no marsupium, but the gonopores of the females are enlarged. The juveniles measure between 1 and 5.5 mm. The holotype carried 12 young, a paratype 17 scattered juveniles among the spines over the entire test. The embryos are enveloped in a thick gelatinous coat, which adheres to the pedicellariae of the female parent. Abbreviated development and metamorphosis like in H. erythrogramma occur within the jelly coat before the young hatch (Hart et al. 2011).

Heliocidaris crassispina A. Agassiz, 1864 (synonym Anthocidaris crassispina) (Fig. 4.209 C–E) Test: Round; rather low, regularly arched or more or less flattened at the apex; oral side broadly flattened, scarcely sunken toward the peristome; maximum diameter 63 mm. Apical system: Ocular plates I and V broadly insert; genital and ocular plates each with one large tubercle and few smaller ones; periproctal membrane not totally covered by plates, with stem-like structures around anus.



Ambulacra: Width more than three fourths of interambulacra at ambitus and much broader at the peristomial edge; pore zones widened on the oral side; pore pairs usually in arcs of 8, occasionally 7 or 9, each arc irregularly but distinctly curved; primary tubercles large, reaching about half the size or more of interambulacral primaries; secondaries in zigzag lines along the median sutures, and on the outer side, numerous smaller tubercles forming more or less regular vertical series in the pore zones; primary tubercles on the oral side much smaller. Interambulacra: Narrower than ambulacra at the peristomial edge; two series of large primary tubercles, secondaries in zigzag lines along the median zone, more or less irregular on the outer side of plates; all tubercles much smaller on the oral side. Peristome: Rather small; buccal plates naked; membrane scattered with a small number of platelets; buccal notches small, but distinct. Spines: On the aboral side, about as long as the diameter of test; on the oral side, much shorter; usually they are longer on one side; slender, tapering to a sharp point. Color: The spines are uniformly dark purplish, the bare test is grayish with dull greenish or slightly purplish tinge, the oral side and especially the pore zones distinctly lighter. Biology: Heliocidaris crassispina lives on hard substrates in shallow water with heavy wave motion, often in pits. The animals occupying such crevices remain there almost constantly by day and night. In these hollows, they sit directing the short spines to the wall behind them, the long ones expanding to the open. Specimens not inhabiting pits prefer more sheltered places and they are much more mobile, walking around, mostly at night, grazing on incrusting organisms (Yusa & Yamamoto 1994). Distribution: This species is known from Japan, from northern Honshu to southern Kyushu, Taiwan, and the southeastern coast of China. It lives from the intertidal zone to a depth of about 70 m. Remarks: Heliocidaris crassispina appears very similar to Mesocentrotus nudus, and their distributional ranges overlap from Sagami Bay to northern Honshu. Spined specimens often cannot be distinguished, except that the spines in Mesocentrotus nudus are generally shorter, but in H. crassispina, they may often be abraded. The test differs in the number of pore pairs per arc, usually 6 in M. nudus, 7–9 in H. crassispina. In the latter, the widened pore zones on the oral side are more conspicuous. Literature: Shigei 1986; Yusa & Yamamoto 1994.

4.2.9 Order Camarodonta Jackson, 1912 

 309

Heliocidaris erythrogramma Valenciennes, 1846 (Fig. 4.210) Test: Round; hemispherical or more or less flattened on the upper side; peristome sunken; diameter of test up to 85 mm. Apical system: With ocular plates I and V insert; madreporite enlarged; all plates tuberculated, also the outer periproctal ones; female with larger gonopores than males. Ambulacra: Pore pairs on the aboral side in distinct arcs of 7–8, on the oral side in dense and oblique rows of 3–5, no widened phyllodes; two series of primary tubercles, smaller than interambulacral ones, decreasing in size on the oral side; secondaries irregularly distributed and much smaller than primaries, adorally inconspicuous. Interambulacra: Two series of large tubercles, decreasing in size on the oral side; secondaries forming regular vertical rows in the median space, less regular on the outer side, smaller than primaries, but distinctly larger than the numerous other tubercles covering the remainder of the plates, adorally inconspicuous. Peristome: Membrane rather bare with a few small scattered plates; notches distinct. Spines: Primary spines hardly more than 25 mm long, mostly shorter; usually slender, tapering to a blunt tip, sometimes the aboral spines may be conspicuously thicker or even slightly spindle-shaped (var. armigera, Fig. 4.210 E); secondaries small; on the oral side, all spines are much smaller. Color: The spines are usually brownish olive, sometimes with white, they may also be greenish or purplish. The cleaned test is mostly uniformly green, it may sometimes be purplish, whitish, or greenish with a purplish tint. Distribution: Heliocidaris erythrogramma is restricted to the south of Australia from Shark Bay on the west coast to Port Stephens in New South Wales on the eastern coast. The species is also known in Tasmania. It lives exclusively in the littoral zone and down to a depth of 35 m. Biology: Heliocidaris erythrogramma is the most common sea urchin in Australia and occurs in the most diverse environments. Usually, this species is known to settle under less rough conditions than the better adopted Heliocidaris tuberculata being found under large stones below the tide zone, in sea grass beds in bays, in boat wrecks, and even on shell rubble. But it is also able to live in cracks and crevices on rock shelves in the intertidal zone, where the surf waves rush in and out, excavating shallow grooves to withstand the heavy currents. In this extreme habitat, H. erythrogramma has developed a dense canopy of short, stout spines to minimize the water resistance and to protect the test. The length of the oral spines may correspond with the form of the hollow.

310 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

E

Fig. 4.210: (A–D) Heliocidaris erythrogramma. Aboral side of test, diameter 64 mm; Tasmania, Australia. In the ambulacrum there are 6–8 pore pairs per plate forming conspicuously curved arcs. Scale: 10 mm. (B) Oral side of test: the pore zones are densely set with oblique rows of pore pairs, but they do not form phyllodes. (C) Aboral side with spines, diameter of test 78 mm; Victoria, Australia. The primary spines are slender; in the whole, the urchin looks rather sparsely spined. (D) Side view with spines, diameter 53 mm; Kalbarri, west coast of Australia. With its short spines the urchin “fits” into the shallow, hemispherical excavations, where it withstands the heavy surf. (E) Heliocidaris erythrogramma armigera (A. Agassiz, 1872). Aboral side with thick primary spines, diameter of test about 42 mm; Rottnest Island, Western Australia.



The development of the young is modified: the large, yolk-rich egg grows to an elongated, uniformly ciliated larva without arms. Metamorphosis is abbreviated, and the first podia and spines form on the embryo, while it drifts in the surface water without feeding. About 4 to 5 days after fertilization it sinks to the bottom. More tube feet, spines, and pedicellariae emerge, and after about 23  days, the juvenile begins to feed (Williams & Anderson 1975). Heliocidaris robertsi Lindley, 2004 Test: Low hemispherical oral side flattened, holotype with a diameter of 38 mm. Apical system: Small, only 18 % of test diameter; ocular plates I and V broadly insert; madreporite very large, the four other genital plates set with one large tubercle plus scattered much smaller ones. Ambulacra: 12 pore pairs in double series, broad pore zones at ambitus becoming much narrower adapically, widening with almost horizontal rows toward the peristome; a vertical row of secondaries separating the pore pairs; ambital primary tubercles only slightly smaller than those in interambulacra, flanked by a single prominent secondary tubercle, a few additional ones are smaller, militaries more or less along the median line. Interambulacra: Primary tubercles large; wide, tuberculated space between aureoles; around ambitus two distinct secondary tubercles, remainder of plates densely set with irregular miliaries; all tubercles decreasing in size toward the peristome, only primaries reach the edge. Peristome: Small, buccal notches shallow. Spines: Unknown. Color: Not reported. Occurrence: The holotype was found in the region around Cape Gazelle, New Britain, Papua New Guinea. Heliocidaris tuberculata Lamarck, 1816 (Fig. 4.211) This species is similar to Heliocidaris erythrogramma; it differs by the following features. Test: Stronger. Ambulacra: There are 8 to 10 pore pairs per arc. The pore zones on the oral side are distinctly widened to phyllodes. Tubercles: Larger and bear longer and usually thicker spines. The species has a planktotrophic larval development. The test may reach a maximum diameter of 115 mm. Distribution: The species is found along the central east and southeast coast of Australia, the Kermadec Islands, and northern New Zealand from the tidal zone to a depth of 54 m. Heliocidaris tuberculata is adapted to withstand extreme wave surge because of its solid test and its large

4.2.9 Order Camarodonta Jackson, 1912 

 311

number of tube feet with sucking discs to tightly grip the rocky bottom and by its thick spines. It often occurs with H. erythrogramma and Centrostephanus rodgersii, generally preferring environments with higher wave energy, in contrast to H. erythrogramma, which is dominant more distant from the surf. Genus Heterocentrotus Brandt, 1835 The genus is characterized by having very thick, pencillike spines, an adoption to its habitat in the surf zone. Test: Elongated with long axis through ocular plate II and genital plate 4. Apical system: Dicyclic with a small periproct. Ambulacra: 9 to 16 pore pairs per plate, arranged in a simple arc, a double arc, or in a broad band; on oral side broad phyllodes; single large primary tubercles. Interambulacra: Single large primary tubercles. Peristome: Elongated, buccal notches faint. Spines: Primaries very thick and dense, in diameter prismatic with three, four, or more flattened sides, secondaries short and truncated. The genus consists of two species: Heterocentrotus mamillatus Linné, 1758 Heterocentrotus trigonarius Lamarck, 1816 The two species differ in the following features: in Heterocentrotus mamillatus, the ambulacral tubercles of the upper side enlarge abruptly at the ambitus; in H. trigonarius, they gradually increase in size. The former has 9–12 pore pairs in one arc, the latter up to 16 pore pairs. Usually, in H. mamillatus, the spines are thicker and the tubercles larger than in H. trigonarius, but there is considerable variation. Biology: Both species live in shallow water in reefs. The echinoids wedge themselves tightly under coral blocks using its thick, long primary spines. They hide in daylight coming out at night to graze on encrusting organisms. Heterocentrotus mamillatus Linné, 1758 (Fig. 4.212) Test: Thick, oral side on the whole concave; width of test up to 80 mm. Apical system: Relatively small; ocular plates usually all exsert; all plates with large tubercles; periproctal plates naked. Ambulacra: Plates on the aboral side narrow and set with small tubercles, becoming abruptly much larger at the ambitus, almost as large as in interambulacra; smaller again near the peristome; pore zones with 9 to 16 pore pairs, rarely with 8 or up to 14; in long, steep arcs, on the oral side in oblique rows. Interambulacra: Very large primary tubercles on the aboral side, one per plate, much smaller on the oral side,

312 

A

C

 4.2 Subclass Euechinoidea Bronn, 1860

B

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Fig. 4.211: Heliocidaris tuberculata. (A) Aboral side of test, diameter 86 mm; New South Wales, Australia. (B) Oral side: the pore zones are distinctly widened. (C) Aboral side with spines, diameter of test 44 mm; Port Stephens, New South Wales, Australia. The primary spines are long and solid. (D) Oral side: the spines are much shorter and finer than on the upper side.

▸ Fig. 4.212: Heterocentrotus mamillatus. (A) Aboral side of test, width 49 mm; Negros, Philippines. The interambulacral plates are high,

each carrying a single large tubercle. (B) Oblique view: the primary spines in the aboral ambulacra are small, abruptly increasing in size at the ambitus (A = ambulacrum). (C) Aboral side with spines, width of test about 35 mm; Hawaii. The primary spines parallel to the long axis are longer than the other. They serve to wedge the animal between coral blocks in heavy waves. (D) Close-up of upper side: the secondary spines are very short and distally thickened and truncated. The uppermost ambulacral primary spines have the same shape, and the apical disc is also densely covered by these short spines. They serve to protect the test against heavy wave surge, offering little resistance to the water currents. (E) Side view with spines, width of test about 75 mm; Negros, Philippines. The upper spines are very thick and strong, the distal ends bluntly triangular and banded.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

E B

D growing interambulacran primary spine

ambulacrum

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 313

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E D

Fig. 4.213: Heterocentrotus trigonarius. (A) Ambulacral plates at the peristomial edge: the pore zones are strongly widened. Scale: 2 mm. (B) Ambulacral plates at the ambitus: the compound plate is composed of 16 parts, each perforated by a pore pair. In the upper plate, there is a tendency to develop a double arc, especially in large specimens. Scale: 3 mm (Mortensen 1943). (C) Aboral side of test, width 44 mm; La Réunion. Each plate is set with a large tubercle. The tubercles in the ambulacra increase gradually in size toward the ambitus. (D) Oblique view: the small uppermost tubercles in the ambulacra increase gradually in size toward the ambitus (A = ambulacrum). (E) Aboral side of a young specimen, width of test 23 mm; Réunion. The echinoid already shows differentiated spines.

secondaries very small and densely distributed over the remaining space. Peristome: Very large; numerous peristomial plates and buccal plates densely tuberculated and set with small flattened spines; notches shallow, but distinct. Spines: Primary spines of upper side and around the ambitus very long, reaching 100 mm, thickened at the end or more slender, distal ends triangularly blunt; strongly flattened on the oral side; secondaries very short and broadly truncated. Color: The primary spines may be light to dark brown or reddish brown, in the thick form with irregular lighter bands at the distal end, the short secondaries vary from purplish black to whitish. The denuded test is uniformly white. Distribution: Heterocentrotus mamillatus is found across the whole Indo-West Pacific, from the Red Sea and East

Africa over the Malayan Archipelago to Hawaii. It is not found around India. The species lives mainly in the littoral zone, but is also reported from a depth of 25 m. Heterocentrotus trigonarius Lamarck, 1816 (Fig. 4.213) Living in the same habitat, this species resembles very much to Heterocentrotus mamillatus. It differs in the following features. Test: May reach a maximum width of 100 mm. Ambulacra: Pore zones with usually 15–16 pore pairs per arc, varying from 14 up to 19, in large specimens adapically often in double arcs; strongly widened adorally with oblique series of pore pairs; primary tubercles increasing in size gradually from the apical disc to the ambitus.

4.2.9 Order Camarodonta Jackson, 1912 



A

 315

B

Fig. 4.214: Selenechinus armatus. (A) Aboral side, partly with spines; diameter 100 mm; Philippines. ZMUC. (B) Side view: the surface of the test is densely set with small granules.

Spines: Primary spines highly variable from thick and as long as the test diameter to more slender and reaching double the diameter. Color: The primary spines are more or less dark brown to greenish olive, sometimes banded distally. The secondaries are apparently never whitish; the cleaned test is whitish, often tinted purplish or greenish. Distribution: Heterocentrotus trigonarius is known from the eastern coast of Africa, except in the Red Sea, to the Marquesas Islands. It has not been recorded either in Hawaii or in Australia. This sea urchin is mainly a littoral species, but is found down to 35 m. Genus Selenechinus de Meijere, 1903 The monospecific genus is characterized by a large test the upper side being set with small but prominent primary tubercles and covered by numerous small granules. Selenechinus armatus de Meijere, 1902 (Fig. 4.214) Test: Circular in outline, regularly hemispherical, peristome conspicuously sunken; diameter up to 100 mm. Apical system: Hemicyclic with ocular plates I and V broadly insert; inner part of all plates densely tuberculated; periproctal plates small, anal opening subcentral. Ambulacra: Pore pairs in oblique series of three, forming a broad band, no phyllodes; broad granular interporiferous zone around ambitus; primary tubercles on every second or third compound plate; on aboral side much smaller than on oral side, where each plate is set. Interambulacra: Secondary tubercles on oral side almost as large as primaries with vertical and horizontal series admedially; on the upper side much smaller, in contrast to the primaries, which remain very conspicuous; no naked median space.

Peristome: Buccal plates distant from each other; shallow, but distinct buccal notches. Spines: Primary spines reach a length of about 30  mm, robust looking but brittle; secondary spines much smaller and finer, pointed. Color: The spines are grayish, the base with a reddish brown tint; the cleaned test is creamy white. Distribution: Known in the western Pacific from Taiwan to the Philippines. Genus Zenocentrotus H. L. Clark, 1932 The genus is characterized by a more or less elongated test, the long axis leading through ocular plate IV and genital plate 1, and coarse, distally flattened spines. Test: Low hemispherical. Apical system: Ocular plates more or less broadly exsert, all plates densely set with small tubercles; madreporite enlarged. Ambulacra: 8–11 pore pairs per plate, around the ambitus arranged in a double arc or forming a broad irregular band; single large primary tubercle to a plate. Interambulacra: Around the ambitus one large primary tubercle per plate flanked by almost equal-sized secondaries; narrow median zone with small secondaries in a zigzag line. Peristome: Elongated; buccal plates with a few small club-shaped spines, buccal membrane with several embedded plates; buccal notches moderately deep. Spines: Primaries stout, in diameter round, elliptical, flattened, or facetted; fringe-like surrounding the margin and downward directed, in large specimens up to 40 mm long, much shorter at the aboral side; orally more flattened, at the peristome small and inconspicuous; small spines slender; secondaries clavate.

316 

 4.2 Subclass Euechinoidea Bronn, 1860

Two species belong to this genus, which are very similar. Zenocentrotus kellersi A. H. Clark, 1931. Tonga Islands, littoral. Zenocentrotus paradoxus A. H. Clark, 1931. Tonga Islands, littoral. Mortensen (1943) assumed they were probably wide­ spread in the South Pacific. Differences: In Zenocentrotus paradoxus, the widening of the phyllodes at the peristomial edge and the duplication of the pore pairs is less developed than in Z. kellersi. Zenocentrotus kellersi A. H. Clark, 1931 (Fig. 4.215 A–D) The largest length of the test barely reaches 70 mm. Ambulacra: 8 to 11 pore pairs per plate, irregularly arranged or in a broad band, in large specimens distinct double arcs around the ambitus; on oral side wide phyllodes. Color: The large spines are olive brown to purplish, on the oral side olive green with purple ends, the small spines greenish. The white test show slight greenish shades. Zenocentrotus is similar to Heterocentrotus but differs in having more slender primary spines, which on the aboral surface are tapered distally, not truncated. The denuded test is distinguished by the arrangement of the ambulacral primary tubercles: they form regular rows from the peristome to the apical system. Zenocentrotus paradoxus A. H. Clark, 1931 (Fig. 4.215 E–G) Test: Seems to reach barely 40 mm in length. Ambulacra: Usually 10–11 pore pairs per compound plate, sometimes tending to form a duplication of arcs; on oral side slightly wider pore zones. Spines: Longest around the ambitus, a little less than half the diameter of test; flattened and widened distally with rounded ends; aboral spines much shorter and not flattened; oral spines slender, spatulate. Color: Spines of uniform dark olive, the ambital and oral ones with reddish ends mainly on the lower side of the spine. Distribution: Known only from the Tonga Islands, apparently restricted to the littoral zone. Zenocentrotus is closely related to Colobocentrotus, Heterocentrotus, and Podophora. This clade is well adapted to a life in the surf zone. Heterocentrotus has more thickened, longer spines, but the bare tests are undistinguishable. In Colobocentrotus and Podophora, the spines are transformed to a more or less closed pavement covering the whole aboral side.

4.2.9.6 Family Parechinidae Mortensen, 1903 This family includes four genera, which are common mostly in the littoral zone of temperate waters: Loxechinus Desor, 1856. West coast of South America; monospecific. Paracentrotus Mortensen, 1903. North and South Atlantic, Mediterranean; two species. Parechinus Mortensen, 1903. South Africa; monospecific. Psammechinus L. Agassiz & Desor, 1846. North Atlantic and Mediterranean; two species. Genus Loxechinus Desor, 1856 Loxechinus albus Molina, 1782 (Fig. 4.216) Test: Round or slightly pentagonal, rather low, flattened above and below; only slightly depressed toward the peristome; diameter may reach 120 mm. Apical system: Mostly all ocular plates exsert, but sometimes I and V or IV and V may be insert; genital plates narrow and broad, madreporite much enlarged; distal part of plates covered by small tubercles, larger ones at the inner edge; periproctal plates with tubercles. Ambulacra: Nearly as broad as interambulacra, at the ambitus becoming much broader toward the peristome; interporiferous zone almost as broad as 1 pore zone; pore pairs in arcs of 7–9, rather erect near the apical system, subhorizontal on the oral side, separated by oblique rows of small tubercles; two series of primary tubercles, inner secondaries alternating, in large specimens inner series as large as primaries. Interambulacra: One primary tubercle in the middle of each plate, conspicuously larger than in ambulacra, decreasing strongly in size toward the peristome, but scarcely toward the apical system; much smaller flanking secondaries in more or less regular horizontal rows; densely distributed, very small miliary tubercles. Peristome: Rather small, not reaching a third of diameter of test; shallow, vertical buccal notches; small plates without spines scattered over the buccal membrane. Spines: Short and rather stout, the primary spines considerably longer than the secondaries, with blunt, distal ends. Color: The primary spines are reddish brown, more or less with a lighter tip, the secondaries uniformly greenish. The denuded test is green, the median areas of the plates show more or less a purplish, or brownish tint, the tubercles being white. The oral side is much lighter. Distribution: Loxechinus albus is restricted to the west coast of South America from Peru to the Strait of Magellan. It is mainly a littoral form, but also known to depths of 85 m.

4.2.9 Order Camarodonta Jackson, 1912 



B

A

C

F

 317

D

E

G

Fig. 4.215: (A–D) Zenocentrotus kellersi. Close-up of aboral side partly with spines, length 66 mm, width 55 mm; Tonga Islands. ZMH. (B) Oral side. The primary and secondary spines are thickened, the small miliaries slender and distally slightly truncated. The widened pore zones are set with numerous strong tube feet. (C) Ambital ambulacral plates. (D) Adoral ambulacral plates. (E–G) Zenocentrotus paradoxus. (E) Denuded side of test, diameter 38 mm; Ninafoou, Tonga Islands. ZMUC ECH 274. (F) Aboral side with spines. (G) Adoral part of ambulacrum. Scales: (C) 5 mm; (D) 3 mm; (G) 4 mm (Mortensen 1943).

318 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

Fig. 4.216: Loxechinus albus. (A) Aboral side of test, diameter 62 mm; Caldera, Chile. The aboral ambulacra are as broad as the interambulacra. (B) Oral side: at the peristome the interambulacra are narrow and the tubercles are small. (C) Aboral side with spines, diameter of test ca. 50 mm; Peru. ZMH. The reddish brown primary spines are conspicuously longer than the green secondaries. (D) Oral side: the tube feet are strongly developed, whereas the spines decrease in size toward the peristome.

Biology: This species is strongly captured for human food, the formerly large populations are greatly diminished. The roe is exported to East Asia. Loxechinus albus is often infested by the parasitic crab Fabia chilensis. But in contrast to Caenocentrotus

gibbosus, the tests are not deformed, probably because the plates are stronger than in C. gibbosus. Remarks: Loxechinus albus is distinguished from Pseudechinus magellanicus by its larger size and the number of pore pairs per arc: the former having 7–9 pairs, the latter only 3.

4.2.9 Order Camarodonta Jackson, 1912 



At first sight, the greenish tests of these Atlantic/ Mediterranean species look very similar. The most common of them differ in the following characteristics: Parechinus angulosus

Paracentrotus lividus

Psammechinus Psammechinus miliaris microtuberculatus

Pore zones broad

Five pore pairs to each ambulacral plate

Pore zones narrow

Pore pairs in three vertical series

Pore zones narrow Pore pairs in steep arcs of three

Pore pairs in steep arcs of three

Test green, more or less with radiating patterns

Test more or less uniformly green

Test uniformly green or with reddish or purplish median zones

Test green with lighter pore zones

Buccal membrane with some few scattered plates

Buccal membrane with small scattered plates

Buccal membrane densely set with small plates, membrane still visible

Buccal membrane with very densely packed, overlapping plates

Genus Paracentrotus Mortensen, 1903 Test: Regularly hemispherical, outline round. Apical system: Usually dicyclic, rarely with ocular plate I insert. Ambulacra: 5 pore pairs per plate forming oblique rows separated by a secondary tubercle; one primary tubercle to each compound plate. Interambulacra: One large primary tubercle per plate nearly equal-sized from peristome to apex. Spines: Slender, in length half the test diameter. The genus consists of two species: Paracentrotus gaimardi Blainville, 1825. South Atlantic, Brazil, and West Africa. Paracentrotus lividus Lamarck, 1816. North Atlantic and Mediterranean. Usually, they can be distinguished by the number of pore pairs: Paracentrotus gaimardi has 4, P. lividus mostly 5. Paracentrotus gaimardi Blainville, 1825 (Fig. 4.217 A–C) This species is very similar in test structure and spination to Paracentrotus lividus. The main differences are as follows: Test: Diameter not much more than 40 mm. Apical plates: Often, but not always, with fine radiating striation.

 319

Ambulacra: Mostly with 4 pore pairs in one arc, but that is not a constant feature, rarely there may be found 5 pore pairs. Distribution: Paracentrotus gaimardi occurs in Brazil from the region of Rio de Janeiro to the north and along the African coast from Angola to the Gulf of Guinea. It seems to be a littoral form. Remarks: This species differs from Parechinus angulosus, distributed also in southern Africa, in having 4 to 5 pore pairs per plate. Parechinus angulosus has only 3. Paracentrotus lividus Lamarck, 1816 (Fig. 4.217 D–F) Test: Low hemispherical or with flattened upper and underside; maximum diameter 70 mm. Apical system: Genital plates tuberculated along inner edge, smooth distally; ocular plates usually widely exsert; periproctal plates often rather few and large, rarely with tubercles. Ambulacra: 5 pore pairs in each arc on the upper side, 4 to 3 on the oral side, no widening; primary tubercles in two regular series, of about same size as interambulacral ones; small secondary tubercles alternating in the median zone; remainder of plates densely set with very small tubercles or granules as in interambulacra. Interambulacra: Two regular series of subcentral primary tubercles, flanked on either side by one or two subequal secondaries more or less regularly arranged. Peristome: More or less sunken; membrane with small scattered plates, buccal plates forming a closed ring or separated, notches broad and shallow. Spines: Rather strong, slightly tapering to a blunt distal end, finely striated; length not much shorter than half the test diameter in adults, relatively longer in smaller tests. Color: The spines vary from purplish or brown to a more or less dark green. The test is more or less uniformly greenish, the apical system mostly darker. Biology: Paracentrotus lividus is a rock borer. At some places, along the west coast of Ireland and France, the rocks are honeycombed by it, the holes lying side by side. In the Mediterranean, no boring has been reported, here they live in niches between the boulders or in existing crevices. It might depend on the tide flow, which is strong in the Atlantic, but rather weak in the Mediterranean (Mortensen). Generally, these sea urchins cover themselves with pieces of algae or shells for protection against direct light or predators. This species is collected for food, the gonads of males and females are thought to be a delicacy. Recently, cultivation of this species in aquafarms has been started.

320 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

D

F

F

E



Distribution: Paracentrotus lividus is known through­out the whole Mediterranean, in the Atlantic from Ireland and the English Channel to West Africa, and from the Cape Verde Islands, the Canaries, Madeira, and the Azores from the tide zone to a depth of 100 m. Remarks: The setting regions of Paracentrotus lividus and Psammechinus miliaris overlap in west and southwest Europe. These species can be distinguished by the length of their spines, which in P. miliaris are very short, about 5 mm. In P. lividus, spines can reach almost half the diameter of test. In the Mediterranean, P. lividus overlaps with Psammechinus microtuberculatus, which also has shorter spines. The naked test differs in the number of pore pairs per arc, Psammechinus having 3 and P. lividus 5. Genus Parechinus Mortensen, 1903 The genus is monospecific. Parechinus angulosus Leske, 1778 (Fig. 4.218) Test: Regularly hemispherical, circumference round or rounded pentagonal; peristomial edge sunken; maximum diameter 60 mm. Apical system: Ocular plates all exsert or I and V insert; genital pores often at distal edge of plates; periproctal plates in adults with tubercles. Ambulacra: Broad pore zones, nearly as wide as interporiferous zone, the pore pairs in strongly oblique arcs of three, thus forming three distinct, vertical series; primary tubercles in very regular, dense series; secondaries irregularly arranged, numerous very small tubercles. Interambulacra: Primary tubercles not forming dense series as in ambulacra, separated by some small tubercles, but regular as well; larger secondaries more or less irregular, not reaching size of primaries; space between them densely covered by very small tubercles. Peristome: Rather small, rounded triangular buccal plates, usually circle of ten equidistant plates; membrane with only some scattered plates; notches small, but distinct. Spines: Rather slender, primary spines hardly more than 12–13  mm, but in littoral specimens, often shorter and more robust. Color: The variation of color in the spines is extraordinary, dark purple, green with violet or intense red with whitish tips or even uniformly red or whitish. The test is usually uniformly greenish or with purplish brown, radiating

4.2.9 Order Camarodonta Jackson, 1912 

 321

median zones; sometimes, the tubercles may be purplish in specimens with spines of that color. All kinds occur in mixed populations. Biology: Parechinus angulosus is found on rocky shores, often in rock pools or between stones. It covers itself with fragments of algae, shells of limpets, or other materials. Distribution: This species is known only from South Africa, from Angola on the west coast, round the Cape and northward to Mozambique. It lives in the littoral zone to depths of 180 m. Remarks: Parechinus angulosus with 3 pore pairs per plate differs from Paracentrotus gaimardi, having 4 to 5 pore pairs. Genus Psammechinus L. Agassiz & Desor, 1846 The genus with its two species is very common at the coasts of West Europe and in the Mediterranean. Test: In outline round to subpentagonal, in profile low depressed. Apical system: Dicyclic with ocular plates all exsert. Ambulacra: 3 pore pairs to a plate forming a vertical band, one large primary tubercle and to either side secondaries; a distinct row of smaller ones within the pore zones. Interambulacra: One large primary tubercle flanked by smaller secondaries. Peristome: Buccal notches small, no phyllodes. Spines: Stout, distally pointed, in length less than half the test diameter. Psammechinus microtuberculatus Blainville, 1825 Psammechinus miliaris P. L. S. Müller, 1771 Remarks: In Psammechinus microtuberculatus, the test has light pore zones; in P. miliaris, the test is uniformly green, at most with reddish or purplish median zones. The spines of Psammechinus are much shorter than those of Paracentrotus lividus. The naked test has 3 pore pairs in an arc in contrast to P. lividus with 5. Psammechinus microtuberculatus Blainville, 1825 (Fig. 4.219 A–C) Test: Low hemispherical; peristome only slightly sunken; maximum diameter 35 mm, exceptionally 40 mm. Apical system: Genital and ocular plates with few but relatively large tubercles, especially at the periproctal edge; periproctal plates numerous and usually naked.

◂ Fig. 4.217: (A–C) Paracentrotus gaimardi. (A) Aboral side of test, diameter 33 mm; Luanda, Angola, 2 m deep. (B) Close-up of aboral

side: 4 and 5 pore pairs to a plate are developed in one column. Scale: 5 mm. (C) Aboral side with spines, test diameter about 44 mm; Luanda, Angola. The spines are solid and rather long. (D–F) Paracentrotus lividus. (D) Aboral side of test, diameter 51 mm; Crete, Greece. The series of tubercles are very regular. (E) Close-up of aboral side: the plates are densely covered by small tubercles and granules. Scale: 5 mm. (F) Aboral side with spines, diameter of test about 50 mm; Brittany, France. The spines may be green or more purple.

322 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

D

Fig. 4.218: Parechinus angulosus. (A) Aboral side of test, diameter 37 mm; False Bay, South Africa. The primary tubercles of the ambulacra are developed as regular, very dense series. The pore zones form a broad band. (B) Oral side: the underside of the test is whitish, the buccal notches small, but distinct. (C) Aboral side with spines, diameter of test about 40 mm; Cape Town, South Africa. ZMH. (D) Oral side with spines, Cap Agulhas, South Africa. The spines may be greenish, purplish, lavender, or brick red. The tube feet are thick and long.

Ambulacra: Two regular series of primary tubercles, which on the upper side are smaller than the interambulacral ones, but on the oral side almost reach them in size; secondary tubercles more or less irregular. Interambulacra: Two regular series of primary tubercles, flanked on both sides by smaller secondaries.

Peristome: Plates of the buccal membrane densely set with imbricating platelets, membrane not being visible; buccal plates widely separated; buccal notches very shallow. Spines: Very short and relatively slender, tapering to a blunt distal end.

4.2.9 Order Camarodonta Jackson, 1912 



A

 323

B

C

E

D

Fig. 4.219: (A–C) Psammechinus microtuberculatus. (A) Close-up of aboral side, diameter of test 31 mm; Cyprus, Mediterranean. The pore zones are conspicuously whitish forming radial stripes. Scale: 5 mm. (B) Close-up of peristome. The plates are imbricating. (C) Aboral side, diameter with spines 38 mm; Greece. The test is set with longer primary and secondary spines and a coat of densely distributed short green miliary spines. The pore zones are conspicuously lighter. (D, E) Psammechinus miliaris. (D) Close-up of aboral side, diameter of test 33 mm; Limfjord, Denmark. The pore pairs in the ambulacra are arranged in arcs of three. The white tubercles are very conspicuous. (E) Aboral side, diameter with spines 34 mm; Lymfjord, Denmark. The spines are short and stout with blunt distal ends.

324 

 4.2 Subclass Euechinoidea Bronn, 1860

Color: The test is green with whitish pore zones. The primary and secondary tubercles are brownish, the numerous short miliaries green. The thick buccal plates are green as well. Distribution: Psammechinus microtuberculatus is known only from the Mediterranean at depths from 4 to 100 m. Psammechinus miliaris P. L. S. Müller, 1771 (Fig. 4.419 D, E) This species is very similar to Psammechinus microtuberculatus. It differs by the following features: Test: Maximum diameter 50 mm. Peristome: Plates of the buccal membrane more or less densely set with platelets, the membrane always being visible. Spines: Short and stout, in a specimen of 28 mm diameter only 4 mm. Color: The spines are greenish with violet or reddish distal ends; the test may be uniformly green or more or less distinctly reddish or purplish along the median spaces of both areas, rarely in the whole reddish. The oral side, the buccal membrane and all tubercles are whitish. Biology: Psammechinus miliaris is an omnivore feeding all kinds of organism that it can grasp, hydroids, bryozoans, and worms, but also echinoderms, sponges and crustaceans. It covers itself with pieces of algae, pebbles, or shells to protect itself against direct light. Distribution: This species is known from Norway (Trondheim) to the North Sea and the Kattegat, from Iceland to Morocco and the Azores. It is not found in Greenland or the West Atlantic. Psammechinus miliaris lives from the tide zone to a depth of 100 m. In the Danish fjords, a dwarf-form exists, which does not exceed 35 mm in test diameter. The Lymfjord in North Jylland is connected to the North Sea and the Kattegat only by narrow openings. It is likely that the salinity is reduced, and the sea urchins are not growing as large as in the open sea. Literature: Mortensen 1927.

4.2.9.7 Family Strongylocentrotidae Gregory, 1900 This family differs from the other families in the Echinoidea by the shape of the valves of the pedicellariae. The pore pairs in the ambulacra form distinct sickle-shaped arcs or oblique rows. The genera live exclusively in cold to temperate waters of the northern hemisphere. In the last years, the composition of the family often changed. Mortensen (1943) included Allocentrotus, Hemicentrotus, Strongylocentrotus.

Dartnall (1971) listed his new Pachycentrotus bajulus in the Strongylocentrotidae. Jensen (1981): Allocentrotus, Hemicentrotus, Strongylocentrotus. Tatarenko & Poltaraus (1993): Strongylocentrotus franciscanus and S. nudus united to Mesocentrotus. Smith (2005): Allocentrotus, Hemicentrotus, Loxechinus, Pseudocentrotus, Strongylocentrotus. Pearse & Mooi (2007): Allocentrotus synonymized to Strongylocentrotus. And the discussion has not yet be finished (Mooi 2015, personal communication). Following the WoRMS database, there are four genera in the Strongylocentrotidae: Hemicentrotus Mortensen, 1942. Monospecific. Mesocentrotus Tatarenko & Poltaraus, 1993. Two species. Pseudocentrotus Mortensen, 1903. Monospecific. Strongylocentrotus Brandt, 1835. Seven species. Literature: Boolootian et  al. 1959; Jensen 1981; Shigei 1986; Biermann et al. 2003; Matsuoka 1987; Pearse & Mooi 2007; Vinnikova & Drozdov 2011; Ullrich-Lüter et al. 2011. Genus Hemicentrotus Mortensen, 1942 The genus contains a single species that is characterized by very densely distributed small tubercles carrying a short coat of spines. Hemicentrotus pulcherrimus A. Agassiz, 1863 (Fig. 4.220) Test: Solid; upper side low hemispherical or flattened, circumference round or rounded pentagonal, oral side flattened; the peristome slightly depressed; diameter up to 50 mm. Apical system: Madreporite much enlarged, ocular plates I and V broadly insert; genital pores at the outer edge of the genital plates and rather large; ocular and genital plates densely covered by tubercles, largest at the inner edge; most of the periproctal plates carrying a single tubercle, anal opening eccentric. Ambulacra: As broad as interambulacra at the ambitus and broader at the peristomial edge; pore pairs in wide, oblique rows of four, forming four vertical series; sometimes, the two outer ones closer together than the inner ones; the oblique rows separated by a series of small tubercles; primary tubercles small and close to each other; secondaries not much smaller, in more or less regular vertical series; remaining space densely covered by still smaller miliaries. Interambulacra: Primary tubercles not much larger than in ambulacra, forming two well defined vertical series; secondaries only slightly smaller, in more or less regular horizontal or slightly oblique rows; remaining space covered by miliary tubercles.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

B

D

 325

E

Fig. 4.220: Hemicentrotus pulcherrimus. (A) Half an ambulacrum: the pore zones are broad, the pore pairs forming four vertical series. The areoles of the primary tubercles are a little eccentric. Scale: 1 mm (Mortensen 1943). (B) Aboral side of test, diameter 43 mm; Chiba Peninsula, central Japan. The test shows a radiating pattern, the pore zones are of lighter green than the median areas, and the tubercles almost white. (C) Oral side of test: there are no phyllodes. (D) Aboral side, diameter with spines 41 mm, height 21 mm; Izu Peninsula, central Japan, Pacific. The spines show a tendency to part along the median areas. (E) Oral side with spines: the color is gray, greenish to purple, irregularly distributed.

Peristome: Small, not reaching a third of test diameter; buccal plates equally spaced; notches small and without tags; membrane with numerous small plates. Spines: Very short, scarcely longer than 5–6 mm, forming a uniform, dense coat; in dried specimens the spines often part at median areas. Color: The spines are usually dark green, but some may be grayish white, either single ones or several or all of them and sometimes they are banded in reddish brown. All variations may occur in one individual. The bare test is mostly greenish, more or less lighter along the pore zones. The oral side is a dirty white, contrasting to the dark buccal membrane. Sometimes the median areas may be brownish or the whole test may be purplish with green median areas.

Distribution: Hemicentrotus pulcherrimus occurs in Japan, from Honshu and Kyushu along the Pacific coast, in the Japanese Sea, and also in northern China. It lives in the littoral zone and down to a depth of 45 m. Remarks: This species is easily distinguished from all other regular sea urchins of the region by the small tubercles, densely covering the whole surface, set with a coat of uniform, short spines. The 4 pore pairs per plate are unique in the Strongylocentrotidae. Genus Mesocentrotus Tatarenko & Poltaraus, 1993 Two species of Strongylocentrotus, S. franciscanus (A. Agassiz, 1863) and S. nudus (A. Agassiz, 1863) were united and made a genus of its own. This taxon is based on

326 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

D

E

C

F

Fig. 4.221: (A–C) Mesocentrotus franciscanus. (A) Aboral side of test, diameter 132 mm; California, USA. (B) Side view: many miliary tubercles are scattered around the primaries and secondaries. (C) Plates of half an ambulacrum: the sickle.shaped arcs of pore pairs are very long. (D–F) Mesocentrotus nudus. (D) Aboral side of test. Diameter 71 mm; Chiba Peninsula, Japan. The primary tubercles are distinctly larger than the secondaries. (E) Oral side: the buccal notches are broad and shallow. The pore zones are not widened. (F) Aboral side with spines, diameter of test 66 mm; Hokkaido, Japan. The dark purplish spines are slender, tapering to a blunt end. In more exposed water they may be shorter and stouter.

results of a DNA-DNA hybridization. Mesocentrotus differs morphologically from Strongylocentrotus by its generally longer spines. Their core of meshwork is larger and denser, and the surface of the spines is covered by finer wedges. Mesocentrotus franciscanus A. Agassiz, 1863 (Fig. 4.221 A–C) This species, the “red sea urchin” of the west coast of North America, reaches a test diameter of 160 mm, with spines, it may be 300 mm. It is thus one of the largest echinoids. Test: Very strong, more or less high hemispherical, oral side flattened. Apical system: Dicyclic with ocular plates I and V broadly insert; madreporite enlarged. Ambulacra: On the peristomial edge, broader than interambulacra; one large tubercle per plate, smaller flanking secondaries on both sides; 8–9 pore pairs to a plate, more rarely 6 or 10, forming steep arcs on the upper side, oblique series on the oral side; pore zones uniform in width from the aboral side to the peristome.

Interambulacra: One primary tubercles and generally smaller secondaries forming horizontal series on a plate; size of primaries uniform from peristome to apex. Peristome: Relatively small; large buccal notches, median ambulacral edge also indented. Spines: Primaries fine and nearly or longer than half the test diameter; generally larger than secondaries. Color: In life, the test is dark brown or purplish and the spines are orange, reddish to brown, purplish or black. The bare and cleaned test is light purplish, or whitish with a purplish tint along the pore zones. On life specimens the peristome is never green, in very young ones rather orange. Distribution: This species is known in the northern Pacific from the Aleutian Island southward to north Japan and along the American coast from Sitka, Alaska, to Baja California. Depths of 0 to 125 m. Ecology: Large quantities of this species are gathered along the west coast of America to be exported to East Asia. The roe is a famous delicacy for gourmets. Overfishing,

4.2.9 Order Camarodonta Jackson, 1912 



A

 327

B

C

Fig. 4.222: Pseudocentrotus depressus. (A) Aboral side of test, diameter 66 mm; Misaki, Japan. (B) Oral side: the pore pairs are less numerous than aborally, but more densely set, the pore zones are widened. (C) Side view: in profile, the test is very depressed The oral side is quite flat.

however, has had severe effects on the ecosystem as the sea urchins graze on algae, keeping the growth, e.g. of the large kelp in balance. Mesocentrotus nudus A. Agassiz, 1863 (Fig. 4.221 D–F) Very closely related to Mesocentrotus franciscanus. Test: Strong, diameter may reach 100 mm. Ambulacra: With 6 pore pairs to a plate, rarely with 7. Color: The spines are dark purplish, almost black, sometimes more greenish olive or dark grayish. The bare test is greenish gray with a purplish tint, especially on the apical system or it may be almost entirely purplish with lighter tubercles. Distribution: This species is restricted to northern Japan from Hakodate to Sagami Bay along the Pacific coast and in the Japan Sea southward to the Tsushima Islands. It lives among boulders from the shore to a depth of 180 m. Remarks: Mesocentrotus nudus differs from Heliocidaris crassispina, which has a very similar appearance, by the number of pore pairs: M. nudus has 6, rarely 7, in contrast H. crassispina, which has 8, rarely 7 or 9. Mesocentrotus nudus lacks widened phyllodes, which are well developed in H. crassispina. With spines, the two species are hardly to distinguish, in M. nudus they may be usually shorter.

Genus Pseudocentrotus Mortensen, 1903 The monospecific genus is characterized by a low test being broadly depressed on aboral and totally flat on oral side. Pseudocentrotus depressus A. Agassiz, 1863 (Fig. 4.222) Test: Circumference round or rounded pentagonal; maximum diameter 85 mm. Apical system: Dicyclic with ocular plates I and V broadly insert; genital and ocular plates densely tuberculated; madreporite considerably larger than other plates; anal opening eccentric. Ambulacra: Broad, at the peristome wider than interambulacra; 6–7 pore pairs to a compound plate forming an oblique row, on oral side wide phyllodes with fewer and more crowded pore pairs; one primary tubercle per plate, not as large as interambulacral ones; secondaries smaller, forming one alternating series or two distinct ones; quite a number of tubercles in the pore zones, the largest in a more or less regular vertical row. Interambulacra: Two prominent vertical series of primary tubercles, secondaries in vertical rows as well, but smaller; plates covered by more or less densely distributed miliary tubercles, no naked median space; at the peristomial edge much smaller than the ambulacra.

328 

 4.2 Subclass Euechinoidea Bronn, 1860

Peristome: Buccal notches with conspicuous tags; buccal membrane with small, scattered plates. Spines: Primaries moderately long and slender with blunt end, on oral side much shorter; secondaries fine and distinctly smaller than primaries, many short scattered militaries. Color: In life, the primary spines are reddish brown, pinkish, or rarely light purplish, the test is dark brown. The bare test is grayish pink or light purple with whitish pore zones. Distribution: This species is endemic to Japan reported from northern Honshu to southern Kyushu. It lives from the intertidal zone to a depth of 50 m. Remarks: Pseudocentrotus depressus was included in the family Toxopneustidae, but biochemical work has shown (Matsuoka 1987) that this species is closer related to the Strongylocentrotidae. It differs from the species of Strongylocentrotus by the widened phyllodes and by the brown color of the spines, in the latter, being dark purplish. Heliocidaris crassispina, which also has a purplish test, is distinguished by the more numerous pore pairs per plate, usually 8 as opposed to 6 or 7 in P. depressus. Genus Strongylocentrotus Brandt, 1835 The species of Strongylocentrotus are widely distributed in temperate to cold waters in the northern hemisphere from the littoral down to a depth of more than 1,500  m. Only Strongylocentrotus purpuratus and the deep sea species Strongylocentrotus fragilis have expanded to Baja California into warmer water. M. Jensen (1981) dealt with this group exhaustively and separated the species on the base of differences in the shape of their pedicellariae and their tubercles, the fine structure of their teeth and in the number of wedges on the spines – features that are visible only under highpower magnification. The species may be also distinguished by their color – which is very variable in some species  – and by their geographical distribution – which often overlaps. Consequently, the distinction is rather unsatisfactory. Eight species are listed in the genus Strongylocentrotus (WoRMS): Strongylocentrotus djakonovi Baranova, 1957. Strongylocentrotus droebachiensis O. F. Müller, 1776. Strongylocentrotus fragilis Jackson, 1912. Strongylocentrotus intermedius A. Agassiz, 1863. Strongylocentrotus pallidus Sars, 1871. Strongylocentrotus polyacanthus A. Agassiz & H. L. Clark, 1907.

Strongylocentrotus pulchellus A. Agassiz & H. L. Clark, 1907. Strongylocentrotus purpuratus Stimpson, 1857. The genus Strongylocentrotus is characterized by the following features: Test: Solid and usually round, generally low hemispherical or with flattened aboral side. Apical system: Hemicyclic with ocular plates I and V broadly insert; enlarged madreporite. Ambulacra: One large primary tubercle per plate and smaller flanking secondaries on both sides; number of pore pairs between 5 and 10 according to the species; pore zones not widened on the oral side; ambulacra in the whole uniform in width from the adoral side to the peristome; where they are usually wider than, or at least as wide as the interambulacra. Interambulacra: One primary tubercle and generally smaller secondaries forming horizontal series on a plate; in some species, more uniform; primary tubercles of same size from the apex to the peristome. Spines: Fine and not longer than half of test diameter; primary spines generally larger than secondaries, sometimes more uniform spination. Remarks: In the northeast Atlantic, Strongylocentrotus differs from Psammechinus miliaris by the number of pore pairs having 5 to 7 instead of three in the latter. It differs from Paracentrotus lividus in having the posterior ocular plates broadly insert; in P. lividus, has a dicyclic apical system. In Japanese waters, Strongylocentrotus is distinguished from Heliocidaris crassispina by the lack of widened phyllodes. It differs from Pseudocentrotus depressus also by the lack of phyllodes and by the color of the spines: in Strongylocentrotus, they are more purplish to greenish, in the former they are rather reddish brown. Strongylocentrotus djakonovi Baranova, 1957 Jensen (1981) synonymized this species with S. polyacanthus. However, it is listed in WoRMS. Strongylocentrotus droebachiensis O. F. Müller, 1776 (Fig. 4.223) Ambulacra with 5 pore pairs in one arc, occasionally 6 pore pairs. Test: Maximum diameter may reach 100 mm. Color: The test is purple to dark violet, more or less vividly colored and with more or less radial patterns, but it may also be uniformly greenish. The spines vary from white with a tinge of violet to yellowish green. Distribution: Northeast Atlantic from Franz-Josef-Land to the North Sea and the western Baltic Sea; along the Arctic

4.2.9 Order Camarodonta Jackson, 1912 



A

 329

B

C

D

Fig. 4.223: Strongylocentrotus droebachiensis. (A) Ambulacral plates with 5 and 6 pore pairs. Scale: 2 mm (Mortensen 1943). (B) Aboral side of test, diameter 34 mm; Lofoten Islands, Norway. The primary tubercles are distinctly larger than the secondaries. (C) Oral side: the buccal notches are small. (D) Aboral side, diameter with spines 56 mm; Bergen, Norway. The spines are rather short, stout, and of uniform size. It is likely that this specimen lived in a habitat with heavy water motion. In more sheltered waters, the spines are more slender and the primaries are distinctly longer than the secondaries.

coasts of Russia to the Chukchi Sea, in the North Pacific from the Bering Sea southward to the Japan Sea and to southern Oregon, USA, along the Arctic coasts of Canada eastward to Greenland, and in the northwest Atlantic to the Chesapeake Bay, USA, in the south.

Strongylocentrotus fragilis Jackson, 1912 (synonym Allocentrotus fragilis Jackson, 1912) (Fig. 4.224) Test: Thin and fragile; in outline round; low hemispherical, oral side broadly flattened, depressed toward the peristome; maximum diameter approximately 100 mm.

330 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

Fig. 4.224: Strongylocentrotus fragilis. (A) Aboral side of test, diameter 71 mm; California, USA. The secondary tubercles are very small and inconspicuous aborally. (B) Oral side: primary and secondary tubercles are of subequal size orally. (C) Close-up of aboral side, diameter 58 mm; Oregon, USA. The pore pairs are arranged in dense oblique arcs of five. Scale: 10 mm.

Apical system: Usually ocular plates I and V insert, but occasionally either only I or only V insert, or even all insert; madreporite much enlarged and flat; numerous small tubercles distributed over the plates. Ambulacra: Pore pairs in wide, oblique arcs of five; each arc separated from the next one by a row of small tubercles; primary tubercles half the size of interambulacral ones, in two close-set vertical series; secondaries inconspicuous aborally; below the ambitus almost as large as primary tubercles, but becoming much smaller toward the peristome. Interambulacra: Primary tubercles small, yet double the size of ambulacral ones; forming two vertical series in the middle of the plates; secondaries well developed on the oral side, with two or more series parallel to the primaries, but very small and inconspicuous aborally. Peristome: Buccal plates in a circle of almost equidistant plates; membrane otherwise almost bare, with only a few small, thick plates; notches broad, but not deep. median suture in ambulacra also more or less indented.

Spines: Very slender and delicate, not reaching more than one fourth of test diameter in adult, but as long as diameter of test in young specimens. Color: The spines are reddish at the base, more whitish toward their distal end. The oral spines are much paler. The bare test may vary from orange red to deep purple, showing a distinct radiating pattern. Often, there are light, transversely elongated spots below each primary tubercle on the interambulacral plates. The oral side is whitish. Biology: Strongylocentrotus fragilis feeds on detritus living often in large numbers on rocky and fine sandy substrates. Distribution: This species is restricted to the west coast of North America, from Vancouver Island to Baja California. It lives in depths of 30 to more than 1,200  m, most abundant between 100 and 800 m, on fine sand to clayish silt. Remarks: Strongylocentrotus fragilis can be immediately distinguished from the other species of Strongylocentrotus and Mesocentrotus by its vivid reddish color.

4.2.9 Order Camarodonta Jackson, 1912 



Strongylocentrotus intermedius A. Agassiz, 1863 In contrast to the other species of Strongylocentrotus, the primary tubercles are not much larger than the secondaries, the spines forming a coat of almost uniform length. Test: Low, flattened above and below. Ambulacra: Pore zones in broad bands, 5–6 pore pairs in low arcs. Color: The test is dark violet, the spines olive green. Distribution: The species is reported living in large numbers around Sachalin, Russia, and Hokkaido, Japan, at depth of 0–35 m among boulders. Strongylocentrotus pallidus Sars, 1871 (Fig. 4.225) Ambulacra: 6–7 pore pairs per arc, sometimes 5 or 8. Color: The test varies from pale green, greenish brown to reddish purple, oral side lighter; primary spines olive green to olive brown, sometimes red violet; at the base generally darker than distally. Distribution: This species is circum-boreal like Strongylocentrotus droebachiensis being widely spread along the Arctic, the Asian coast southward to Korea, west coast of America to Oregon, east coast of America to Massachusetts Bay, European coast southward to Oslofjorden and the Shetland Islands in depths of 5 to 1,600  m. Jensen (1981) reported that the species is more abundant in the Arctic regions than in more temperate waters. Off Thule

A

 331

in West Greenland, it constitutes almost 90 % of the sea urchins. Remark: Strongylocentrotus pallidus resembles very much S. droebachiensis. Mortensen (1903, 1943) treated S. pallidus as a synonym of S. droebachiensis. Both species live in almost the same geographic regions. In WoRMS, they are listed as two distinct species. Strongylocentrotus polyacanthus A. Agassiz & H. L. Clark, 1907 (Fig. 4.226 A, B) Characteristics of the genus. There are 6–7 pore pairs per arc. Distribution: North Pacific Bering Sea, Aleutian Islands southward to Kuril Islands, northwest Pacific, 0 to 45 m. Strongylocentrotus pulchellus A. Agassiz & H. L. Clark, 1907 Ambulacra with 5–6 pore pairs per arc. Distribution: Restricted to the southeastern part of the Bering Sea, Kamtchatka, Kuril Island, Okhotsk, and Japanese Sea in depths between 8 and 225 m, obviously not in the littoral. The species is found on bare rock to muddy sand. Strongylocentrus purpuratus Stimpson, 1857 (Fig. 4.226 C, D, 4.227) Test: Diameter hardly reaching 50 mm.

B

Fig. 4.225: Strongylocentrotus pallidus. (A) Aboral side of test, diameter 37 mm; southwestern Greenland. ZMUC. Typical form with reddish purple test. However, the width of variation in color and appearance of the spines is very large. (B) Oral side with spines, diameter 59 mm; southern Greenland.

332 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

D

C

Fig. 4.226: (A, B) Strongylocentrotus polyacanthus. (A) Aboral side of test, diameter 47 mm; Kurilen Strait. ZMUC. (B) Side view: the pore zones form a broad band. (C, D) Strongylocentrotus purpuratus. (C) Aboral side of test, diameter 42 mm; Humboldt County, California, USA. (D) Oral side: the upper side is green, but the oral side deep purple.

Ambulacra: There may be 7–8 pore pairs per plate, very rarely up to 9. Color: The test is green or purplish, sometimes in one individual. The spines are mostly dark purplish, sometimes with a green base. In dried specimens, the color fades out to lavender. Distribution: This species is known from Sitka, Alaska, USA, to Baja California, Mexico. It lives mostly in exposed areas from the intertidal zone to a depth of 90 m. Biology: The species settle in large numbers on flat rocky banks with crevices and tide pools. The sea urchins are able to erode their hollows actively by means of spines and teeth the shape of their test being adapted to the

shape of the hole. Often they cover their tests with pebbles or pieces of shells against light or predators. Recent research on Strongylocentrotus purpuratus has revealed that echinoids do have special photoreceptor cells (PRCs), with which they are able to discern light and shadow. Ullrich-Lüter et al. (2011) found clusters of PRCs in the tube feet, up to 140 in a single podium, connected to the nervous system of the animal. One cluster is located in the rim of the disc, another cluster lies in a small cup-like depression at the very base of the tube foot stalk, shielded by the opaque calcite skeleton. Depending on the position of the tube foot, oral, ambital, or aboral, the cells perceive shadow or light in a varying angle. The amount of up to 200,000 PRCs per echinoid, depending on size of the

4.2.9 Order Camarodonta Jackson, 1912 



A

 333

B

C

Fig. 4.227: Strongylocentrotus purpuratus. (A) Aboral side with spines, diameter 61 mm; California, USA. (B) Side view of test, diameter 45 mm; Mattole Beach, California, USA. The oral side of specimens may be convex fitting to their shallow grooves. (C) Habitat tide pool, Humboldt Co., California, USA. The sea urchins sit side by side in pits, which they do not leave for grazing. They are sessile, feeding on organic particles that come with the water. Many of the animals have camouflaged themselves with small pebbles or pieces of algae.

animal and number of podia, distributed over the whole surface, suggests that the skeleton function is as a huge compound eye.

4.2.9.8 Family Toxopneustidae Troschel, 1872 This family is common and widespread in tropical waters in the Indo-Pacific and the Atlantic. The species, large forms with a maximum diameter of 150  mm and small ones of barely 8 mm, live predominantly in shallow water. The toxopneustids are characterized by tests with deep and sharply indented buccal notches at the peristomial edge, where the buccal sacs protrude (Fig. 4.228). In the ambulacra mostly 3 pore pairs are developed, in Pseudoboletia, there are 4, and in Sphaerechinus, up to 5. The family contains nine extant genera: Goniopneustes Duncan, 1889. Monospecific, China Sea. Gymnechinus Mortensen, 1903. Four species; Indo-West Pacific. Lytechinus A. Agassiz, 1863. Six species; along the Atlantic and Pacific coasts of tropical and subtropical America, Cape Verde Islands. Nudechinus H. L. Clark, 1912. Eight species; Indo-West Pacific.

Pseudoboletia Troschel, 1869. Four species; IndoPacific, South Atlantic, and Caribbean. Sphaerechinus Desor, 1856. Monospecific; Mediterranean, eastern Atlantic from Denmark to the Gulf of Guinea, Canaries, and Azores. Toxopneustes L. Agassiz, 1841. Four species; Indo-Pacific from East Africa to the west coast of America. Tripneustes L. Agassiz, 1841. Three species; through-out the Indo-Pacific; in the Caribbean and along the west coast of central America. Genus Goniopneustes Duncan, 1889 This genus is characterized by its bare surface. The pore pairs in the ambulacra form a broad band. The inner periproctal plates are white and knob-like. The genus consists of a single species. Goniopneustes pentagonus A. Agassiz, 1872 (Fig. 4.229) Test: High to spherical, of moderate to large size (the gonopores appear at a horizontal diameter of only 27 mm), more or less rounded pentagonal; on the whole thin and fragile. Apical system: Hemicyclic with ocular plates I and V broadly insert; all plates naked except some miliary tubercles; some periproctal plates look like large, white knobs; madreporite inflated.

334 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

Fig. 4.228: (A, B) Deeply indented buccal notches are typical for the Toxopneustidae: (A) Peristomial edge of Toxopneustes pileolus. (B) Peristomial edge of Pseudoboletia maculata: the membrane extends over the peristome spreading at the edge along the notches. Scale: 10 mm.

A

B

Fig. 4.229: (A, B) Goniopneustes pentagonus. (A) Side view of test, diameter 27 mm; China Sea. © NHMUK London (photo by H. Taylor). The test is almost spherical. (B) Aboral side of test, diameter of test 18 mm; China Sea. There are distinct white knobs on the periproctal plates. (C, D) ©NHMUK London (photo by H. Taylor).

Ambulacra: Small primary tubercles on every second or third plate, secondaries very small and scarce; pore pairs in low arcs of three, pore zones forming a broad band; median area naked aborally. Interambulacra: One rather small primary tubercles per plate and a few much smaller scattered secondaries, median area naked aborally. Peristome: Scattered plates carrying pedicellariae on the membrane; large buccal plates in pairs, buccal notches conspicuous.

Spines: Short, about 6  mm at a test diameter of 22  mm, tapering to a blunt end. Color: The test is light reddish, less bright on the naked median areas, with a purplish tint on the ambulacra; tubercles and primary spines white, also the knobs on the periproctal plates; secondary spines grayish purple; buccal membrane dark, buccal plates lighter. Distribution: Known with certainty only from the China Sea at a depth of 50 to 90 m.



Genus Gymnechinus Mortensen, 1903 The genus is characterized in having its ocular plates I and II insert. Test: Small, low hemispherical or flattened aborally; aboral. Apical system: Hemicyclic with ocular plates I and II insert; strongly eccentric, anal opening displaced toward the narrow genital plate 1. Ambulacra: Pore pairs in arcs of three forming a single band; one primary tubercle per plate. Interambulacra: One central primary tubercle per plate, a few secondary tubercles on either side of almost equal size. Peristome: Buccal membrane naked except for buccal plates; notches small but distinct. Spines: Short, scarcely reaching 5 mm. The genus consists of four species, which are widely spread over the Indo-West Pacific. Gymnechinus abnormalis H. L. Clark, 1925. Indian Ocean. Gymnechinus epistichus H. L. Clark, 1912. Malayan Archipelago to northeast Australia. Gymnechinus pulchellus Mortensen, 1904. West Pacific. Gymnechinus robillardi de Loriol, 1883. Indian Ocean. Gymnechinus abnormalis H. L. Clark, 1925 Test: Flat, diameter of holotype 8 mm. Apical system: Hemicyclic, all plates lacking tubercles; periproctal plates very thin. Spines: Short, stout, conspicuously striated. Color: The test and the primary spines are a very pale reddish purple, on the oral side more whitish. In contrast, the pedicellariae and the muscles of the spines are dark brown. Occurrence: The two only known specimens were found at Carcajos Carados(?), Indian Ocean at a depth of 54 m. Gymnechinus epistichus H. L. Clark, 1912 (Fig. 4.230 A–C) Test: Very low hemispherical, more or less flattened aborally; oral side sunken toward the peristome; maximum diameter 26 mm. Apical system: Hemicyclic, anal opening eccentric; plates with a few tubercles. Ambulacra: Pore pairs in low arcs of three, forming a broad band; regular vertical series of primary tubercles near the pore zone, a row of secondary tubercles in the pore zone and also adradially, median area with few scattered secondaries, all much smaller than primaries.

4.2.9 Order Camarodonta Jackson, 1912 

 335

Interambulacra: Below each primary tubercle occurs a small depression in the same color as the tubercles, flanked by two small tubercles. Peristome: Membrane totally naked except the five pairs of very small buccal plates, deep notches. Spines: Short and stout, tapering to a blunt tip. Color: Spines orange or purplish, with white tip; test very variable: white, purplish or orange. Distribution: The species is widespread in the Malayan region to northeast Australia from the littoral to a depth of 63 m. Gymnechinus pulchellus Mortensen, 1904 (Fig. 4.230 D) Characteristics of genus. Apical system: Genital plates usually with only a single tubercle. Spines: Oral spines longer and more densely developed than on the aboral side. Color: Test and spines mainly white, more or less with purplish. Distribution: Indian Ocean, 5 to 50 m. Gymnechinus robillardi de Loriol, 1883 (Fig. 4.230 E, F) This species resembles G. epistichus very much. The diameter may reach 29  mm. It lacks the depressions below the interambulacral primary tubercles seen in G. epistichus, and the spines are rather whitish instead of reddish or purplish. Distribution: Gymnechinus robillardi is found in the Indian Ocean from East Africa to India. Bathymetric range: from the littoral to a depth of about 70 m. Remark: Usually, the colors in Gymnechinus robillardi are brighter than in G. epistichus. Both species have much more secondary tubercles in the interambulacra than G. pulchellus. Genus Lytechinus A. Agassiz, 1863 Test: Small to large, usually low hemispherical with flattened oral side. Apical system: Hemicyclic, mostly ocular plates I and V insert; plates more or less naked; madreporite enlarged. Ambulacra: 3 pore pairs per plate, forming a band, each plate with a primary tubercle, secondary tubercles not in regular series; often naked median areas adapically. Interambulacra: Mostly with conspicuous naked median areas, aboral tuberculation being rather sparse. Peristome: Membrane densely covered by thick plates, distinct buccal notches.

336 

 4.2 Subclass Euechinoidea Bronn, 1860

B

A

C

D

E

F

4.2.9 Order Camarodonta Jackson, 1912 



Comparison of the most common large toxopneustid echinoids Lytechinus

Pseudoboletia

Toxopneustes

Tripneustes

Three pore pairs in one arc forming a vertical band

Four pore pairs in one arc forming a vertical band

Three pore Pore pairs in pairs in three distinct strongly vertical series oblique arcs forming a vertical band

Primary ambulacral tubercles on each plate Series of secondary tubercles interrupted

Primary ambulacral tubercles on each plate

Primary ambulacral tubercles regularly on every second plate

Primary ambulacral tubercles irregularly distributed

Seven species are listed in the genus Lytechinus, living in tropical and subtropical America: Lytechinus callipeplus H. L. Clark, 1912. Small form; Barbados and Grenada, Cape Verde Islands. Lytechinus euerces H. L. Clark, 1912. Small form; South Carolina, Antilles, Yucatan Peninsula. Lytechinus panamensis Mortensen, 1921. Gulf of Panama, Pacific. Lytechinus pictus Verrill, 1867. Southern California, USA, to Baja California, Mexico (synonymized with L. anamesus H. L. Clark, 1912 by Zigler & Lessios 2004). Lytechinus semituberculatus Valenciennes, 1846. Galapagos Islands and opposite coast of South America. Lytechinus variegatus Lamarck, 1816. Several forms (subspecies) along the southeast coast of the USA, Caribbean, and southward to Brazil. Lytechinus williamsi Chesher, 1968. Caribbean: Florida Keys, Belize, Panama, Colombia. Literature: Chesher 1968; Serafy 1970; Hendler et al. 1986; Lessios 1995; Zigler & Lessios 2004. Phylogeny of the genus Lytechinus Zigler & Lessios 2004 It is very likely that the Pacific and Atlantic clade separated before the closure of the Isthmus of Panama. The Atlantic group includes L. variegatus and L. williamsi. The third Atlantic species, L. euerces, instead seems to be more closely related to Sphaerechinus granularis, making the genus paraphyletic.

 337

Lytechinus williamsi rarely exceeds a size of 30 mm, whereas L. variegatus reaches a test diameter of 85 mm. Young specimens may be clearly distinguished because the two species live in different habitats: L. variegatus settles in sea grass beds, on sandy bottoms, and on reef flats, L. williamsi prefers the live in coral reefs. (The Atlantic species L. callipeplus is not included in this study because no specimen was available.) On the east coast of America, the two clades divided shortly after the closure: the northern group containing L. anamesus and L. pictus. These two species are synonymous, forming merely two ecotypes: a short spined component living in the littoral (L. pictus) and a long-spined one occurring in deeper water (L. anamesus). Developmental searches revealed that they are to 90–100 % cross-fertilizable (Vaquier et al. 1977; Cameron 1984, quoted in Zigler & Lessios 2004). The southern clade contains L. panamensis and L. semituberculatus, being separated from the northern one by a distance of about 3,500 km. Lytechinus panamensis is very rare, occurring only in the Bay of Panama. Lytechinus semituberculatus lives around the Galapagos Islands and along the adjacent coast of Ecuador, again divided from the former by about 1,000  km. Both of them are closely related, but differ distinctly in morphology, especially in the shape of the pedicellariae: in L. panamensis, the pedicellariae are extremely prominent (as in L. williamsi). Lytechinus callipeplus H. L. Clark, 1912 (Fig. 4.231 A, B) Test: Diameter may reach 20 mm. Ambulacral plates: High. No naked areas in ambulacra or interambulacra. Peristome: Buccal notches shallow and broad. Spines: Short and thick, tapering to a blunt tip; secondary spines short and pointed. Color: This species differs from the other small-sized species by the reddish blotches forming a ring aborally and around the ambitus. Distribution: The species is known from the waters around Grenada and Barbados, Lesser Antilles, at depths of 22 to 500  m. Chesher (1968) reported it also from the Cape Verde Islands. Lytechinus euerces H. L. Clark, 1912 (Fig 4.231 D, E) Main characteristics of the genus. Test: Diameter may reach 42 mm.

◂ Fig. 4.230: (A–C) Gymnechinus epistichus. (A) Two specimens with spines, aboral side; diameter of right sample 28 mm; Queensland,

Australia. ZMUC. (B) Oral side with spines, diameter 28 mm. The membrane is totally naked, the plates being small. (C) Three denuded tests, aboral sides, largest specimen 25 mm in diameter; Queensland, Australia. ZMUC. The variation in color is very large. (D) Gymnechinus pulchellus. Aboral side with spines, test diameter ca. 16 mm, height 6 mm; Gulf of Thailand. ZMH. The primary spines are purplish with a white tip, the secondaries entirely whitish. (E, F) Gymnechinus robillardi. Aboral side of test, diameter 29 mm; Mauritius. ZMUC. (F) Aboral side with spines, diameter 29 mm; Mauritius. ZMUC.

338 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

C

D

Fig. 4.231: (A, B) Lytechinus callipeplus. (A) Aboral side of test, diameter 8 mm; Barbados, West Indies. ZMUC. (B) Oral side: the buccal notches are small but distinct. (C, D) Lytechinus euerces. (D) Aboral side of test, diameter of test 11 mm; St. Vincent, West Indies. ZMUC. The tubercles are small and sparsely distributed. (D) Oral side: the peristomial membrane is strongly plated.

Apical system: Not flat but slightly elevated; periproct with eccentric anal opening. Interambulacra: Primary tubercles on every plate, secondary tuberculation scattered irregularly over the test, no naked areas in ambulacra nor interambulacra. Color: Test and spines whitish with some light green adapically. Distribution: From South Carolina, USA, southward through the Antilles to Trinidad, off St. Petersburg,

Florida, and along the Yucatan Peninsula to Honduras, at depths of 55 to 777 m. Biology: In the Caribbean, the species L. callipeplus and L. euerces live sympatric in the same environments (Chesher 1968). Lytechinus panamensis Mortensen, 1921 (Fig. 4.232 A) Main characteristics of the genus. Diameter may reach 30 mm, usually not more than 20 mm.

4.2.9 Order Camarodonta Jackson, 1912 



B

A

C

 339

E

D

Fig. 4.232: (A) Lytechinus panamensis. Aboral side, partly with spines, diameter of test 30 mm; Gulf of Panama, Pacific. ZMUC ECH 566. The brown color of the typical conspicuous blister-like glands of the pedicellariae faded out in alcohol. (B–E) Lytechinus pictus. (B) Aboral side with green spines, diameter of test 37 mm; Corona del Mar, California, USA. ZMUC. (C) Side view with reddish spines, diameter 40 mm; California, USA. The naked median zones are more or less developed. (D) Aboral side of test, diameter 27 mm; California, USA. Concentric and radial lines are scattered over the surface. (E) Oral side of test: the peristomial membrane is densely set with platelets.

340 

 4.2 Subclass Euechinoidea Bronn, 1860

Apical system: Rather bare, ocular plate I sometimes insert, anal opening eccentric. Ambulacra: Distinct naked areas aborally, primary tubercles almost as large as in interambulacra. Interambulacra: Aboral naked areas conspicuous. Spines: Of uniform length in ambulacra and interambulacra. Globiferous pedicellariae: Prominent, with brownish blisterlike poison glands, not purplish as in Lytechinus williamsi. Color: The spines are light greenish or purplish or almost entirely white, in young specimens banded. The denuded test is uniformly brownish or olive, the naked areas being lighter or darker, creating a radiating pattern; apical system very conspicuously whitish. Distribution: The species is endemic to the Gulf of Panama. Bathymetric range 5 to 10 m. Remark: According to Lessios (2005), this species is very rare. Lytechinus pictus Verrill, 1867 (synonym Lytechinus anamesus H. L. Clark, 1912) (Fig. 4.232 B–E) Test: Solid, low hemispherical, diameter may reach 40 mm. Ambulacra: With steep arcs of pore pairs, forming a vertical band; secondary tubercles much smaller than the primaries, and largest around the ambitus. Interambulacra: Two series of primary tubercles, secondaries much smaller, rudimentary on the aboral side, leaving a more or less naked median zone. Peristome: Slightly depressed; buccal membrane densely plated. Spines: Short and tapering to a blunt end. Color: The test is very variable, whitish with radiating and/or concentric patterns in dark green, purplish brown or purplish with whitish spots, sometimes mottled. The spines in life are bright purplish, more or less banded. Distribution: This species is restricted to the west coast of America from southern California, USA, to Baja California and the Sea of Cortez, Mexico. It lives at depths of 5 to 200 m. Lytechinus semituberculatus L. Agassiz & Desor, 1846 (Fig. 4.233) Test: Regularly hemispherical or subconical, oral side flattened, slightly sunken toward the peristome; maximum diameter about 55 mm. Apical system: Hemicyclic, very slightly eccentric; madreporite distinctly enlarged and inflated; plates densely tuberculated; gonopores large and at the distal edge of the genital plates. Ambulacra: Regular series of primary tubercles, parallel row of irregularly sized secondaries reach only a little above the ambitus; median area naked on aboral side; pore pairs in low arcs of three forming a broad band.

Interambulacra: Regular series of primary tubercles in the middle of the plate, irregular row of secondaries on outer side almost up to the apical disc, on inner side reaching just above the ambitus; median space bare. All naked areas densely covered by globiferous pedicellariae with blister-like poison glands. Peristome: Buccal membrane plated, notches large and deep. Spines: Of uniform length, hardly reaching one third of test diameter, tapering to a simple point. Color: In living specimens, the test is brownish with green spines. The well-cleaned test is green, the naked areas darker. The spines are purplish or green. Distribution: The species is restricted to the Galapagos Islands, the opposite coast of South America, and to Clarion Island; littoral zone. Lytechinus variegatus Lamarck, 1816 (Fig. 4.234) Test: Lowly hemispherical, oral side flattened; circumference round or slightly pentagonal; diameter of test up to 85 mm. Apical system: Madreporite enlarged, ocular plates I and V insert; periproct and anal opening eccentric. Ambulacra: 3 pore pairs per plate, forming a regular band; two regular series of primary tubercles, one on each plate, secondaries of same size in short, irregularly interrupted rows, median space distinctly naked on the upper side. Interambulacra: two regular series of primary tubercles, secondaries of same size, from the ambitus down to the peristome forming one horizontal row per plate, less regular and decreasing in number on the aboral side; conspicuous naked median area aborally. Peristome: More or less depressed; membrane densely plated; buccal notches deep and rounded. Spines: Slender, tapering to the pointed tip. Color: The species is very variable (name!). Three main varieties are distinguished: Lytechinus variegatus variegatus (Lamarck, 1816): The typical West Indian form is greenish, more or less with white, forming radial or zigzag patterns, sometimes wholly white. The plated buccal membrane is green as well. The greenish spines are often purplish distally. Lytechinus variegatus carolinus A. Agassiz, 1863: This subspecies is known from North Carolina to Florida, the spines are more solid and reddish, the test more or less uniformly red brown or purplish, the buccal membrane of same color. Lytechinus variegatus pallidus H. L. Clark, 1925: A paler gray purplish form is reported from the Cape Verde Islands, the aboral side being more greenish with light violet spines.

4.2.9 Order Camarodonta Jackson, 1912 



A

 341

B

C

D

Fig. 4.233: Lytechinus semituberculatus. (A) Aboral side of test, diameter 49 mm; Espanola, Galapagos Islands. ZMUC. (B) Side view of test: aborally, the naked areas in ambulacra and interambulacra are distinctly bare. (C) Oral side: the buccal notches are deeply indented being nearly parallel-sided. (D) Aboral side with spines, diameter 51 mm; Galapagos Islands. ZMUC.

Biology: The naked median zones are densely set with large globiferous pedicellariae, whitish or pinkish; distally equipped with poison blades. This species prefers shallow, quiet water, especially turtle grass beds, it is found also on rocky or sandy bottoms. Distribution: The species is known from North Carolina, USA, throughout the whole Caribbean region to southern Brazil, at Bermuda and the Cape Verde Islands. It seems it does not settle on the other Atlantic islands. Lytechinus variegatus lives from the tide zone to a depth of 250 m. Remarks: Lytechinus variegatus is distinguished from Tripneustes ventricosus by its much brighter color and the band of pore pairs in the ambulacra. In T. ventricosus, the pore pairs form three distinct vertical series.

Lytechinus williamsi Chesher, 1968 (Fig. 4.235) Test: Aborally slightly domed, oral side flattened, rounded ambitus; diameter hardly exceeds 30 mm. Apical system: Each genital plate with a large primary tubercle; all ocular plates exsert, covered by several small tubercles; madreporite hardly enlarged. Ambulacra: Regular series of primary tubercles just medial of the pore pairs from the peristome to the apical disc; secondary tubercles small leaving a naked median space aborally; 3 pore pairs per plate forming a broad band. Interambulacra: Plates relatively high, resulting in not more than 14 plates per column (as opposed to about 18–20 in L. variegatus); regular series of primary tubercles, row of secondary tubercles along the outer edge of the

342 

 4.2 Subclass Euechinoidea Bronn, 1860

A

C

B

E

D

Fig. 4.234: Lytechinus variegatus. (A) Aboral side of test, diameter 80 mm; Dominican Republic. Only the interambulacral primary tubercles form regular series, the rows in the ambulacra are interrupted. (B) Oral side of test. (C) Aboral side with spines, diameter of test 58 mm; Florida, USA. Typical green variation with broad naked areas. (D) Side view of the red carolinus form, diameter of test 51 mm; Cuba. (E) Aboral side of red carolinus form with spines, diameter of test 58 mm; Cuba.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

C

 343

plates, disappearing above the ambitus; naked median area aborally. Globiferous pedicellariae: With conspicuous purplish poison glands. Peristome: Membrane heavily plated except directly along the outer edge; buccal notches conspicuous. Spines: Primaries sharply pointed, about 40–50 % of diameter of test; number of wedges about 12; milled ring poorly developed. Color: The primary spines show a deep green, rarely they may be white. The test is beige with a purplish brown stripe along the median lines. The well-cleaned test is mottled in green gray. The large blister-like globiferous pedicellariae may be white or purplish. Biology: This species lives on the top of live coral reefs, often associated with the leaf coral Agaricia agaricites or on Acropora. Distribution: Lytechinus williamsi is reported from the Florida Keys, from Belize, Panama, and Colombia. Depth range 5 to 92 m. Remark: This species differs from Lytechinus callipeplus and L. euerces by the distinctly naked areas aborally. In L. williamsi, the interambulacral primary spines are longer than those on the ambulacra. In the other species, the aboral secondary tubercles are scattered irregularly over the aboral surface, not much smaller than the primary tubercles. Lytechinus williamsi differs from (young) L. variegatus by the appearance of the primary spines: in the former there are about 12 distinct wedges; in the latter, about 24 wedges giving the spine a rather smooth feeling. Genus Nudechinus H. L. Clark, 1912 The species vary to a great extent in the number of periproctal plates, the number of ocular plates being insert and especially in the color of test and spines. Test: Small, hemispherical, flattened on oral side. Apical system: Usually hemicyclic, ocular plates I and V being insert; periproct central or subcentral, covered by a few large plates; madreporite enlarged. Fig. 4.235: Lytechinus williamsi. (A) Aboral side with spines, diameter 34 mm; San Blas Island, Panama, Caribbean. There are purple lines along the median sutures of ambulacra and interambulacra. (B) Oral side. (C) Two other color morphs, aboral side with green and white spines from Panama (©S. Coppard 2010). The globiferous pedicellariae are set with blister-like venomous glands.

344 

 4.2 Subclass Euechinoidea Bronn, 1860

Ambulacra: 3 pore pairs per plate, the oblique arcs forming a single vertical band. Interambulacra: Plates with a central primary tubercle and a series of secondary tubercles on either side. Peristome: Distinct buccal notches, membrane usually naked. Spines: Primary spines stout with a blunt or slightly inflated tip, secondaries shorter. The genus consists of nine species, which resemble each other very much, especially in the naked tests: Nudechinus ambonensis Mortensen, 1942. West Pacific. Nudechinus darnleyensis Tenison-Woods, 1878. Australia. Nudechinus gravieri Koehler, 1905. Gulf of Aden, Djibuti, and Western Australia (discontinuous). Nudechinus inconspicuus Mortensen, 1904. Western Pacific. Nudechinus multicolor Yoshiwara, 1898. Japan and northeast Australia shallow water. Nudechinus rubripunctatus H. L. Clark, 1925. Amirante Island, Seychelles, 45 to 145 m. Nudechinus scotiopremnus H. L. Clark, 1912. Red Sea and Western Australia (discontinuous), littoral. Nudechinus stictus H. L. Clark, 1912. Sulu Archipelago, 13 to 20 m. Nudechinus verruculatus Lütken, 1864 The genus Nudechinus is distinguished from Gymnechinus by the arrangement of the apical plates. In Nudechinus, usually, the ocular plates I and V are insert and the anal opening lies more or less centrally. In contrast, in Gymnechinus, the ocular plates I and II are insert and the periproct is strongly eccentric. Literature: Rowe & Gates 1995. Nudechinus ambonensis Mortensen, 1942 (Fig. 4.236 A–C) Main characteristics of the genus. Test: Diameter does not exceed 14 mm. In some specimens, small platelets may occur on the peristomial membrane. Color: Mottled in green or brownish, spines usually banded. Distribution: Kei Islands, Amboina, Indonesia, probably throughout the entire Malayan region, littoral to a depth of 50 m. Nudechinus darnleyensis Tenison-Woods, 1878 (Fig. 4.236 D–F) Main characteristics of the genus. Maximum diameter 29 mm. Ambulacral and interambulacral plates: On the oral side densely tuberculated, aborally showing distinct naked median areas.

Peristome: Membrane totally naked except of buccal plates. Color: Radiating stripes in greenish or brownish, spines not banded. Distribution: Endemic to northern Australia from Shark Bay in the West to Brisbane on the east coast. Bathymetric range: littoral to a depth of 36 m. Nudechinus gravieri Koehler, 1905 (Fig. 4.237 A) Characteristics of the genus. Test: Small forms with a maximum test diameter of 13 mm. Very much like Nudechinus scotiopremnus in having the mottled green spots aborally. In both species, the spines may be banded or not, but only in N. gravieri they can be rosy. Mortensen cited further some differences in the shape of the tridentate pedicellariae. Distribution: Gulf of Aden and Western Australia from Broome to Bunbury (discontinuous like Nudechinus scotiopremnus). Depth 9 to 12 m. Nudechinus inconspicuus Mortensen, 1904 (Fig. 4.237 B) Characteristics of the genus. Test: Maximum diameter 10 mm. The spines are purplish at the base, whitish distally. The test has radial stripes in brownish or purplish. Distribution: Probably widely distributed in the central Pacific, littoral zone. Nudechinus multicolor Yoshiwara, 1898 Characteristics of the genus. Test: Diameter may reach 17 mm. Ambulacra: Primary tubercles much larger than secondaries, rather regular series of small tubercles perradially within the pore zones, more irregularly in the interporiferous zone. Interambulacra: Primary tubercles subcentrally, much smaller secondaries irregularly distributed. All plates with very small militaries giving the surface a rough appearance. Color: The test is greenish with lighter radiating stripes in the ambulacra; ambitally, there are one or two dark greenish to brownish spots in the midline of both areas. The spines are whitish with two or three narrow bands of violet, the base being white. Distribution: Japan, at shallow water, North East Australia (Rowe & Gates 1995). Nudechinus rubripunctatus H. L. Clark, 1925 This species seems to be distinguished from all other species of Nudechinus in having red spots on its test.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

D

 345

C

E

Fig. 4.236: (A–C) Nudechinus ambonensis. (A) Aboral side of test, diameter 6 mm; Kei Islands, Indonesia. ZMUC. Oral side of test. (C) Oral side with spines, diameter of test 5.5 mm; Kei Islands. (D, E) Nudechinus darnleyensis. (D) Aboral side of test, diameter 19 mm; Bowen, Queensland, Australia. ZMUC. The median areas of the ambulacra and interambulacra are naked. (E) Aboral side with spines, diameter 25 mm; East Australia. ZMUC.

Further, Clark (1925) mentioned that one of the buccal plates is larger than the other. Occurrence: Amirante Island, Seychelles, 45 to 145 m. Nudechinus scotiopremnus H. L. Clark, 1912 (Fig. 4.237 C, D) Test: Regularly hemispherical, rarely subpentagonal; diameter of test may reach 25 mm. Apical system: Ocular plates I and V broadly insert, madreporite slightly enlarged and inflated; periproct and anal opening subcentral. Ambulacra: Two regular series of primary spines, conspicuous rows of slightly smaller secondaries; pore pairs in oblique rows of three, forming a vertical band.

Interambulacra: Regular series of primary tubercles approximately in the middle of the plates, rows of secondaries on both sides, densely distributed small miliary tubercles. Peristome: Distinctly sunken; peristomial membrane naked except for the small buccal plates; notches sharply indented, but not deep. Spines: robust, tapering to a blunt tip, about 3 mm long, a little longer in west Australian populations. Color: The primary spines are whitish with green bases, sometimes banded. The bare test has more or less conspicuous dark green spots in a radial or concentric pattern or it may be uniformly green.

346 

A

C

 4.2 Subclass Euechinoidea Bronn, 1860

B

D

Fig. 4.237: (A) Nudechinus gravieri. Aboral side, partly with spines, diameter 12 mm; Broome, Western Australia. ZMUC. (B) Nudechinus inconspicuus. Two tests with spines, diameter 8 and 9 mm; Fiji Islands. ZMH. There are radiating patterns. (C, D) Nudechinus scotiopremnus. Oral side of test, diameter 18 mm; Gulf of Suez, Egypt, Red Sea. The thick buccal membrane is naked except for the ten small buccal plates. (D) Side view with spines, diameter 21 mm; Hurghada, Egypt, Red Sea.

Distribution: Nudechinus scotiopremnus is known from the Red Sea, including the Bitter Lakes, and in western Australia from Broome to Shark Bay. It lives in the littoral zone to a depth of 10 m. Nudechinus stictus H. L. Clark, 1912 Characteristic of the genus. Test: Maximum recorded test diameter 8 mm. Apical system: Seems to be dicyclic. Ambulacra: Primary tubercles much larger than secondaries, which are restricted to the narrow interporiferous zone. Interambulacra: Regular rows of primary tubercles, secondaries much smaller and scarcely scattered. Color: The test is whitish, usually with a very conspicuous purple spot in the median zone of both

areas and a some smaller spots encircling the apical system. The spines are mainly white with rose violet or purplish. Distribution: The species is known from the Sulu Archipelago at a depth of 13 to 20 m. Nudechinus verruculatus Lütken, 1864 (synonym Cyrtechinus verruculatus Lütken, 1864) (Fig. 4.238) In shape and structure of the test and in the colors, this species is almost identical to Nudechinus scotiopremnus, and both of them are very variable. The only reliable difference is that the buccal membrane is plated in Nudechinus verruculatus and naked in N. scotiopremnus. Denuded tests without buccal membrane are often indistinguishable.

4.2.9 Order Camarodonta Jackson, 1912 



A

C

 347

B

D

Fig. 4.238: Nudechinus verruculatus. Aboral side of four tests, diameter of largest specimen 22 mm. The tests show radial and concentric patterns in greenish colors. (B) Oral side of test, diameter 19 mm. (C) Side view of test, diameter 21 mm. (D) Oral side with spines, diameter of test 22 mm. The peristomial membrane is densely set with small plates. All specimens found at Ile de la Réunion.

Distribution: This species is known all over the tropical region of the Indian Ocean and the Pacific islands. It lives mainly in the littoral zone, but is also found to a depth of 130 m. Remarks: The different geographical distributions of N. scotiopremnus, which is restricted to the Red Sea and Western Australia, may be a reliable distinction between the two species. Genus Pseudoboletia Troschel, 1869 Test: Large, in profile, low hemispherical to subconical, oral side flat. Apical system: Hemicyclic, anal opening subcentral; madreporite enlarged.

Ambulacra: Arcs of 4 to 5 pore pairs to each compound plate; one primary tubercle per plate. Ambulacra and interambulacra: With equal-sized primaries and secondaries around ambitus, and on oral side, forming uniform horizontal series; on aboral side, with rather naked median zones. Peristome: Buccal notches deep, buccal membrane plated. Four species are known, two in the Atlantic and two in the Indo-Pacific: Pseudoboletia atlantica H. L. Clark, 1912, Endemic to Ascension and St. Helena in the southern Atlantic. Pseudoboletia indiana Michelin, 1862. Indo-Pacific.

348 

 4.2 Subclass Euechinoidea Bronn, 1860

Pseudoboletia maculata Troschel, 1869. Indo-West Pacific. Pseudoboletia occidentalis H. L. Clark, 1921. West Indies. Remarks: Pseudoboletia differs from Tripneustes by the number of pore pairs per plate, the former has four in arcs, the latter has three in distinct vertical series. Toxopneustes pileolus also has 3 pore pairs in an arc, but in that species, the color of the test is dark with light patterns, whereas in Pseudoboletia, it is light with a dark pattern. Literature: Clark & Rowe 1971; Guille et  al. 1986; Shigei 1986; Hendler et al. 1995; Rowe & Gates 1995; Miskelly 2002. Pseudoboletia atlantica H. L. Clark, 1912 (Fig. 4.239 A, B) Main characteristics of the genus. Test: Maximum diameter is 112 mm.

A

C

Apical system: Ocular and genital plates with sparse tubercles, remaining space with numerous miliaries set with pedicellariae. Ambulacra: Usually arcs of 5 pore pairs, but often 4 pore pairs per plate. Interambulacra: On the oral side, up to 7 tubercles in a horizontal series. Naked spaces in ambulacra and interambulacra densely set with small miliary tubercles set with numerous pedicellariae. Peristome: Very deeply indented buccal notches. Color: The spines may be whitish, the base being green or brown or with bands in dull green or brown. The test is a creamy white with radial darker bands in pink or brown olive. Sometimes, there are darker spots or bands on aboral

B

D

E

Fig. 4.239: (A, B) Pseudoboletia atlantica. (A) Oral side of test, diameter 75 mm; St. Helena. (B) Aboral side with spines, diameter 93 mm; St. Helena. (C–E) Pseudobolatia indiana. (C) Aboral side of test, diameter 62 mm; New South Wales, Australia. There are no dark spots as in Pseudoboletia maculata, but the arrangement of the tubercles is identical. (D) Oral side of test. (E) Aboral side with spines, diameter 81 mm; New South Wales, Australia. The spines are whitish with a faint purplish tip.

4.2.9 Order Camarodonta Jackson, 1912 



A

 349

B

C

Fig. 4.240: (A–C) Pseudoboletia maculata. (A) Aboral side of test, diameter 73 mm; Negros, Philippines. The dark patches form irregular, concentric rings. (B) Close-up of aboral side. (C) Underwater: oblique view with spines, Bohol, Philippines. The dark spots of the spines correspond with the patches on the test surface (photo by H. Moosleitner).

median spaces arranged more or less in concentric circles. The apical plates show usually a darker distal edge. Distribution: The species is only recorded from Ascension and St. Helena in the South Atlantic. Pseudoboletia indiana Michelin, 1862 (Fig. 4.239 C–E) The structure of the test in Pseudoboletia indiana is virtually identical to P. maculata. They differ only in color and pattern, the latter showing darker spots, the former not. The spines of P. indiana are white, sometimes with a purplish tip. Shigei (1986), however, synonymized P. indiana and P. maculata because he found it impossible to separate spotted and more uniformly colored specimens, since all intermediates occur. Distribution: This species is known from Madagascar and Mauritius to Hawaii and the South Pacific Islands and from central Japan (Sagami Bay) to Australia and New Caledonia. It lives from the littoral zone to a depth of 100 m. Pseudoboletia maculata Troschel, 1869 (Fig. 4.228 B, 4.240) Test: Maximum diameter 95 mm. Apical system: Hemicyclic; plates covered with tubercles of different size.

Ambulacra: Pore pairs in arcs of 4, rarely 5, the two lowermost one above the other, the two upper ones oblique, in the whole forming a densely perforated band; crowded in a small phyllode at the very edge of the peristome; regular vertical series of tubercles in the pore zones; small miliary tubercles scattered over the remainder of the plate. Interambulacra: Secondary tubercles almost as large as primaries, forming regular horizontal series; numerous small miliary tubercles; naked median areas adapically. Peristome: Sunken; buccal membrane with plates, covered by many spines and pedicellariae; notches very deep and sharp. Spines: Short and simple aborally with blunt ends, the oral spines are longer and flattened with a widened tip. Color: The spines of an individual are of different color: some are dark brownish, lighter at the distal end, others are yellowish green becoming brown distally or whitish with pinkish ends. The dark spines correspond to the spots on the test surface. The bare test is grayish to whitish, usually with darker grayish or brownish patches in ambulacra and interambulacra on the upper side, more or less forming concentric and/or radial patterns. Distribution: Pseudoboletia maculata is found in the IndoWest Pacific, from Ceylon to the Malayan Archipelago and

350 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C

D

Fig. 4.241: Sphaerechinus granularis. (A) Aboral side of test, diameter 71 mm; Greece. The test is purplish, only the pore zones are a little lighter. (B) Oral side. There are distinct buccal notches. (C) Close-up of ambulacrum and adjacent interambulacra: the primary tubercles form two regular vertical series, the secondaries are equal-sized. The pore pairs in the ambulacra are arranged in arcs of four or five. Scale: 10 mm. (D) Underwater: the spines are dark purple with white tips. Turkey (photo by M. Moosleitner).

from the Macclesfield Bank to Australia. It lives at depths between 10 and 100 m. Pseudoboletia occidentalis H. L. Clark, 1921 Ambulacra: 4 pore pairs per arc. Color: The species shows the same dark patches as Pseudoboletia maculata. Distribution: Known from the Lesser Antilles and Tobago, perhaps at a depth of 50 to 150 m. Genus Sphaerechinus Desor, 1856 The monospecific genus is characterized by 4–6 pore pairs to a plate and very pronounced buccal notches.

Sphaerechinus granularis Lamarck, 1816 (Fig. 2.2 B, 4.241) Test: Very variable from low hemispherical to highly domed or subconical; diameter up to 160 mm. Apical system: Hemicyclic with ocular plates I and V insert, madreporite enlarged; periproct eccentric. Ambulacra: 5 to 6 pore pairs per plate, often 3 or 4 in a steep arc, the two others oblique and a little separated; two regular series of primary tubercles, as large as interambulacral ones, secondaries in the median space of same size as well, irregularly arranged. Interambulacra: Two regular series of primary tubercles, secondaries on either side of same size, forming a regular horizontal row on each plate and vertical series in the column.



There are no naked areas in ambulacra or interambulacra. Peristome: Often pentagonal; buccal notches rounded, distinct, but not very deep; few plates on the buccal membrane. Spines: Short and stout, with blunt tips. Color: The spines are more or less dark purplish with white tips or white with purplish bases. The bare test is lighter purplish with darker or lighter pore zones creating a radial pattern. Biology: Sphaerechinus granularis often holds shell fragments or algae over its aboral side for camouflage and against direct light. Sometimes, it resembles a clump of shells and debris. Juvenile and adult specimens live in separated populations in different habitats (Ernst 1973). Distribution: This species is known from the Mediterranean to the Azores, the Canaries, and Cape Verde Islands, and from the Gulf of Guinea, West Africa, to the Channel Islands. It is likely that it has expanded northward to Denmark. The animals live from the littoral zone to a depth of 100 m. Remarks: Sphaerechinus granularis differs from Paracentrotus lividus by the color of its spines, which are purplish with at least a white tip. In P. lividus, they are uniformly greenish or dark purplish. The denuded test is purplish in the former and green in the latter. From Echinus esculentus, it is distinguished by its more dense spination and tuberculation. In that species, 3 pore pairs are found in an arc, contrasting to Sphaerechinus granularis with 4 to 6 pore pairs. Literature: Ernst 1973. Genus Toxopneustes L. Agassiz, 1841 The species of Toxopneustes are large forms having 3 pore pairs to an ambulacral plate. They are characterized by large, very conspicuous globiferous pedicellariae, which have a flower-like appearance (see Fig. 4.244). Test: Low hemispherical or subconical, oral side flattened, peristomial edge slightly sunken. Apical system: Hemicyclic with ocular plates I and V broadly insert, periproct eccentric, anal opening close to ocular plate I; madreporite strongly enlarged. Ambulacra: Pore pairs in oblique arcs of three per compound plate forming a broad band of almost uniform width; primary tubercle to every second plate, several secondaries irregularly distributed. Interambulacra: Multiple tubercles of equal size. On the aboral side, all tubercles are smaller than on the oral side. Peristome: Long, deeply indented buccal notches. Spines: Rather short.

4.2.9 Order Camarodonta Jackson, 1912 

 351

Remark: Toxopneustes differs from Tripneustes in having the pore pairs in a nearly uniform, broad band. In Tripneustes, in contrast, there are three distinct vertical series of pore pairs being separated by small tubercles. In this latter genus, the tuberculation is much sparser lacking multiple tubercles of subequal size. Four species are known, distributed in the IndoPacific from East Africa to the west coast of America: Toxopneustes elegans Döderlein, 1885. Restricted to Japan. Toxopneustes maculatus Lamarck, 1816. Only found at the Christmas Islands. Toxopneustes pileolus Lamarck, 1816. Very common in the whole Indo-West Pacific. Toxopneustes roseus A. Agassiz, 1863. Confined to the tropical west coast of America. Literature: Guille et al. 1986; Shigei 1986; Rowe & Gates 1995; Miskelly 2002. Toxopneustes elegans Döderlein, 1885 (Fig. 4.242 A–C) Test: Hemispherical, distinctly sunken toward the peristome; maximum diameter 75 mm. Apical system: One large tubercle per plate. Ambulacra: Primary tubercles as large as interambulacral ones and set on every second plate; forming an irregular row with secondaries; pore pairs in low arcs, tending to form three vertical rows. Interambulacra: Primary and secondary tubercles of same size, forming a horizontal row. Peristome: Relatively large, buccal notches deep; buccal plates regularly encircling the mouth; membrane with some scattered small platelets. Spines: Short and somewhat club-shaped, with blunt end. Color: The aboral spines are yellowish green with a clear, purplish black ring not far from the point. The oral spines are white, distally ringed. The bare test is light purple to gray pink. There are no irregular, concentric bands on the aboral side. Distribution: Found in Japanese waters from Sagami Bay to southern Kyushu, at 2 to 20-m depth. Toxopneustes maculatus Lamarck, 1816 (Fig. 4.242 D) Characteristics of the genus. Test: Maximum diameter 100 mm. Oral side flat, not sunken toward the peristome. Color: The test has a broad purplish band aborally and a narrow irregular around the ambital oral side. There may be considerable variation up to an entirely purplish aboral side. Distribution: Reported only from the Palmyra and Christmas Islands, central Pacific, in the littoral.

352 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

D

C

Fig. 4.242: Toxopneustes elegans. (A) Aboral side of test, diameter 65 mm; Kagoshima; Kyushu, Japan. ZMUC. The plates in ambulacra, and interambulacra are densely tuberculated, leaving a narrow, naked area along the median zone. (B) Close-up of aboral side; scale 10 mm. (C) Aboral side with spines, diameter 83 mm; Kagoshima, Kyushu, Japan. ZMUC. The spines have a distal dark ring. (D) Toxopneustes maculatus. Aboral side of test, diameter 73 mm; Palmyra Island. ZMUC.

Toxopneustes pileolus Lamarck, 1816 (Fig. 4.228 A, 4.243, 4.244) Test: Low hemispherical, oral side flattened; circumference round to rounded pentagonal; maximum diameter up to 135 mm. Apical system: Madreporite much larger than other genital plates and almost naked; ocular plates I and V insert; periproct eccentric. Ambulacra: Interporiferous zone broad; primary tubercles of same size as interambulacral ones, on every second (or third) plate, sometimes irregular; median

space covered with irregularly arranged secondaries of same size and numerous small ones; narrow, but distinct naked median line; 3 pore pairs per plate in strongly oblique arcs, thus forming a broad band of three vertical series. Interambulacra: Two series of primary tubercles, secondaries of same size on either side, numerous small miliary tubercles; median zones naked. Peristome: More or less sunken; very elongated, narrow, sharply indented buccal notches; membrane with small, scattered plates, set with small pedicellariae.



Spines: Short, on the aboral side 6–8  mm, orally 10–12 mm in length. Color: The spines are banded in purplish, greenish, whitish, or reddish hues. The bare test shows more or less distinct radial stripes in brownish, greenish, or purplish with very characteristic irregular bands or spots arranged concentrically. Sometimes, these spots may be inconspicuous or even missing completely. The periproctal plates in the apical system are white. Biology: In life, the test is densely covered by large globiferous pedicellariae visible to the naked eye. The widely open valves, connected by a fine skin, look like little flowers with a purplish center. They are equipped with glands containing a strong poison. Scattered between them there are larger pedicellariae with even more solid pincers, also with poison glands. The valves end in a sharp hook, which may penetrate human skin, causing very painful stings. Several stings can result temporary paralysis. Distribution: Toxopneustes pileolus is found from East Africa to the Fiji Islands and New Caledonia and from central Japan to Australia. It lives from the littoral zone to a depth of about 90 m. Remarks: This species differs from Pseudoboletia maculata in having 3 pore pairs, the latter having 4 pore pairs per plate. From Tripneustes gratilla, it is distinguished by its much more dense tuberculation and by its color. In T. gratilla, the test is light purple or rose with more or less broad, white radial sections. Toxopneustes roseus A. Agassiz, 1863 (Fig. 4.244 D–F) Test: Lowly conical, diameter generally up to 100  mm, exceptionally to 130 mm. Apical system: Hemicyclic. Ambulacra: Conspicuous naked median zones, tubercles smaller than in Toxopneustes pileolus. Interambulacra: Median areas distinctly naked and usually sunken; tubercles smaller than in T. pileolus. Globiferous pedicellariae: With purplish, conspicuously leaf-shaped centers. Color: In life specimens, the test is light purple with light green brown or rose spines, tipped with white, the blossom-like, round pedicellariae are whitish with a dark red purple center. The bare test is greenish or grayish, the median zones with a light purplish or rosy tinge. Distribution: Toxopneustes roseus is known along the tropical west coast of America from the Gulf of California to Panama and Columbia from 2 to 50 m. Remarks: This species differs from Toxopneustes pileolus by its lack of concentric spots and its distinct radial stripes. From Tripneustes depressus, it is distinguished by the flower-like pedicellariae and by the band of pore pairs; the latter has three distant vertical series.

4.2.9 Order Camarodonta Jackson, 1912 

 353

Genus Tripneustes L. Agassiz, 1841 The species of Tripneustes are large forms, very common in the tropical regions of the Indo-Pacific and the Atlantic. They are characterized by broad pore zones with three well separated vertical series of pore pairs. Test: More or less high hemispherical or subconical; oral side flat; outline round or rounded pentagonal. Apical system: Hemicyclic, madreporite enlarged; periproct subcentral. Ambulacra: Broad; 3 pore pairs per compound plate forming three vertical series throughout being separated by more or less regular rows of tubercles; juveniles have still simple arcs of 3 pore pairs; only every third or fourth plate set with a primary tubercle. Interambulacra: Primary tubercles small, mostly on each plate, but not always; secondaries sparse and irregular; oral side set with dense horizontal series of subequal tubercles. Peristome: Buccal notches deep and sharp. Spines: Short. Pedicellariae: The naked aboral areas are more or less densely covered by small globiferous pedicellariae. Three species are known, living in different geographical regions: Tripneustes depressus A. Agassiz, 1863. Tropical west coast of America. Tripneustes gratilla Linné, 1758. Indo-West Pacific. Tripneustes ventricosus Lamarck, 1816. Caribbean, Brazil, and West Africa. Lessios et  al. (2003) have shown that the two Pacific species, T. gratilla and T. depressus are in fact genetically the same species. The Eastern Pacific Barrier, 5,000 km of deep water, is obviously relatively unimportant for this genus, in contrast to Eucidaris, Diadema, and other genera. Literature: Serafy 1979; Dafni 1983; Guille et  al. 1986; Shigei 1986; Rocue & Gates 1995; Hendler et  al. 1995; Miskelly 2002; Lessios et al. 2003; Zigler & Lessios 2003; Lessios 2005. Tripneustes depressus A. Agassiz, 1863 (Fig. 4.245 A, B) This species, genetically related to Tripneustes gratilla, resembles also Tripneustes ventricosus. It is distinguished by its more densely plated buccal membrane and by its color. The arrangement of the tubercles and pore pairs is similar in the two species. Distribution: This species is known along the west coast of America from the Gulf of California to the Galapagos Islands. Tripneustes gratilla Linné, 1758 (Fig. 4.245 C, 4.246) Test: Hemispherical, rarely subglobular, diameter up to 120 mm, exceptionally even more. Apical system: Plates with few tubercles mainly along the inner edge, periproctal plates also tuberculated.

354 

A

 4.2 Subclass Euechinoidea Bronn, 1860

B

C

E

D

Fig. 4.243: Toxopneustes pileolus. (A) Aboral side of test, diameter 69 mm; Negros, Philippines. There are radial patterns and irregular, concentric bands. (B) Oral side of test. (C) Close-up of ambulacrum: the ambulacral plates are set with three dense vertical series of pore pairs. Scale: 10 mm. (D) Aboral side with spines, diameter 83 mm; Negros, Philippines. Dried and folded pedicellariae are visible among the short spines. (E) Oral side with spines: the banded spines are longer than those of the aboral side and more intensely colored.

4.2.9 Order Camarodonta Jackson, 1912 



A

B

 355

C

D

F

E

Fig. 4.244: (A–C). Toxopneustes pileolus. Globiferous pedicellariae. (A) Valves of large and small globiferous pedicellariae: the poison tube in the hook is open along the upper edge, becoming closed only at the sharply pointed distal end. (B) Diagrammatic view of large form: three muscular cords serve for opening and closing of the valves. The skin is bordered by a white edge. Scale: (A, B) 500 μm (Mortensen 1943). (C) Pedicellariae on the test: the small globiferous pedicellariae with the conspicuous white edge are widely open or folded up. Their stalks are set with poison glands immediately below the valves. One large, closed pedicellaria is visible in the foreground. Scale: 3 mm. (D–F) Toxopneustes roseus. (D) Side view of test, diameter 125 mm; Baja California, Mexico (photo by W. Clarenbach). (E) Close-up of globiferous pedicellariae, scale 2 mm; specimen from Mazatlan, Mexico. ZMH. (F) Living specimen, Taboguilla, Panama, Pacific coast: the globiferous pedicellariae are widely open looking like blossoms (photo by S. Coppard).

356 

A

B

C

 4.2 Subclass Euechinoidea Bronn, 1860 Ambulacra: Broad pore zones, 3 pore pairs per plate, arranged in three distinct vertical series, separated by irregular series of tubercles, interporiferous zones with small primary tubercles on every third or fourth plate; few, still smaller secondaries, irregularly more or less in vertical rows, adapically disappearing, with more or less distinct naked median areas. Interambulacra: Narrower than ambulacra; two regular series of rather small primary tubercles, secondaries of same size, reduced adapically, leaving a more or less broad, naked median space; oral side much more densely tuberculated. Peristome: Small, not depressed, buccal membrane with scattered platelets; notches sharp and deep. Spines: Short and thin. Color: Very variable: the primary spines may be orange, purplish, or whitish, the secondaries are white, the median spaces dark (due to numerous almost black pedicellariae), more or less distinctly limited. The bare test is white, the median zones in ambulacra and interambulacra are more or less intensely rose violet, sometimes the whole test is violet with lighter pore zones. Distribution: The species is one of the most common sea urchins in the Indo-Pacific, known in East Africa from the Red Sea to Natal, from central Japan to Australia and from the Norfolk Islands to Hawaii. It lives from the littoral zone to a depth of 75 m. Remarks: With its dark, naked median zones, Tripneustes gratilla resembles Mespilia globulus in life, but it is distinguished by its much scarcer spines. The bare test differs by having three distant vertical series of pore pairs and deep buccal notches. From Toxopneustes pileolus, the species is distinguished by its distinct naked areas and by the color of its test. The bare tests of Tripneustes gratilla and T. ventricosus are difficult to separate. The naked zones may be not so distinct in the latter and the tubercles may be larger, but there is much variation. In the northern Red Sea, a variety is found, Tripneustes gratilla elatensis Dafni, 1983, with sparse tuberculation Fig. 4.245: (A, B) Tripneustes depressus. Aboral side, partly with spines, diameter of test 116 mm; Socorro Island, Mexico. ZMUC. The tubercles are small. The median areas of the interambulacra and ambulacra are naked. (B) Close-up of aboral side: the pore pairs form three well separated vertical series. (C) Tripneustes gratilla. Underwater, Bohol, Philippines. This beautiful specimen is unusually white, only some dark pedicellariae are scattered in the naked median areas of ambulacra and interambulacra (photo by H. Moosleitner).

4.2.9 Order Camarodonta Jackson, 1912 



A

 357

B

C

D

Fig. 4.246: Tripneustes gratilla. (A) Aboral side with spines, diameter of test ca. 35 mm; Negros, Philippines. The primary spines along the dark naked median zones are orange. The median zones in ambulacra and interambulacra are covered with fine, black pedicellariae. (B) Aboral side of test, diameter 95 mm; Maldives. The ambulacra have broad pore zones and are wider than the interambulacra. (C) Oral side of test. (D) Close-up of upper side: the ambulacrum and the adjacent interambulacra are sparsely tuberculated. The pore pairs are arranged in three, well separated, vertical series. Scale: 5 mm.

and the entire upper surface densely covered by globiferous pedicellariae (Fig. 4.247 A). These may be light or dark purplish, and only the tips of the primary spines are visible. The test is flattened above and below with a rounded margin. Tripneustes ventricosus Lamarck, 1816 (Fig. 4.247 B–D) This species closely resembles Tripneustes gratilla. It is characterized by the following features: Test: Diameter up to 150 mm.

Ambulacra: Three vertical series of pore pairs, separated by small tubercles; naked median areas narrow. Interambulacra: Two series of primary tubercles from peristome to apical disc; series of equal-sized secondaries mainly round the ambitus; naked median areas rather indistinct or missing completely, but sometimes, they may also be present. Color: In life, the test is mostly dark brown, the spines, strongly contrasting, white or dirty whitish. The surface of

358 

 4.2 Subclass Euechinoidea Bronn, 1860

A

B

C D

Fig. 4.247: (A) Tripneustes gratilla elatensis. Underwater, Safaga, Red Sea. Enormous numbers of pedicellariae cover the test like a compact sheath, the purplish spines are hardly visible. The long podia examine the vicinity. (B–D) Tripneustes ventricosus. (B) Aboral side of test, diameter 84 mm; Florida, USA. The ambulacra are almost as broad as the interambulacra. (C) Oral side of test. (D) Aboral side with spines, diameter 83 mm; Dominican Republic. The median areas are not conspicuously limited. The spination is more uniform than in Tripneustes gratilla.

the test is set with numerous dark globiferous pedicellariae with the tips of the valves white. Sometimes, the spines and the test are entirely white (common name “white sea urchin”) The peristomial membrane is light brown with scattered olive green spots. The bare test is mainly white with more or less intensively light violet median zones. Distribution: The species is known from Florida, the Bermudas, and the West Indies to Brazil and West Africa. It lives from the littoral zone to a depth of 55 m.

Remarks: In Tripneustes ventricosus, the naked zone is not as distinct as in Tripneustes gratilla and the tubercles are larger. But the range of variation is wide, and there may be specimens, which look virtually identical. Tripneustes ventricosus differs from Lytechinus variegatus by its white spines and dark pedicellariae. The bare test is distinguished by its lack of bright colors and by having pore pairs, developed in three well separated vertical series. In L. variegatus, the pore pairs form a dense band.

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notes on other echinoids from the Bay of Plenty. Records of the Dominion Museum 82: 9–19. Baker, A. N. (1982): Echinoidea. In: Shepherd, S. A. & Thomas, I. M. (eds.): Marine Invertebrates of Southern Australia, part I. Government Printer, Adelaide: 437–454. Baker, A. N. (1998): The rediscovery of Echinus elevatus in New Zealand and a new name for Acanthotrema. Journal of the Royal Society of New Zealand 28: 281–286. Barker, M. F. (1984): Reproduction and development in Goniocidaris umbraculum, a brooding echinoid. In: Keegan, B. F. & O’Connor, B. D. S. (eds.): Proceedings of the Fifth International Echinoderm Conference 1984, Galway. Balkema, Rotterdam: 207–214. Baumeister, J. G. & Koch, I. (1998): Arbaciella elegans aus dem Tyrrhenischen Meer. Stuttgarter Beiträge zur Naturkunde Serie A (Biologie) 568: 1–6. Baumiller, T. K., Mooi, R. & Messing, C. G. (2008): Urchins in the meadow: paleobiological and evolutionary implications of cidaroid predation on crinoids. Paleobiology 34: 22–34. Bernasconi, I. (1953): Monografia de los equinoideos Argentinos. Anales del Museo de Historia Natural 6: 1–58. Bernasconi, I. (1955): Una nuevo especie de Diadematidae tropica, Centrostephanus besnardi. Neotropica 1: 92. Bernasconi, I. (1969): Equinodermos Antarcticos. Revista del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” Zoologia 9: 197–210. Biermann, C. H., Kessing, B. D. & Palumbi, S. R. (2003): Phylogeny and development of marine model species: strongylocentrotid sea urchins. Evolution and Development 5: 360–371. Boolootian, R. A., Giese, A. C., Tucker, J. S. & Farmanfaian, A. (1959): A contribution of the biology of a deep sea echinoid, Allocentrotus fragilis. Biological Bulletin 116: 362–372. Bosch, I., Beauchamps, K. A., Steele, M. E. & Pearse, J. S. (1987): Development, metamorphosis and seasonal abundance of embryos and larvae of the Antarctic sea urchin Sterechinus neumayeri. Biological Bulletin 173: 126–135. Brey, T. (1991): Population dynamics of Sterechinus antarcticus on the Weddell Sea shelf and slope, Antarctica. Antarctic Science 3: 251–256. Brey, T., Pearse, J., Basch, L., MacClintock, J. & Slattery, M. (1995): Growth and production of Sterechinus neumayeri in McMurdo Sound, Antarctica. Marine Biology 124: 279–292. Buchanan, J. B. (1966): The biology of the Echinocardium cordatum from different habitats. Journal of the Marine Biological Association of the UK 46: 97–114. Campbell, A. C. & Jensen, M. (1993): Rostrate pedicellariae: a morphologically distinct form of echinoid test appendage. Journal of Morphology 218: 237–247. Chesher, R. H. (1966): Report on the Echinoidea collected by RV Pillsbury in the Gulf of Guinea. The RV Pillsbury Deep-Sea Biological Expedition to the Gulf of Guinea 1964–65. Studies in Tropical Oceanography, Institute of Marine Sciences (University of Miami) 4: 209–232. Chesher, R. H. (1968): Lytechinus williamsi, a new urchin from Panama. Breviora 305: 1–13.

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In: Tunnell, J. W., Felder, D. L. & Earle, S. A. (eds.). Gulf of Mexico: Origin, waters and biota. Texas A&M University Press: 1177–1204. Pearse, J. S. & Bosch, I. (1994): Brooding in the Antarctic: Östergren had nearly right. In: David, B., Guille, A., Féral, J.-P. & Roux, M. (eds.). Echinoderms through time. Balkema, Rotterdam: 111–120. Pearse, J. S. & Lockhart, S. J. (2004): Reproduction in cold water: paradigm changes in the 20th century and a role for cidaroid sea urchins. Deep-Sea Research II 51: 1533–1549. Pearse, J. E. & Mooi, R. (2007): Echinoidea. In: Carlton, J. T. (ed.): Intertide Invertebrates from Central California. University of California Press: 914–922. Pearse, J. S., Mooi, R., Lockhart, S. & Brandt, A. (2008): Brooding and species diversity in the Southern Ocean: Selection for brooders or speciation within brooding clades? In: Krupnik, I., Lang, M. A. & Miller, S. E. (eds.). Smithsonian at the Poles Contributions to International Polar Year Science. Smithsonian Institution Press, Washington: 181–196. Phelan, T. F. (1970): Field guide to the cidaroid echinoids of the Northwestern Atlantic, Gulf of Mexico and the Caribbean Sea. Smithsonian Contribution to Zoology 40: 1–67. Pierrat, B., Saucède, T., Festeau, A. & David, B. (2012): Antarctic, sub-Antarctic and cold temperate echinoid database. ZooKeys 204: 47–52. Poulin, E. & Féral, J.-P. (1996): Why are there so many species of brooding Antarctic echinoids? Evolution 50: 820–830. Poulin, E., Palma, A. T. & Féral, J-P. (2002): Evolutionary versus ecological success in Antarctic benthic invertebrates. Trends in Ecology and Evolution 17: 218–222. Raff, R. A. (1987): Constraint, flexibility and phylogenetic history in the evolution of direct development in sea urchins. Developmental Biology 119: 6–19. Rowe, F. W. E. (1989): Nine deep-water species of echinodermata from Norfolk Island and Wanganella Bank with check-list. Proceedings of the Linnean Society of New South Wales 3: 257–291. Rowe, F. W. E. & Gates, J. (1995): Echinodermata. In: Wells, A. (ed.). Zoological catalogue of Australia, Vol. 33. CSIRO, Melbourne: 171–260. Rowe, F. W. E. & Hoggett, A. K. (1985): The cidarid echinoids of New South Wales (Australia). Proceedings of the Linnean Society of New South Wales 108: 225–261. Schultz, H. (2005a): Interaktionen zwischen Mollusken und Seeigeln. Club Conchylia Informationen 37: 41–48. Schultz, H. (2005b): Sea urchins. A guide to worldwide shallow water species. Heinke & Peter Schulz Partner Scientific Publications, Hemdingen. Schultz, H. (2009): Sea urchins II. Worldwide irregular deep water species. Heinke & Peter Schulz Partner Scientific Publications, Hemdingen. Schultz, H. (2011): Sea urchins III. Worldwide regular deep water species. Heinke & Peter Schulz Partner Scientific Publications, Hemdingen. Serafy, D. K. (1979): Echinoids. Memoirs of the Hourglass Cruises 5: 1–116. Shigei, M. (1970): Echinoids of the Bonin Islands. Journal of the Faculty of Science, University of Tokyo 12: 1–22. Shigei, M. (1975): A new species of the cidarid sea urchin from the East China Sea. Journal of the Faculty of Science, University of Tokyo 4: 321–328.

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Tracey, D. M., Anderson, O. F. & Naylor, J. R. (2011): A guide to common deep sea invertebrates in New Zealand waters. Echinoidea. New Zealand Aquatic Environment and Biodiversity Report 86: 262–282. Tsuchiya, M. & Nishihira, M. (1984): Ecological distribution of two types of the sea urchin Echinometra mathaei on Okinawa Reef Flat. Galaxea 3: 131–143. Ullrich-Lüter, Esther, M., Dupont, S., Arboleda, E., Hausen, H. & Arnone, M. I. (2011): Unique system of photoreceptors in sea urchins tube feet. Proceedings of the National Academy of Sciences of the US 108: 8367–8372. Vance, R. R. (1979): Effects of grazing by the sea urchin Centrostephanus coronatus, on prey community composition. Ecology 60: 537–546. Vasseur, E. (1952): Geographic variation in the Norvegian sea-urchins Strongylocentrotus droebachiensis and S. pallidus. Evolution 6: 87–100. Weinberg, S. & de Ridder, C. (1998): Asthenosoma marisrubri from the Red Sea. Beaufortia 48: 27–46. Williams, D. H. C. & Anderson, D. T. (1975): The reproductive system, embryonic developmental larval development and metamorphosis of the sea urchin Heliocidaris erythrogramma. Australian Journal of Zoology 23: 371–403. Young, C. M. & George, S. B. (2000): Larval development of the tropical deep-sea echinoid Aspidodiadema jacobyi: phylogenetic implications. Biological Bulletin 198: 387–395. Yusa, Y. & Yamamoto, T. (1994): Inside or outside the pits: variable mobility in conspecific sea urchin Anthocidaris crassispina. Publications of the Seto Marine Biological Laboratory 36: 255–266. Zigler, K. S. & Lessios, H. A. (2004): Speciation on the coasts of the New World: phylogeography and the evolution of bindin in the sea urchin genus Lytechinus. Evolution 58: 1225–1241.

Acknowledgments Many people kindly supported me. Without their help, I would not have been able to write this books on echinoids. Thanks to Claus Nielsen and Tom Schiötte, Zoological Museum Copenhagen, for making available to me specimens of the echinoid collection of Th. Mortensen. I reveled in examining echinoids and photographing all I needed. Thanks to Carsten Lüter, Museum für Naturkunde, Berlin, for allowing me to take pictures of specimens housed in the collection, just before they were moved into the rooms of the newly built, state-of-the-art, wet collection. Thanks to Andreas Schmidt-Rhaesa and Peter Stiewe for making it possible to work in the echinoid collection of the Zoological Institute and Museum of the University of Hamburg. I felt at home in that basement. Many thanks to Andreas Schmidt-Rhaesa in his role as chief editor of the Handbook of Zoology for his help with bringing text and figures into the right format. Thanks to Jane Pigney and Lars Rose, Berwick-uponTweed, UK, for editing my English. They learned much about echinology. Thanks to Susanne J. Lockhart, San Diego, CA, USA, for many time-consuming discussions. Thanks for answering questions, for pictures, for specimens, for literature, and for good advice to the following: –– Owen F. Anderson, National Institute of Water & Atmospheric Research Ltd., Wellington, New Zealand –– Kate Attwood and Stephen Keable, Australian Museum, Sydney, Australia –– Andrew Cabrinowic and Harry Taylor, The Natural History Museum, London, UK –– Luc Ceulemans, Rhode Saint Genèse, Belgie –– Willi Clarenbach, Haan, Germany –– Simon E. Coppard, Smithsonian Tropical Research Institute, Balboa, Panama

–– Bruno David, Biogéosciences, Université de Bourgogne, Dijon, France –– Heidi Friedhoff, (HF) Norderstedt, Germany –– Gordon Hendler, Natural History Museum of Los Angeles County, Los Angeles, CA, USA –– Takashi Ito, Shizuoka, Japan –– Roland und Renate Kraft, Groß-Grönau, Germany –– Andreas Kroh, Naturhistorisches Museum, Vienna, Austria –– Harileos A. Lessios, Smithsonian Tropical Research Institute, Balboa, Panama –– Rich Mooi, California Academy of Sciences, San Francisco, CA, USA –– Christian Neumann, Museum für Naturkunde, Berlin, Germany –– Henk van Noordenburg, Leusden, The Netherlands –– Doris J. and David L. Pawson, National Museum of Natural History, Smithsonian Institute, Washington, DC, USA –– Bernhard Ruthensteiner, Zoologische Staatssammlung, Munich, Germany –– Andrew B. Smith, The Natural History Museum, London, UK –– Bas van der Steld, Zoetermeer, the Netherlands –– Hans-Volker Thiel, (VT) Bonn, Germany –– Esther Ullrich-Lüter, Berlin, Germany And last but not least, thanks to my husband Peter, who accompanied me in this work for many years, encouraging me to go on and helping me with numerous “small” technical things that turned out to be so important. I am grateful to all of you. Heinke Schultz

Glossary English

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Français

aboral

Upper side, opposite to mouth

Oberseite, dem Mund gegenüber

Sur la face du test opposée à la bouche

adapical

Toward apical system

Zum Apikalsystem hin

Sur la face du test où se trouve le système apical

adoral

Toward mouth

Zum Mund hin

Sur la face du test où se trouve la bouche

ambitus

Greatest horizontal circumference of test

Größter horizontaler ­Gehäuseumfang

La plus grande circonférence ­horizontale du test

ambulacra, ambulacral

Five segments of test reaching from apical system to peristome, ­alternating with interambulacra, perforated by ambulacral pores

Fünf Gehäusesegmente, vom ­Apikalsystem zum Peristom ­reichend, abwechselnd mit ­Interambulakra, perforiert durch paarige Ambulakralporen

Cinq secteurs du test s’étendant de l’appareil apical au peristome, alternant avec les ­interambulacres, et pourvus de paires de pores ambulacraires

ampulla

Contractile chamber of water v­ ascular system internal to test ­associated with external tube feet

Zweig des inneren WassergefäßSystems, ­zusammenziehbar und durch die Poren mit den äußeren Füßchen verbunden

Vésicule du système aquifère interne, en communication avec les podia externes par l’intermédiaire des pores ambulacraires

apical system

Plates of aboral summit of ­ambulacra and interambulacra consisting of genital and ocular plates

Platten am oberen Zusammenschluß von Ambulakra und ­Interambulakra, bestehend aus Genital- und ­Okularplatten

Ensemble des plaques génitales et oculaires situé au center de la face aborale du test

apophysis

Internal structures for attachment of muscles supporting lantern in interambulacral position (only in cidaroids)

Innere Pfeiler zum ­Befestigen der Laternen-Muskeln in ­interambulakraler Position (nur bei Cidaroiden)

Structure interambulacraire saillante de l’anneau pérignathique interne sur laquelle viennent s’insérer les muscles ­supportant la lanterne d’Aristote. Existe ­uniquement chez les cidaroidés

areole

Smooth depression around tubercle for attachment of muscles controlling movement of spines

Glatte Vertiefung um Stachelwarzen herum, dient zum Befestigen der Muskeln, die die Bewegung der Stacheln kontrollieren

Dépression lisse entourant les ­tubercules sur laquelle viennent s’insérer les muscles contrôlant les mouvements des piquants

Aristotle’s lantern

Jaw apparatus, with maximum 35 skeletal elements serving for ­mastication (“lantern”)

Kauapparat mit maximal 40 ­Skelett-Elementen (“Laterne”)

Appareil masticateur ­comportant au maximum 40 éléments ­squelettiques

aulodont lantern

Lantern with open upper end to pyramid and short epiphyses; the teeth with U-shaped cross section

Laterne, am oberen Ende offen, mit kleinen Epiphysen; die Zähne mit U-förmigem Querschnitt

Type de lanterne d’Aristote ­comportant une cavité profonde et de petites épiphyses. Profil des dents en forme de U

auricle

Internal structures for attachment of muscles supporting lantern in ambulacral position (only in ­euechinoid Regulars)

Innere Pfeiler zum Befestigen der Muskeln der Laterne in ­ambulakraler Position (nur in ­euechinoiden Regulären)

Structure ambulacraire saillante de l’anneau pérignathique interne sur laquelle viennent s’insérer les muscles supportant la lanterne d’Aristote. Existe uniquement chez les oursins euéchinoidés réguliers

bourrelets

Externally inflated parts of ­interambulacral areas around the peristome (in cassiduloids)

Äußerlich aufgewölbte ­Gehäusepartien in Interambulakra direkt um das Peristom herum (in Cassiduloida)

Parties renflées de l’interambulacre entourant le péristome chez les oursins cassidulidés

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buccal membrane, buccal plates, buccal pores

Membrane covering the opening of the peristome, usually set with ten buccal plates, each perforated by a pair of buccal pores with one podium. Remaining membrane more or less covered with platelets

Membrane, die die ­Peristom-Öffnung bedeckt, besetzt mit zehn ­Buccalplatten, jede mit einem Porenpaar (Buccalporen) und einem Buccal-Füßchen versehen; übrige Membran mehr oder weniger mit Plättchen bedeckt

Membrane couvrant l’ouverture de la bouche, comportant dix plaques buccales, chacune perforée d’une paire de pores buccaux reliés à un seul pied ambulacraire

buccal notch

Ten interambulacral indentations at peristomial edge of test, where buccal sacs protrude

Zehn interambulakrale ­Einbuchtungen an der ­peristomialen Gehäusekante, wo Buccalsäcke austreten

Dix indentations peristomiennes en position interambulacraire sur ­lesquelles s’insèrent les sacs buccaux

buccal sacs

External organs united with the internal cavity for compensating for changes of pressure, when the lantern moves in and out

Buccal-Säcke: zehn äußere Organe, verbunden mit der inneren ­Körperhöhle, zum Druckausgleich beim Bewegen der Laterne

Sacs buccaux externes ­communiquant avec la cavité interne pour compenser la pression lors de la mastication

buttress

Internal ridge or bridge of ­skeleton material connecting oral and aboral side for more stability of flat ­clypeasteroid tests

Skelettpfeiler (oder -brücke), der intern Ober- und Unterseite ­verbindet zur größeren ­Stabilität der flachen Gehäusen von ­Clypeasteroiden

Chez les oursins plats, anneau situé dans la partie interne du test permettant la communication entre partie orale et aborale pour une meilleure stabilité

camarodont lantern

Lantern with upper end of pyramid closed by epiphysis; the teeth with T-shaped cross-section (keeled)

Laterne, das obere Ende durch die Epiphyse geschlossen; ­Zahnquerschnitt T-förmig (gekielt)

Type de lanterne d’Aristote comportant une cavité profonde ­entièrement fermée par des é­piphyses qui se rejoignent. Profil des dents en forme de T

collar

Smooth tapering portion of spine above milled ring

Glatter, schmaler werdender Teil des Stachels oberhalb des ­gekörnelten Rings.

Anneau lisse situé dans la partie basale du piquant, juste au dessus du bourrelet strié

compound plate

Ambulacral plate unit composed of two or more individual plates, each with pore pair for tube foot, bound together by single large primary tubercle

Einheit von ­Ambulakralplatten ­ estehend aus 2 oder mehr b ­Einzelplatten mit jeweils einem Porenpaar für Füßchen, ­zusammengehalten von einer großen Primärwarze

Plaque ambulacraire composée résultant de la fusion de deux ou plusieurs plaques individuelles, comportant un seul tubercule primaire mais plusieurs paires de pores

conjugate pores

Pores of pair connected by groove in test

Durch eine Rinne verbundene Poren eines Paares

Pores d’une paire réunis par un sillon

corona

Principal skeleton, excluding apical, periproctal and peristomial plates

Eigentliches Kalkgehäuse ohne Apikal-, Periproktal- und ­Peristomialplatten

Partie majeure du test comportant ambulacres et interambulacres (excluant système apical, périprocte et péristome)

crenulate tubercle

Tubercle with cogged platform

Gekerbte Stachelwarzen

Tubercules crénelés

dicyclic

Type of apical system with only genital plates touching the ­periproctal margin, ocular plates in outer circle

Apikalsystem, in dem nur die ­ enitalplatten das Periprokt G ­berühren, Okularplatten bilden einen zweiten, äußeren Ring

Caractérise un appareil apical dans lequel seules les plaques ­génitales sont en contact avec l’aire ­périproctale, les plaques ocellaires formant un deuxième cercle

epiphysis

Element on top of lantern connected to pyramids

Kalkelement am oberen Ende der Laterne, das brückenartig die ­Pyramiden verbindet

Element de la lanterne, surmontant les demipyramides

episternal plates

Second pair of plates posterior to labral plate in echinoids with plastron

Zweites Plattenpaar hinter der L­ abralplatte, bei irregulären ­Echiniden mit Plastron

Chez les échinides irréguliers, deuxième paire de plaques situées après le labre

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ethmolytic

Type of apical system in which the madreporite extends posteriorly separating ocular plates I and V

Apikalsystem, in dem sich der ­Madreporit nach hinten erstreckt und die Okularplatten I und V trennt

Caracterise un appareil apical dans lequel le madreporite s’étend à l’arrière séparent les plaques ­ocellaires I et V

ethmophract

Type of apical system in which the genital plates 1, 2, 3, and 4 adjoin

Apikalsystem, in dem sich die ­Genitalplatten 1, 2, 3 und 4 ­berühren

Caracterise un appareil apical dans lequel les plaques genitales 1, 2, 3, et 4 sont en contact

exsert

Ocular plates not touching ­periproct

Okularplatten nicht in Kontakt mit Periprokt

Caractérise les plaques ocellaires qui ne sont pas en contact le ­périprocte

fasciole

Narrow band of small tubercles ­carrying tiny ciliated spines; cilia beat coordinately to create water currents

Schmales Warzenband, besetzt mit kleinen bewimperten Stacheln, deren Härchen durch ­koordiniertes Schlagen einen Wasserstrom erzeugen

Bande étroite recouverte de petits tubercules portant de fins piquants ciliés dont les mouvements créent des courants d’eau à la surface du test

floscelle

Star-shaped area around peristome formed by phyllodes and bourrelets (in cassiduloids)

Sternförmige Gehäusepartie um ­ eristom herum, gebildet von P ­Phyllodien und Bourrelets (in ­Cassiduloiden)

Chez les cassidulidés, structure du test en forme d’étoile entourant le peristome et formée par les ­phyllodes et les bourrelets

food groove

Narrow ambulacral groove leading to peristome supplied with ­specialized podia for food ­gathering and transport (may extend into ­interambulacra or aboral side)

Schmale Rinne in oralen ­Ambulakra, die zum Peristom führt; ­versehen mit spezialisierten Füßchen zur N­ahrungsaufnahme und zum ­Transport; kann auch in ­Interambulakra oder auf Aboralseite vorkommen

Sillon étroit situé dans l’ambulacre oral et conduisant au ­péristome. Il comporte des pieds ­ambulacraires spécialisés dans la collecte et le transport de la ­nourriture. Il peut s’étendre à la zone ­interambulacraire ou sur la partie aborale

genital plate

Apical plate usually with 1 pore for discharge of genital products in interambulacral position

Apikalplatte mit einer oder mehr Poren zum Ausströmen der Geschlechtsprodukte in ­interambulakraler Position

Plaque de l’appareil apical située en position interambulacraire et comportant un ou plusieurs pores génitaux pour le transfert du ­matériel génital

gonad

Genital organ in internal cavity

Geschlechtsorgan im Inneren des Gehäuse

Organe génital situé à l’interieur du test

gonopore

Genital pore

Geschlechtspore

Pore génital

globiferous ­pedicellaria

Type of pedicellaria with 3 valves containing poison

Pedizellarientyp mit 3 giftgefüllten Klappen

Type de pédicellaire à trois valves contenant du venin

insert

Terminal plates touching the edge of periproct

Terminalplatten in Kontakt mit Periprokt

Caractérise les plaques ­ocellaires qui sont en contact avec le ­périprocte

Interambulacra, interambulacral

Five segments of test reaching from apical system to peristome, ­alternating with ambulacra, not perforated

Fünf Gehäusesegmente, vom ­Apikalsystem zum Peristom ­reichend, abwechselnd mit ­Ambulakra, ohne Poren

Cinq secteurs du test s’étendant de l’appareil apical au peristome, alternant avec les ambulacres et dépourvus de pores

internal fasciole

Fasciole surrounding apical system, crossing all petals

Fasziole, die Apikalsystem umgibt, kreuzt dabei alle Petalodien

Fasciole entourant le système apical en croisant les 5 pétales ­ambulacraires

interporiferous zone

Area between inner series of ­ambulacral pores

Gehäusepartie zwischen inneren Ambulakralporen

Zone située dans les ambulacres, entre deux colonnes de pores

irregular

Echinoids with periproct located outside of circle of genital plates; with bilateral symmetry

Echiniden, bei denen das Periprokt außerhalb des Genitalplatten-Rings liegt, mit bilateraler Symmetrie

Caractérise un oursin à symétrie bilatérale dont le périprocte est situé en dehors du système apical

labrum, labral plate

More or less enlarged or modified liplike plate bordering peristome in interambulacrum 5 in irregulars

Mehr oder weniger vergrösserte oder modifizierte lippenähnliche Platte, die in Interambulakrum 5 ans Peristom stößt (in Irregulären)

Chez l’oursin irrégulier, plaque de l’interambulacre 5 bordant le ­péristome, plus ou moins agrandie et en forme de lèvre

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lantern

 = Aristotle’s lantern

 = Laterne des Aristoteles

 = lanterne d’Aristote

lateral fasciole

Fasciole extending posteriorly of peripetal fasciole; latero-anal if ­connected with anal fasciole

Fasciole, die sich hinter der ­Peripetalfasziole erstreckt; ­lateroanal, wenn verbunden mit Analfasziole

Fasciole s’étendant audelà du fasciole péripétale. Il est nommé latéroanal s’il vient en contact avec le fasciole anal

Lovenian system

Numbering system: ambulacra labeled from I to V, interambulacra from 1 to 5

Nummerierungssystem: Ambulakra zählen von I bis V, Interambulakra von 1 bis 5

Système de numérotation des plaques selon Lovén dans lequel les ambulacres sont numérotés de I à V et les interambulacres de 1 à 5

lunule

Opening that pierces the test at ambulacral and/or interambulacral sutures

Gehäuseöffnung von der aboralen zur oralen Seite an ­ambulakralen und/ oder interambulakralen Suturen

Perforation traversant le test de part en part et située dans la suture ambulacraire et/ou ­interambulacraire

madreporite

Sieve plate; through its pores the internal water vascular system is connected to the exterior

Siebplatte; durch die Poren ist das innere Wassergefäß-System mit der äußeren Umgebung verbunden

Plaque percée de nombreux ­hydropores reliant le système aquifère interne au milieu extérieur

margin

Ambitus of corona in flattened (­irregular) echinoids

Größter Gehäuseumfang bei eher flachen (irregulären) Echiniden

Contour le plus large chez les oursins plats (irréguliers)

marginal fasciole

Fasciole around ambitus just above margin passing beneath periproct

Fasziole führt oberhalb des Randes um das Gehäuse herum

Fasciole entourant le test audessus de l’ambitus

microcanal system

System of canals within plates of corona containing secondary branches of water vascular system leading to accessory podia (only in clypeasteroids)

Kanalsystem innerhalb der ­Gehäuseplatten, das mit klenen Ästen des Wassergefäß-Systems zu den zusätzlichen Füßchen führt (nur bei Clypeasteroiden)

Chez les clypéastéroïdes, ­ramifications du système aquifère reliant les pieds ambulacraires

miliary tubercle, miliary spine

Very small tubercles set with very small spines

Sehr kleine Warzen besetzt mit ­winzigen Miliärstacheln

Tubercules secondaires, portant les piquants secondaires

milled ring

Flange near base of spine for ­attachment of muscles moving spines

Gekörnelter Ring nahe der ­Stachelbasis zum Befestigen der Bewegungsmuskeln

Bourrelet strié situé à la base du piquant permettant l’insertion des muscles

monobasal

Type of apical system with a single genital plate, or with sutures of plates obliterated

Apikalsystem mit einer ­Genitalplatte, oder mit ­ausgelöschten Suturen

Type de système apical avec des plaques génitales fusionnées en une seule grande plaque

monocyclic

Type of apical system with one circle of genital and terminal plates ­contacting the periproct

Apikalsystem, in dem Genital- und Terminalplatten in einem einzigen Ring das Periprokt berühren

Caractérise un système apical où les plaques génitales et ocellaires sont en contact avec le périprocte, formant un seul cercle

ocular plate, ocular pore

Plate in apical system at the summit of ambulacra, perforated by single ocular pore associated with ocular tentacle

Platte im Apikalsystem, den ­Ambulacra zugeordnet, perforiert von einzelner Okularpore mit Okularfüßchen

Plaque perforée d’un seul pore avec un seul podion et située dans l’appareil apical, au sommet de l’ambulacre

oral

Underside, opposite to the upper (aboral) side

Auf der Unterseite, der Aboralseite gegenüber

Sur la face du test qui porte la bouche

­pedicellariae ­(singular ­pedicellaria)

Minute stalked pincer-like valves specialized for cleaning the surface or defense (with poison glands)

Winzige, gestielte Klappen, die wie Pinzetten greifen; zur Reinigung der Gehäuseoberfläche oder zur­ ­Verteidigung (mit Giftdrüsen)

Petits appendices en forme de pince comportant plusieurs valves. Ils ont à la fois un rôle de nettoyage et un rôle défensif (glande à venin)

perforate tubercle

Tubercle with small pit in top for ­ligament connecting spine with tubercles

Stachelwarze mit kleiner Vertiefung in der Spitze für das Ligament, das Stachel und Warze verbindet

Tubercule perforé

Glossary 

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perignatic girdle

Continuous or discontinuous ring of internal processes around ­peristomial opening for ­attachment of muscles supporting and ­controlling lantern

Durchgehender oder unterbrochener Ring von Kalkstrukturen entlang der inneren Gehäusekante am Peristom zum Befestigen von Muskeln des Kauapparates

Anneau continu ou discontinu de structures internes entourant le péristome. Permet l’insertion des muscles supportant et commandant les mouvements de la lanterne d’Aristote

periproct

Opening in test for anus, covered in life by periproctal membrane, usually plated

Gehäuseöffnung für den After, im Leben mit Periproktal-Membran verschlossen, i.allg. mit Platten bedeckt

Ouverture du test pour l’anus. ­Couverte d’une membrane ­périproctale chez l’oursin vivant

peristome

Opening of test for mouth, covered in life by peristomial membrane, usually plated

Gehäuseöffnung für den Mund, im Leben mit Peristomial-Membran verschlossen, mit Platten bedeckt

Ouverture du test pour la bouche. Couverte d’une membrane ­péristomiale chez l’oursin vivant

petal

Leaf-shaped arrangement of aboral pore zones with more or less enlarged tube feet specialized for respiration

Blattförmige Anordnung von aboralen Porenzonen mit mehr oder weniger vergrösserten ­Atem-Füßchen

Sur la face aborale, zone ­ambulacraire différenciée en forme de pétale

phyllode

More or less leaf-shaped ­ rrangement of oral pore pairs a with enlarged tube feet for food gathering

Mehr oder weniger blattförmige Anordnung von oralen ­Porenpaaren mit vergrößerten Füßchen zum Greifen von Nahrung

Structure particulière au ­voisinage de la bouche résultant d’un ­arrangement des pores ­ambulacraires où les podia sont plus grands et permettent de ­collecter davantage de nourriture

plastron

More or less inflated or enlarged area in oral interambulacrum 5 in irregulars

Mehr oder weniger aufgewölbte oder vergrößerte Gehäusepartie im oralen Interambulacrum 5 in Irregulären

Chez les oursins irréguliers, sur la face orale, partie de l’ambulacre 5 plus ou moins renflée et élargie

plate

Individual skeletal element more or less flattened, composed of single calcite crystal; columns of plates form the test

Einzelnes mehr oder weniger flaches Skelettelement bestehend aus einem einzigen Kalzitkristall; Plattenreihen bilden das Gehäuse

Elément de base du squelette composé de calcite. L’ensemle des plaques forme le test

podia (singular podium)

 = tube feet

 = Füßchen

 = podion (pluriel podia)

pore pair

Paired ambulacral pore divided by skeletal wall connecting single tube foot to the interior ampulla

Paarige Ambulakralporen, unterteilt durch Skelettbrücke, durch welche ein einzelnes Füßchen austritt

Paire de pores ambulacraires. Ils sont séparés par une cloison et communiquent avec un seul podion

primary tubercle, primary spine

First formed and usually largest tubercles set with larger primary spines

Zuerst gebildete und i.allg. größere Warzen mit größeren Stachelm (Primärstachel)

Tubercule de grande taille portant le piquant primaire

pyramids

Five large beak- or wing-like ­elements of lantern

Fünf große schnabel- oder ­flügelförmige Elemente in der Laterne

Eléments de la lanterne, au nombre de cinq

regular

With periproct within the ring of genital and ocular plates; with pentameral symmetry

Mit dem Periprokt innerhalb des Rings von Genital- und ­Okularplatten, mit pentagonaler Symmetrie

Caractérise un oursin à ­symétrie pentaradiale et dont le ­périprocte est situé dans l’anneau ­génitooculaire

scrobicular ­tubercle, ­scrobicular spine

More or less complete ring of ­tubercles set with scrobicular spines around areole in cidaroids

Mehr oder weniger ­vollständiger Ring von Warzen besetzt mit ­Skrobikularstacheln um Areole herum, nur bei Cidaroiden

Chez les cidaroidés, tubercules formant un anneau circulaire qui entoure le tubercule primaire. Ils portent les piquants scrobiculaires

secondary ­tubercle, ­secondary spine

Intermediate-sized tubercle set with intermediate-sized secondary spine, appearing later than primary spine

Mittelgroße Warzen mit ­mittelgroßen ­Sekundärstacheln, erscheinen später als ­Primärstacheln

Tubercule de taille intermédiaire portant le piquant secondaire

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 Glossary

English

Deutsch

Français

sieve plate

 = Madreporite

Siebplatte = Madreporite

 = madréporite

spheridia

Minute spherically modified spines on short stems generally situated at oral side in pits

Winziges, gestieltes, kugelförmig verändertes Stachechen, i.A. auf der Unterseite in Grübchen liegend

Organes microscopiques, sphériques, correspondant à des piquants modifiés. Généralement situés dans des cavités sur la face orale du test

spine

More or less cylindrical, external calcareous rod movable on tubercle and articulated with it

Stachel; externer, mehr oder weniger zylindrischer, kalkiger Stab, durch Kugelgelenk beweglich mit Warze verbunden

 = piquant ou radiole. Tige calcaire rigide plus ou moins cylindrique située à la surface du test, articulée sur le tubercule

sternal plates

First pair of plates posterior to labrum in echinoids with plastron

Erstes Plattenpaar hinter der ­Labralplatte bei Echiniden mit Plastron

Chez les oursins irréguliers, plaques de l’interambulacre 5 situées juste derrière le labre

stirodont lantern

Lantern with open upper end to pyramids, the teeth with T-shaped (keeled) cross section

Laterne, oben offen zu den ­Pyramiden; der Zahnquerschnitt T-förmig (gekielt)

Type de lanterne d’Aristote c­ omportant une cavité profonde et des épiphyses qui ne se rejoignent pas. Profil des dents en forme de T

subanal fasciole

Fasciole on posterior side of test below periproct enclosing more or less elliptical area

Fasziole, die eine mehr oder weniger elliptische Gehäusepartie am Hinterende unterhalb des Periprokts umschließt

Chez l’oursin irrégulier, fasciole entourant une surface plus ou moins elliptique située sous le périprocte

sutures

Seam marking contact between ­ djacent plates, usually a ­recognizable by fine line on surface of test

Naht zwischen benachbarten Platten, i.- allg. sichtbar als feine Linie auf der Gehäuseoberfläche

Zone de contact entre des plaques adjacentes, marquée par une ligne fine à la surface du test

test

Collective name of plates of coronal, apical, periproctal and peristomial systems

Gehäuse, Sammelname für ­K­oronal-, Apikal-, Periproktal- und ­Peristomialplatten

Squelette de l’oursin constitué des plaques coronales, périproctales, péristomiennes et apicales

tooth

Calcareous rod in pyramid, with sharpened end protruding at lowest point of lantern

Kalkstab in Pyramide, mit scharfem Ende, tritt an unterer Spitze der Laterne aus

Elément squelettique de la lanterne d’Aristote en forme de longue dent dont l’extrémité aiguisée dépasse à l’extérieur du test

tube foot

 = podium: external end of branch of water vascular system ­protruding of pore pairs, serving for ­grasping, adhesion, locomotion and ­respiration

Füßchen: äußeres Ende der Äste des inneren Wassergefäß-Systems, tritt aus Porenpaar aus; dient zum Greifen, Anheften, ­Vorwärtsbewegen und Atmen

 = podion. Terminaison externe du système aquifère, connecté à celuici par l’intermédiaire des pores ­ambulacraires. Les podias sont impliqués dans la respiration, la nutrition, la locomotion et la fixation au substrat

water vascular system

Through the pores of the ­madreporite, the ring canal is ­connected with the free water. The five radial canals lead into the ­ambulacra and branch to each­ ­internal ampulla connected through the pores with the external tube foot. The radial canals end in the ­terminal tentacle, protruding through the terminal pores

Wassergefäß-System: Durch die Poren der Siebplatte steht der Ringkanal mit dem freien Wasser in Verbindung. Von ihm führen die Radialkanäle in die Ambulakra, wo sie zu jeder inneren Ampulle abzweigen, durch das Porenpaar mit jeweils einem äußeren Füßchen verbunden. Die Radialkanäle enden in den Terminalfüßchen, die aus den Terminalporen austreten

Système aquifère interne débutant par un canal circulaire connecté au milieu extérieur par l’intermédiaire des pores de la madréporite. Ce canal se ramifie en 5 canaux radiaux courant le long des ambulacres. Ces canaux se ramifient à leur tour, conduisant à des ampoules qui ­communiquent avec les podia externes au travers des pores ­ambulacraires

After J. W. Durham et al. 1966. Treatise on Invertebrate Palaeontology. Vol. U 3 (1).

Index Abatus cordatus 13 abnormalis, Gymnechinus 335 abyssale, Kamptosoma 136 abyssicola, Cidaris 31, 32 Acanthocidaris 21, 23, 25 – Acanthocidaris curvatispinis 25, 26, 27, 28 – Acanthocidaris hastigera 25, 27, 28 – Acanthocidaris maculicollis 25, 27, 28 aciculatus, Echinostraphus 302 Acroechinoidea 1, 2, 10, 14, 15, 16, 21, 157, 158 acutispina, Histocidaris 127 acutus, Gracilechinus 281, 282, 283 adenicum, Phormosoma 139 affinis, Gracilechinus 281, 282, 283 affinis, Stylocidaris 34, 58, 60 africana, var. Phormosoma placenta 139 africanum, Aspidodiadema 162, 164 africanum, Chaetodiadema 173, 174 agassizi, Prionechinus 268, 269 agassizii, Sterechinus 290, 292 agulhensis, Polyechinus 289 alanbakeri, Caenopedina 190 alba, Goniocidaris 94, 95, 98, 104 albida, Trigonocidaris 270, 271 albidens, Stylocidaris 58, 60 albocinctus, Pseudechinus 242 albodoides, Trigonocidaris 263, 270 albus, Loxechinus 294, 316, 318, 319 albus, Opechinus 238, 239 alcocki, Stereocidaris 114, 115 alexandri, Gracilechinus 281, 282, 283, 286 alexandri, Temnopleurus 251, 252, 255 Allocentrotus 22, 324 – Allocentrotus fragilis 329 alternans, Paraphormosoma 137, 138 alternatum, Araeosoma 140 Amblypneustes 22, 221, 222, 226 – Amblypneustes elevatus 222, 223 – Amblypneustes formosus 222, 224 – Amblypneustes grandis 222 – Amblypneustes leucoglobus 222, 223, 224 – Amblypneustes ovum 222, 223, 225 – Amblypneustes pallidus 222, 223, 225 – Amblypneustes pulchellus 222, 223 amboina, Stylocidaris 58, 61 ambonensis, Nudechinus 344, 345 amphigynmum, Plesiodiadema 160, 162 Amphipneustes bifidus 4 Amphipneustes lorioli 18 Amphipneustes marsupialis, 13 amynina, Hapalosoma 150 anamesus, Lytechinus 337, 340 anatirostrum, Araeosoma 140 anchistus, Echinus 275, 276 angulosus, Parechinus 4, 319, 321, 322 annulata, Caenopedina 190, 191

annulatus, Microcyphus 232, 235 annulifera, baculosa, Prionocidaris 52 annulosa, Stylocidaris 58, 61 anomalus, Desmechi 265 antarctica, Aporocidaris 74, 75 antarcticus, Sterechinus 290, 291, 292 Anthocidaris 306 – Anthocidaris crassispina 308 antillarum, Diadema 11, 177, 178, 179 antillarum, Plesiodiadema 160, 161, 162 antillense, Sperosoma 154 Antrechinus mortenseni 13 aotearoa Ctenocidaris 80, 81 apodus, Temnopleurus 251, 252, 253 Aporocidaris 21, 74 – Aporocidaris antarctica 74, 75 – Aporocidaris eltaniana 74, 75 – Aporocidaris fragilis 74, 77 – Aporocidaris incerta 13, 74, 78, 79, 80 – Aporocidaris milleri 74, 77, 78 – Aporocidaris usarpi 74, 75, 78 Araeosoma 21, 139 – Araeosoma alternatum 140 – Araeosoma anatirostrum 140 – Araeosoma bakeri 140 – Araeosoma coriaceum 142 – Araeosoma eurypatum 140, 142 – Araeosoma fenestratum 140, 142, 143 – Araeosoma leppienae 136 – Araeosoma thetidis 136 – Araeosoma violaceum 136 Arbacia 22, 203, 218 – Arbacia dufresnii 204, 205 – Arbacia lixula 203, 204, 205 – Arbacia punctulata 203, 204, 206 – Arbacia spatuligera 204, 207, 208 – Arbacia stellata 204, 207, 209 Arbaciella 22, 203, 207, 214 – Arbaciella elegans 207, 209 Arbaciidae 22, 201, 203 Arbacina 220 Arbacioida 22, 201, 203, 214 arcitum, Aspidodiadema 162, 164 Areosoma belli 140 – Areosoma bidentatum 140 – Areosoma coriaceum 140, 143 – Areosoma leppienae 140, 142 – Areosoma leptaleum 140, 143 – Areosoma migratum 140, 144 – Areosoma owstoni 141, 144, 145 – Areosoma parviungulatum 141, 144 – Areosoma paucispinum 141, 144, 145 – Areosoma splendens 141, 144 – Areosoma tertii 141, 144 – Areosoma tesselatum 141, 144, 146 – Areosoma thetidis 141, 145, 146

376 

 Index

Areosoma violaceum 141, 146 argentea, Habrocidaris 215, 216 armatum, Sperosoma 154 armatus, Selenechinus 315 armigera, var., Heliocidaris erythrogramma 309, 310 ascensionis, Diadema 177 Aspidocidaris 94 – Aspidocidaris, Goniocidaris alba 94, 95, 98, 104 – Aspidocidaris, Goniocidaris australiae 94, 95, 96, 98 – Aspidocidaris, Goniocidaris clypeata 94, 97, – Aspidocidaris, Goniocidaris crassa 94, 98, 100 – Aspidocidaris, Goniocidaris fimbriata 94, 98, 100, 103 – Aspidocidaris, Goniocidaris indica 94, 101, 102, 103 – Aspidocidaris, Goniocidaris parasol 94, 103, 108 – Aspidocidaris, Goniocidaris sibogae 94, 98, 104, 105 Aspidodiadema 21, 159, 162 – Aspidodiadema africanum 162, 164 – Aspidodiadema arcitum 162, 164 – Aspidodiadema hawaiiense 162, 164, 165 – Aspidodiadema intermedium 162, 165 – Aspidodiadema jacobyi 162, 165 – Aspidodiadema meijerei 160, 162, 164 – Aspidodiadema montanum 162, 165 – Aspidodiadema nicobaricum 160, 162, 165, 166 – Aspidodiadema sinuosum 162, 166 Aspidodiadematidae 21, 159 Aspidodiadematoida 21, 158, 159 Aspidodoadema tonsum 162, 166 assimilis, Schizocidaris 112, 113 Asterechinus 22, 264 – Asterechinus elegans 264 asterias, Kamptosoma 135, 136, 137 asteriscus, Centrostaphanus 169, 170 asteriscus, Hesperocidaris 40, 41 Asteroidea 1 Asthenosoma 21, 139, 147 – Asthenosoma dilatatum 147 – Asthenosoma ijimai 147, 148 – Asthenosoma intermedium 147 – Asthenosoma marisrubri 147, 148, 149 – Asthenosoma periculosum 147, 148 – Asthenosoma varium 136, 142, 147, 148, 149 Astropyga 21, 167, 173, 185 – Astropyga magnifica 167, 168 – Astropyga pulvinata 167, 168, 169 – Astropyga radiata 167, 168, 169, 188 Atelostomata 6 atlantica, Pseudoboletia 347, 348 atlanticus, Gracilechinus 281, 284, 286 atratus, Colobocentrotus (Podophora)  295, 296, 297 australe, Tromikosoma 155, 156 australiae, Eucidaris 35, 36 australiae, Goniocidaris 94, 95, 96, 98, 104 australiae, Heliocidaris 306, 307 australiae, Histocidaris 127, 128 australiae, Pachechinus 306 australis, Coelopleurus 209, 211 australis, Monostychia 18 australis, Prionocidaris 51, 52, 53

Austrocidaris 21, 91 – Austrocidaris canaliculata 74, 91, 92 – Austrocidaris lorioli 91, 93 – Austrocidaris pawsoni 91, 93 – Austrocidaris spinulosa 91, 92, 93 baculosa, Prionocidaris 47, 51, 52, 54 badia, Stylocidaris 58, 62, 63 bajulus, Heliocidaris 306, 307, 308 bajulus, Pachechinus 306, 307 bajulus, Pachycentrotus 306, 307, 324 bakeri, Araeosoma 140 balinensis, Goniocidaris 95, 96 bartletti, Tretocidaris 72, 73 Bathysalenia 22, 195, 198 – Bathysalenia cincta 196, 198, 199 – Bathysalenia goesiana 196, 198, 199 – Bathysalenia phoinissa 198, 200 – Bathysalenia scrippsae 198, 200 – Bathysalenia sculpta 198, 200, 201 – Bathysalenia unicolor 198, 200, 201 belli, Araeosoma 140 belli, Salmacis 248, 249 benhami, Ogmocidaris 108, 109 bernasconiae, Sterechinus 290, 291 besnardi, Centrostephanus 169, 170, 173 bicolor, Salmacis 248, 249 bidentatum, Araeosoma 140 bifidus, Amphipneustes 4 biserialis, Goniocidaris 94, 95, 96 biseriatum, Sperosoma 154, 155 bispinosa, Prionocidaris 51, 52, 53, 55 blakei, Cidaris 31, 32 bothryoides, Temnotrema 257, 258, 259 brachygnata, Salenocidaris 195 bracteata, Stylocidaris 59, 62, 63 brevicollis, Stylocidaris 59, 62, 64 brevispina, Chondrocidaris 29, 31 bursarium, Phormosoma 136, 138, 140 Caenocentrotus 22, 292 – Caenocentrotus gibbosus 294, 318 Caenopedina 22, 189 – Caenopadina alanbakeri 190 – Caenopedina annulata 190, 191 – Caenopedina capensis 190, 191 – Caenopedina cubensis 190, 191, 192 – Caenopedina depressa 190, 191 – Caenopedina diomedeae 190, 191, 193 – Caenopedina hawaiiensis 190, 191, 192 – Caenopedina indica 190, 191, 193 – Caenopedina mirabilis 159 – Caenopedina mirabilis 190, 191, 193 – Caenopedina novaezealandiae 190, 192 – Caenopedina otagoensis 190, 194 – Caenopedina porphyrogigas 190, 194 – Caenopedina pulchella 190, 195 – Caenopedina superba 190, 195 calacantha, Stylocidaris 59, 64 calamaris, Echinothrix 181, 183, 184

Index 

callipeplus, Lytechinus 337, 338 callista, Prionocidaris 51, 52, 55, 56 Calocidaris 21, 23, 28 – Calocidaris micans 28 Calveriosoma 21, 139, 150 – Calveriosoma gracile 150, 151 – Calveriosoma hystrix 142, 150, 151 Calycina 22, 195 Camarodonta 7, 16, 22, 201, 218 canaliculata, Austrocidaris 74 canaliculata, Austrocidaris 91, 92 capensis, Caenopedina 190, 191 capensis, Stereocidaris 114, 115 Carinacea 16, 22, 195 carinata, Histocidaris 127, 128 carolinus, Lytechinus variegatus 340, 341 Cassiduloida 4, 16 Centrocidaris 21, 23, 29 – Centrocidaris doederleini 29 Centrostephanus 21, 167, 169 – Centrostephanus asteriscus var. malayanus 169 – Centrostephanus asteriscus 169, 170 – Centrostephanus besnardi 169, 170, 173 – Centrostephanus coronatus 169, 170, 171 – Centrostephanus longispinus 169, 170, 171, 173 – Centrostephanus nitidus 169, 171 – Centrostephanus rodgersii 159, 169, 172, 173, 311 – Centrostephanus rubricingulus 169, 173 – Centrostephanus silviae 169, 173 – Centrostephanus tenuispinus 169, 172, 173 ceylanicus, Microcyphus 232 Chaetodiadema 21, 167, 173, 174 – Chaetodiadema africanum 173, 174 – Chaetodiadema granulatum 173, 174, 175 – Chaetodiadema japonicum 173, 174, 175 – Chaetodiadema keisense 173, 174, 176 – Chaetodiadema pallidum 159, 173, 174, 176, 177 – Chaetodiadema tuberculatum 173, 174, 177 chilensis, Fabia/parasitic crab 294, 318 Chondrocidaris 21, 23, 29 – Chondrocidaris brevispina 29, 31 – Chondrocidaris gigantean 31 Cidaridae 14, 15, 21, 23 Cidarinae 21, 23 Cidaris 21, 23, 31 – Cidaris abyssicola 31, 32 – Cidaris blakei 31, 32 – Cidaris cidaris 31, 32, 33 – Cidaris nuda 31, 34 – Cidaris rugosa 31, 34, 35 Cidaroida 2, 14, 16, 21, 23, 25 Cidaroidea 1, 21, 23 cincta, Bathysalenia 196, 198, 199 cingulata, Stylocidaris 59, 64 clavata, var. tribuloides, Eucidaris 36, 39 cloroticus, Evechinus 305, 306 Clypeaster humilis 11 Clypeasteroida 3, 4, 10, 17 clypeata, Goniocidaris 94, 97 Clypeus plotii 17

cobosi. Histocidaris 127, 129 Coelopleurus 22, 203, 207, 210 – Coelopleurus australis 209, 211 – Coelopleurus exquisitus 209, 211, 214 – Coelopleurus floridanus 209, 212 – Coelopleurus granulatus 209, 212 – Coelopleurus interruptus 209, 213 – Coelopleurus longicollis 209, 210, 213 – Coelopleurus maculatus 209, 213, 214 – Coelopleurus maillardi 209, 213, 214 – Coelopleurus undulatus 209, 213, 215 – Coelopleurus vittatus 209, 214 Colobocentrotus 22, 294, 296 – Colobocentrotus (Colobocentrotus) mertensii 295, 296 – Colobocentrotus (Colobocentrotus) 295 – Colobocentrotus (Podophora) atratus 295, 296, 297 – Colobocentrotus (Podophora) pedifer 296, 297 – Colobocentrotus (Podophora) 295 Compsocidaris 21, 23, 35 – Compsocidaris pyrsacantha 35, 36, 117 compsus, Microcyphus 232, 234, 235 conferta, Stylocidaris 59, 65, 66 Coptechinus 220 cordatus, Abatus 13 coriaceum, Araeosoma 140, 142, 143 corona, Goniocidaris 94, 98, 99, 108 coronatus, Centrostaphanus 169, 170, 171 coronatus, Hypsiechinus 265, 267 crassa, Goniocidaris 94, 98, 100 crassispina, Anthocidaris 308 crassispina, Heliocidaris 306, 308, 327 crassispina, Salenocidaris 195 crassispins, Histocidaris 127, 129 crassispinum, Sperosoma 154, 156 crenularis, Glyptocidaris 201, 202 Crinoidea 1 Ctenocidarinae 21, 23, 73 Ctenocidaris 21, 74, 80, 82 – Ctenocidaris (Eurocidaris) nutrix 81 – Ctenocidaris aotearoa 80, 81 – Ctenocidaris geliberti 80, 81, 82, 85 – Ctenocidaris nutrix longispina 81 – Ctenocidaris nutrix nutrix 81 – Ctenocidaris nutrix 80, 82 – Ctenocidaris perrieri 76, 80, 81, 82, 83 – Ctenocidaris polyplax 80 – Ctenocidaris rugosa 80, 82, 83 – Ctenocidaris sp. 74 – Ctenocidaris speciosa 76, 80, 82, 83 – Ctenocidaris spinosa 81, 82, 83, 84 cubensis, Caenopedina 190, 191, 192 curvatispinis, Acanthocidaris 25, 26, 27, 28 Cypracassis rufa (Mollusca) 10 Cyrtechinus verruculatus 346 Cyrtocidaris 94 – Cyrtocidaris, Goniocidaris tenuispina 94, 105, 106 darnleyensis, Nudechinus 344, 345 darwini, Monophoraster 18 debilis, Eremopyga 183, 184, 185

 377

378 

 Index

decipiens, Temnopleurus 251, 252, 253 denticulata, Histocidaris 127, 128, 129 dentifer, Sterechinus 290, 291 denudata, Eremopyga 183, 185, 186 depressa, Caenopedina 190, 191 depressus, Pseudocentrotus 327, 328 depressus, Tripneustes 353, 356 Dermechinus 22, 274 – Dermechinus horridus 274, 275 Desmechinus 22, 264 – Desmechinus anomalus 265 – Desmechinus versicolor 265, 266 Diadema 21, 167, 177, 353 – Diadema antillarum 11, 177, 178, 179 – Diadema ascensionis 177 – Diadema mexicanum 177, 178, 179, 180 – Diadema palmeri 167, 177, 178, 179, 180 – Diadema paucispinum 177, 178, 181 – Diadema savignyi 177, 178, 181, 182, 183 – Diadema setosum 177, 178, 181, 182, 183 – diadema, Echinothrix 181, 183 – diadema, Sterechinus 290, 291, 293 Diadematacea 14, 16, 158 Diadematidae 21, 163, 167 Diadematoida 21, 159, 167 Dialithocidaris 22, 203, 214 – Dialithocidaris gemmifera 214, 216 dilatatum, Asthenosoma 147 diomedeae, Caenopedina 190, 191, 193 Disasteroida 16, 17 Discocidaris 94 – Discocidaris, Goniocidaris mikado 94, 102, 103 – Discocidaris, Goniocidaris peltata 94, 103, 104 djakonovi, Strongylocentrotus 328 doederleini, Centrocidaris 29 doederleini, Paratrema 238, 239, 240 droebachiensis, Strongylocentrotus 328, 329 dubia, Hesperocidaris 40, 41 dubius, Phyllacanthus 45, 46 dufresnii, Arbacia 204, 205 durum, Sperosoma 154 dussumieri, Salmaciella 245, 246 Echinacea 14, 16, 22, 201 Echinidae 22, 274 Echinidea 22, 201, 274 Echinodermata 1 Echinoida 22, 274 Echinoidea 1, 21 Echinometra insularis 298 Echinometra lucunter 298 Echinometra mathaei 14 Echinometra mathei 220, 298, 299, 300, 301 Echinometra oblonga 298, 301 Echinometra vanbrunti 298, 301, 302, 303 Echinometra viridis 298, 302, 303 Echinometridae 22, 274, 291 Echinophyces mirabilis (Parasite) 76 Echinostraphus molaris 302, 304 Echinostrephus aciculatus 302

Echinostrephus 22, 294, 302 Echinothrix calamaris 181, 183, 184 Echinothrix diadema 181, 183, 184 Echinothrix 21, 167, 177, 181 Echinothuria 135 Echinothuriidae 21, 135, 139 Echinothurioida 4 – Echinothurioida 1, 14, 21, 135, 159 – Echinothurioida 10 – Echinothurioida 14 echinulata, Psilocidaris 108, 110 Echinus 22, 274, 275, 281, 289 – Echinus anchistus 275, 276 – Echinus esculentus 275, 276, 277, 279, 280, 282, 351 – Echinus euryporus 276, 277 – Echinus gilchristi 1, 276, 278, 279 – Echinus melo 276, 279, 280 – Echinus multidentatus 276, 279, 280 – Echinus tenuispinus 276, 280 – Echinus tylodes 276, 281 – Echinus wallisi 276, 281 effluens, Stylocidaris 59, 65, 66 elatensis, Tripneustes gratilla 356, 358 elegans, Arbaciella 207, 209 elegans, Asterechinus 264 elegans, Desmechinus 264 elegans, Gracilechinus 276, 281, 284, 285, 287 elegans, Gracilechinus 4 elegans, Histocidaris 127, 129, 130 elegans, Temnotrema 258, 259 elegans, Toxopneustes 351, 352 elevatus, Amblypneustes 222, 223 elongata, Lovenia 11 eltaniana, Aporocidaris 74, 75 Eodiadema 16 epistichus, Gymnechinus 335, 337 Erbechinus 22, 221, 224 – Erbechinus spectabilis 224, 226 Eremopyga 21, 167, 169, 183 – Eremopyga debilis 183, 184, 185 – Eremopyga denudata 183, 185, 186 eryathracis, Salmaniella 245, 246 erythrogramma, Heliocidaris 13, 306, 309, 310, 311 esculentus, Echinus 275, 276, 277, 279, 280, 282, 351 Eucidaris 21, 23, 35, 353 – Eucidaris australiae 35, 36 – Eucidaris galapagensis 35, 37 – Eucidaris metularia 35, 37, 38, 47 – Eucidaris thouarsii 11, 35, 37, 38 – Eucidaris tribuloides var. clavata 36, 39 – Eucidaris tribuloides 35, 38, 39 Euechinoidea 1, 14, 21, 135 euerces, Lytechinus 337, 338 Eurocidaris, Ctenocidaris nutrix 81 eurypetalum, Araeosoma 140, 142 euryporus, Echinus 276, 277 Evechinus 22, 294, 305 – Evechinus chloroticus 305, 306 excavata, Stereocidaris 115, 116

Index 

excentricus, Microcyphus 232, 234 exquisitus, Coelopleurus 209, 211, 214 Fabia chilensis (parasitic crab) 294, 318 fasciata, Schizocidaris 112 fenestratum, Araeosoma 140, 142, 143 Fibularia japonica 12 fimbriata, Goniocidaris 94, 98, 100 flemingi, Gracilechinus acutus 284 flemingi, Pseudechinus 242, 243 floridanus, Coelopleurus 209, 212 florigera, Goniocidaris 94, 98, 100 forbesianus, Prionechinus 268, 269 forcipulatus, Phyllacanthus 45, 46 formosa, Histocidaris 127, 129, 130 formosus, Amblypneustes 222, 224 fragilis, Allocentrotus 329 fragilis, Aporocidaris 74, 77 fragilis, Strongylocentrotus 328, 329, 330 franciscanus, Mesocentrotus 325, 326 franciscanus, Strongylocentrotus 325 fusca, Lissocidaris 43, 45 fusispina, Stylocidaris 59, 65 gaimardi, Paracentrotus 319, 321 galapagensis, Eucidaris 35, 37 gaussensis, Notocidaris 85, 86 geliberti, Ctenocidaris 80, 81, 82, 85 geliberti, Ctenocidaris 85 gemmifera, Dialithocidaris 214, 216 gemmiferum, Hapalosoma 150, 151 Genocidaris 22, 264, 265 – Genocidaris maculata 265, 266 gibbosus, Caenopedina 294, 318 gigantea, Chondrocidaris 31 gigantea, Homalocidaris, 81, 84, 85 giganteum, Sperosoma 154 gilchristi, Echinus 1, 276, 278, 279 glandulosa, Prionocidaris 51, 56 globulosum, Plesiodiadema 160, 161, 162 globulus, Mespilia 230, 231, 232, 356 Glyptocidaridae 22, 201 Glyptocidaris 22, 201 – Glyptocidaris crenularis 201, 202 goesiana, Bathysalenia 196, 198, 199 Goniocidarinae 21, 23, 91 Goniocidaris 21, 91, 93 – Goniocidaris ((Aspidocidaris) sibogae 94, 98, 104, 105 – Goniocidaris (Aspidocidaris) alba 94, 95, 98, 104 – Goniocidaris (Aspidocidaris) australiae 94, 95, 96, 98, 104 – Goniocidaris (Aspidocidaris) clypeata 94, 97 – Goniocidaris (Aspidocidaris) crassa 94, 98, 100 – Goniocidaris (Aspidocidaris) fimbriata 94, 98, 100 – Goniocidaris (Aspidocidaris) indica 94, 101, 102, 103 – Goniocidaris (Aspidocidaris) parasol 94, 103, 108 – Goniocidaris (Aspidocidaris) 94 – Goniocidaris (Cyrtocidaris) 94 – Goniocidaris (Cyrtocidaris) tenuispina 94, 105, 106 – Goniocidaris (Discocidaris) mikado 94, 102, 103

– Goniocidaris (Discocidaris) peltata 94, 103, 104 – Goniocidaris (Discocidaris) 94 – Goniocidaris (Goniocidaris) impressa 101, 102, 106 – Goniocidaris (Goniocidaris) tubaria 94, 106, 107 – Goniocidaris (Goniocidaris) umbraculum 94, 98, 106, 107, 108 – Goniocidaris (Petalocidaris) balinensis 95, 96 – Goniocidaris (Petalocidaris) biserialis 94, 95, 96 – Goniocidaris (Petalocidaris) florigera 94, 98, 100 – Goniocidaris (Petalocidaris) spinosa 94, 104, 105 – Goniocidaris (Petalocidaris) 94 – Goniocidaris alba 94 – Goniocidaris corona 94, 98, 99, 108 – Goniocidaris magi 94, 101 – Goniocidaris umbraculum 13 – Goniocidaris, Goniocidaris impressa 101, 102, 106 Goniodiadema 21, 167, 186 – Goniodiadema mauritiensis 186 Goniopneustes 333 – Goniopneustes pentagonus 333, 334 gracile, Calverisoma 150, 151 Gracilechinus 22, 274, 281, 289 – Gracilechinus acutus 281, 282, 283 – Gracilechinus acutus flemingi 284 – Gracilechinus acutus mediterranea 284 – Gracilechinus acutus norvegicus 282 – Gracilechinus affinis 281, 282, 283, 285 – Gracilechinus alexandri 281, 282, 283, 286 – Gracilechinus atlanticus 281, 284, 286 – Gracilechinus elegans 4, 276, 281, 284, 285, 287 – Gracilechinus gracilis 281, 286, 287 – Gracilechinus lucidus 281, 288 – Gracilechinus stenoporus 282, 288, 289 gracilis, Gracilechinus 281, 286, 287 gracilis, Rhopalocidaris 110, 111 grandis, Amblypneustes 222 grandis, Stereocidaris 115, 116, 117, 120 granularis var. rubra, Stereocidaris 117, 118 granularis, Sphaerechinus 9, 277, 337, 350 granularis, Stereocidaris 115, 117, 118, 126 granulatus, Coelopleurus 209, 212 gratilla, Tripneustes 9, 353, 356, 357 gratiosa, Parasalenia 219, 220 gratulatum, Chaetodiadema 173, 174, 175 gravieri, Nudechinus 344, 346 grimaldii, Sperosoma 153, 154, 155 grossularia, Pseudechinus 242, 243 Gymnechinus 22, 333, 335, 344 – Gymnechinus abnormalis 335 – Gymnechinus epistichus 335, 337 – Gymnechinus pulchellus 335, 337 – Gymnechinus robillardi 335, 337 Habrocidaris 22, 203, 215 – Habrocidaris argentea 215, 216 – Habrocidaris scutata 215, 216 Hapalosoma 21, 139, 150 – Hapalosoma amynina 150 – Hapalosoma gemmiferum 150, 151

 379

380 

 Index

– Hapalosoma pellucidum 150, 151 – Hapalosoma pulchrum 150, 151 Hardouinia mortonis 17 hardwickii, Temnopleurus 251, 253, 254 hastata, Notocidaris 85, 86, 87 hastigera, Acanthocidaris 25, 27, 28 hastigera, Salenocidaris 195 hawaiensis, Caenopedina 190, 191, 192 hawaiiense, Aspidodiadema 162, 164, 165 hawaiiense, Temnotrema 258, 260 hawaiiensis, Prionocidaris 51, 56, 58 hawaiiensis, Stereocidaris 115, 117, 121 Heliocidaris 22, 294, 306 – Heliocidaris australiae 306, 307 – Heliocidaris bajulus 306, 307, 308 – Heliocidaris crassispina 306, 308, 327 – Heliocidaris erythrogramma var. armigera 309, 310 – Heliocidaris erythrogramma 13 – Heliocidaris erythrogramma 306, 309, 310, 311 – Heliocidaris robertsi 306, 311 – Heliocidaris tuberculata 306, 311, 312 Hemicentrotus 22, 324 – Hemicentrotus pulcherrimus 324, 325 Hemiphormosoma 21, 135, 138 – Hemiphormosoma paucispinum 137, 138 Hemipneustes striatoradiatus 18 Hesperocidaris 21, 23, 39 – Hesperocidaris asteriscus 40, 41 – Hesperocidaris dubia 40, 41 – Hesperocidaris houstoniana 40, 42 – Hesperocidaris panamensis 40, 42 – Hesperocidaris perplexa 40, 41, 42 hesperus, Pseudechinus 242, 243 Heterocentrotus 22, 291, 294, 311, 316 – Heterocentrotus mamillatus 311, 312, 314 – Heterocentrotus trigonarius 311, 314, 315 hirsutispina, Rhopalocidaris 111 hispidum, Tromikosoma 155, 156, 157 Histocidaridae 21, 23, 126 Histocidaris 21, 126, 131 – Histocidaris acutispina 127 – Histocidaris australiae 127, 128 – Histocidaris carinata 127, 128 – Histocidaris cobosi 127, 129 – Histocidaris crassispina 127, 129 – Histocidaris denticulata 127, 128, 129 – Histocidaris elegans 127, 129, 130 – Histocidaris formosa 127, 129, 130 – Histocidaris longicollis 127, 130 – Histocidaris magnifica 127, 130, 131 – Histocidaris misakiensis 127, 129 – Histocidaris nuttingi 127, 131 – Histocidaris purpurata 126 – Histocidaris purpurata 127, 131, 132 – Histocidaris recurvata 127, 132 – Histocidaris sharreri 127, 133 – Histocidaris variabilis 127, 133 Histocidaroidea 23 Holasteroida 16, 17 Holectypoida 16

Holopneustes 22, 221, 222, 226 – Holopneustes inflatus 227, 228 – Holopneustes porosissimus 222, 227, 229 – Holopneustes purpurascens 227, 229, 230 Holothuroidea 1 Homalocidaris 21, 74, 84 – Homalocidaris gigantea, 81, 84, 85 hoplacantha, Hygrosoma 152 horridum, Plesiodiadema 160, 161, 162 horridus, Dermechinus 274, 275 houstoniana, Hesperocidaris 40, 42 humilis, Clypeaster 11, huttoni, Pseudechinus 242, 243 Hyattechinus pentagonus 15 Hygrosoma 21, 139, 151 – Hygrosoma hoplacantha 152 – Hygrosoma luculentum 142 – Hygrosoma luculentum 152 – Hygrosoma petersii 152, 153 Hypsiechinus 22, 220, 264, 265 – Hypsiechinus coronatus 265, 267 hystrix, Calveriosoma 142, 150, 151 ijimai, Asthenosoma 147, 148 imperialis, Phyllacanthus 45, 47, 49, 50 impressa, Goniocidaris 101, 102, 106 impressus, Printechinus 240, 241 incerta, Aporocidaris 13, 74, 78, 79, 80 incerta, Porocidaris 76 inconspicuus, Nudechinus 344 incrassata, Salenocidaris 195 indiana, Pseudoboletia 347, 348, 349 indica, Caenopedina 190, 191, 193 indica, Goniocidaris 94, 101, 102 indica, Stereocidaris 115, 118, 119, 126 indica, Trigonocidaris 270 indicum, Plesiodiadema 159, 160, 162, 163 inflatus, Holopneustes 227, 228 ingolfiana, Stereocidaris 115, 119 insularis, Echinometra 298 intermedium, Aspidodiadema 162, 165 intermedium, Asthenosoma 147 intermedius, Strongylocentrotus 328, 331 interruptus, Coelopleurus 209, 213 Irregularia 4, 9, 10, 14, 16, 157 irregularis, Phyllacanthus 45, 47, 49 jacobyi, Aspidodiadema 162, 165 japonica, Fibularia 12 japonica, Phalacrocidaris 114, 115 japonicum, Chaetodiadema 173, 174, 175 jeanneti, Paracidaris 15 Kamptosoma 21, 135, 136 – Kamptosoma abyssale 136 – Kamptosoma asterias 135, 136, 137 Kamptosomatidae 21, 135, 136 keiense, Chaetodiadema 173, 174, 176 keiensis, Microcyphus 232, 234, 235 kellersi, Zenocentrotus 316, 317

Index 

Kionocidaris 21, 23, 42 – Kionocidaris striata 43, 45 koehleri, Tromikosoma 156 laevigata, Stylocidaris 59, 67, 68 Lamprechinus 264 lanceolata, Notocidaris 85, 86, 87 Leiopedina 189 Lepidesthes wortheni 15 leppienae, Araeosoma 136, 140, 142 leptaleum, Araeosoma 140, 143, 144 Leptodiadema purpureum 187 leucacantha, Stereocidaris 115, 120, 121 leucoglobus, Amblypneustes 222, 223, 224 lineata, Stylocidaris 59, 67, 68 Lissocidaris 21, 23, 43 – Lissocidaris fusca 43, 45 – Lissocidaris xanthe 43, 45 Lissodiadema 21, 163, 167, 187 – Lissodiadema lorioli 21, 187 lividus, Paracentrotus 277, 319, 321, 328, 351 lixula, Arbacia 203, 204, 205 longicollis, Coelpleurus 209, 210, 213 longicollis, Histocidaris 127, 130 longispina, Ctenocidaris nutrix 81 longispinus, Centrostephanus 169, 170, 171, 173 longispinus, Phyllacanthus 45, 47, 49 lorioli, Amphipneustes 18 lorioli, Austrocidaris 91, 93 lorioli, Lissodiadema 187 lorioli, Stylocidaris 59, 67, 68 Lovenia elongata 11 Loxechinus 22, 316 – Loxechinus albus 294, 316, 318, 319 lucidus, Gracilechinus 281, 288 luculentum, Hygrosoma 142, 152 lucunter, Echinometra 298 Lytechinus 22, 333, 335, 337 – Lytechinus anamesus 337, 340 – Lytechinus callipeplus 337, 338 – Lytechinus euerces 337, 338 – Lytechinus panamensis 337, 338, 339 – Lytechinus pictus 337, 339, 340 – Lytechinus semituberculatus 337, 340, 341 – Lytechinus variegatus carolinus 340, 341 – Lytechinus variegatus pallidus 340 – Lytechinus variegatus variegatus 340 – Lytechinus variegatus 4, 337, 340, 341, 342, 343, 358 – Lytechinus williamsi 337, 341, 343 maculata, Genocidaris 265, 266 maculata, Pseudoboletia 7, 334, 347, 349 maculatum, Temnotrema 258, 260 maculatus, Coelopleurus 209, 213, 214 maculatus, Microcyphus 232, 234, 236 maculatus, Toxopneustes 351, 352 maculicollis, Acanthocidaris 25, 27, 28 maculosa, Stylocidaris 59, 68, 69 magellanicus, Pseudechinus 242, 243, 244, 318 magi, Goniocidaris 94, 101

magnifica, Astropyga 167, 168 magnifica, Histocidaris 127, 130, 131 magnificus, Phyllacanthus 45, 47 maillardi, Coelopleurus 209, 213, 214 malayanus var. Centrostephanus asteriscus 169 mamillatus, Heterocentrotus 311, 312, 314 marionis, Pseudechinus 242, 244 marisrubri, Asthenosoma 147, 148, 149 marsupialis, Amphipneustes 13 mathaei, Echinometra 14 mathei, Echinometra 220, 298, 299, 300, 301 mauritiensis, Goniodiadema 186 mediterranea, Gracilechinus acutus 284 meijerei, Aspidodiadema 160, 162, 164 melo, Echinus 276, 279, 280 mertensii, Colobocentrotus 295, 296 Mesocentrotus 22, 324, 325, 326, 329 – Mesocentrotus franciscanus 325, 326 – Mesocentrotus nudus 309, 326, 327 Mespilia 22, 221, 230 – Mespilia globulus 230, 231, 232, 356 Metalia spatagus 1, 9 metularia, Eucidaris 35, 37, 38, 47 mexicanum, Diadema 177, 178, 179, 180 micans, Calocidaris 28 michaelseni, Temnopleurus 251, 253, 255 Microcyphus 22, 221, 232 – Microcyphus zigzag 232, 235, 238 – Microcyphus annulatus 232, 235 – Microcyphus ceylanicus 232 – Microcyphus compsus 232, 234, 235 – Microcyphus excentricus 232, 234 – Microcyphus keiensis 232, 234, 235 – Microcyphus maculatus 232, 234, 236 – Microcyphus olivaceus 232, 234 – Microcyphus pulchellus 232, 235 – Microcyphus rousseaui 232, 236, 237 micropora, Trigonocidaris 270, 271, 273 Micropyga 22, 187 – Micropyga tuberculata 187, 188 – Micropyga violacea 187, 189 Micropygidae 22, 187 Micropygoida 22, 159, 163, 187 microtuberculata, Plesiodiadema 160, 162 microtuberculata, Stereocidaris 115, 120, 121, 126 microtuberculatus, Psammechinus 319, 321, 323, 324 migratum, Araeosoma 140, 144 mikado, Goniocidaris 94, 102, 103 miliaris, Psammechinus 282, 319, 321, 323, 324, 328 miliaris, Salenocidaris 195, 196, 197 milleri, Aporocidaris 74, 77, 78 Miocidaridae 14 mirabilis, Caenopedina 190, 191, 193 mirabilis, Chaenopedina 159 mirabilis, Echinophyces (Parasite) 76 mirabilis, Phymechinus 16 misakiensis, Histocidaris 127, 129 molaris, Echinostrephus 302, 304 molle, Plesiodiadema 160, 162, 163 monolini, Trigonocidaris 270, 272

 381

382 

 Index

Monophoraster darwini 18 Monostychia australis 18 montanum, Aspidodiadema 162, 165 mortensen, Antrechinus 13 mortenseni, Notocidaris 85, 86, 87, 88 mortonia, Hardouinia 17 multicolor, Nudechinus 344 multidentatus, Echinus 276, 279, 280 nascaensis, Stereocidaris 115, 120, 121 neumayeri, Sterechinus 14, 290, 291, 293 nicobaricum, Aspidodiadema 160, 162, 165, 166 niger, Tetrapygus 218 nitidus, Centrostaphanus 169, 171 nitidus, Trigonocidaris 270, 271, 272 norvegicus, Gracilechinus acutus 282 notius, Pseudechinus 242, 244 Notocidaris 21, 74, 85 – Notocidaris gaussensis 85, 86 – Notocidaris hastata 85, 86, 87 – Notocidaris lanceolata 85, 86, 87 – Notocidaris mortenseni 85, 86, 87, 88 – Notocidaris platyacantha 85, 86, 87, 89 – Notocidaris remigera 85, 86, 87, 89 – Notocidaris sp. 85, 87, 89 novaezealandiae, Caenopedina 190, 192 novaezealandiae, Pseudechinus 242, 244, 245 nuda, Cidaris 31, 34 Nudechinus 22, 333, 343 – Nudechinus ambonensis 344, 345 – Nudechinus darnleyensis 344, 345 – Nudechinus gravieri 344, 346 – Nudechinus inconspicuus 344 – Nudechinus multicolor 344 – Nudechinus rubripunctata 344 – Nudechinus scotiopremnus 344, 345, 346, 347 – Nudechinus stictus 344, 346 – Nudechinus verruculatus 344, 346, 347 nudispina, Salenocidaris 196 nudum, Sperosoma 154 nudus, Mesocentrotus 309, 326, 327 nudus, Strongylocentrotus 325 nutrix, (Eurocidaris), Ctenocidaris 81 nutrix, Ctenocidaris 80, 82 nuttingi, Histocidaris 127, 131 oblonga, Echinometra 298, 301 obscurum Sperosoma 154, 156 occidentalis Pseudoboletia 347, 350 Ogmocidaris 21, 91, 108 – Ogmocidaris benhami 108, 109 oligopora, Salmaciella 245, 247 olivaceus, Microcyphus 232, 234 Opechinus 22, 221, 238 – Opechinus albus 238, 239 – Opechinus variabilis 238, 239 Ophiuroidea 1 Orechinus 264 ornata, Podocidaris 216

oshimai, Psychocidaris 134 otagoensis, Caenopedina 190, 194 ovum, Amblypneustes 222, 223, 225 owstoni, Araeosoma 141, 144, 145 Pachechinus 306 – Pachechinus australiae 306 – Pachechinus bajulus 306, 307 Pachycentrotus 306 – Pachycentrotus bajulus 306, 307, 324 pacifica, Salenocidaris 196, 197 pallescens, Temnotrema 258, 259 pallidum, Chaetodiadema 159, 173, 174, 176, 177 pallidus, Amblypneustes 222, 223, 225 pallidus, Lytechinus variegatus 340 pallidus, Strongylocentrotus 328, 331 palmeri, Diadema 167, 177, 178, 179, 180 panamense, Tromikosoma 156 panamensis, Hesperocidaris 40, 42 panamensis, Lytechinus 337, 338, 339 Paracentrotus 22, 316, 319 – Paracentrotus gaimardi 319, 321 – Paracentrotus lividus 277, 319, 321, 328, 351 Paracidaris jeanneti 15 paradoxus, Zenocentrotus 316, 317 Paraphormosoma 21, 138 – Paraphormosoma alternans 137, 138 Parasalenia 22, 219, 300 – Parasalenia gratiosa 219, 220 Parasaleniidae 22, 219, 220 Parasalenis poehlii 219, 220 parasol, Goniocidaris 94, 103, 108 Paratrema 22, 221, 238 – Paratrema doederleini 238, 239, 240 Parechinidae 22, 274, 316 Parechinus 22, 316 – Parechinus angulosus 4, 319, 321, 322 parvispinus, Phyllacanthus 45, 49, 50 parviungulatum, Araeosoma 141, 144 pattersoni, Salenia 196 paucispinum, Araosoma 141, 144, 145 paucispinum, Diadema 177, 178, 181 paucispinum, Hemiphormosoma 137, 138 pawsoni, Austrocidaris 91, 93 pedifer, Colobocentrotus (Podophora)  296, 297 Pedinidae 22, 189 Pedinoida 22, 159, 189 pellucidum, Hapalosoma 150, 151 peltata, Goniocidaris 94, 103, 104 pentagonus, Goniopneustes 333, 334 pentagonus, Hyattechinus 15 periculosum, Asthenosoma 147, 148 perplexa, Hesperocidaris 40, 41, 42 perrieri, Ctenocidaris 76, 80, 81, 82, 83 Petalocidaris 94 – Petalocidaris, Goniocidaris balinensis 95, 96 – Petalocidaris, Goniocidaris biserialis 94, 95, 96

Index 

– Petalocidaris, Goniocidaris florigera 94, 98, 100 – Petalocidaris, Goniocidaris spinosa 94, 104, 105 petersii, Hygrosoma 152, 153 Phalacrocidaris 21, 114 – Phalacrocidaris japonica 114, 115 phoenissa, Temnotrema 258, 260, 261 phoinissa, Bathysalenia 198, 200 Phormosoma 21, 135, 138, 139 – Phormosoma adenicum 139 – Phormosoma bursarium 136, 138, 140 – Phormosoma placenta var. africana 139 – Phormosoma placenta 138, 139, 140 – Phormosoma rigidum 138, 139 – Phormosoma verticillatum 138, 139, 140 Phormosomatidae 21, 135, 136 Phyllacantus 21, 23, 45 – Phyllacanthus imperialis 45, 47, 49, 50 – Phyllacanthus irregularis 45, 47, 49 – Phyllacanthus longispinus 45, 47, 49 – Phyllacanthus magnificus 45, 47 – Phyllacanthus parvispinus 45, 49, 50 – Phyllacantus dubius 45, 46 – Phyllacathus forcipulatus 45, 46 Phymechinus mirabilis 16 pictus, Lytechinus 337, 339, 340 pileolus, Toxopneustes 334, 348, 351, 352, 354, 355 Pimelometopon pulchrum (Pisces) 170 pistillaris, Prionocidaris 51, 52, 56, 58 placenta var. africana, Phormosoma 139 placenta, Phormosoma 138, 139, 140 platyacantha, Notocidaris 85, 86, 87, 89 Plesiodiadema 21, 159 – Plesiodiadema amphigymnum 160, 162 – Plesiodiadema antillarum 160, 161, 162 – Plesiodiadema globulosum 160, 161, 162 – Plesiodiadema horridum 160, 161, 162 – Plesiodiadema indicum 159, 160, 162, 163 – Plesiodiadema microtuberculata 160, 162 – Plesiodiadema molle 160, 162, 163 Plococidaris 21, 23, 51 – Plococidaris verticillata 47, 50, 51 plotii, Clypeus 17 Podocidaris 22, 203, 216 – Podocidaris ornata 216 – Podocidaris sculpta 216 – Podocidaris sibogae 216 Podophora 22, 291, 294, 295, 316 – Podophora, Colobocentrotus atratus 295,296 – Podophora, Colobocentrotus pedifer 296, 297 poehlii, Parasalenia 219, 220 polyacanthus, Strongylocentrotus 328, 331, 332 Polyechinus 22, 274, 289 – Polyechinus agulhensis 289 polyplax, Ctenocidaris 80 popiae, Prionocidaris 51, 58 Poriocidaris 126, 131 – Poriocidaris purpurata 126, 131 Porocidaris incerta 76 porosissimus, Holopneustes 222, 227, 229 porphyrogigas, Caenopedina 190, 194

Printechinus 22, 221, 239 – Printechinus impressus 240, 241 – Printechinus viridis 240, 241 Prionechinus 22, 264, 268 – Prionechinus agassizi 268, 269 – Prionechinus forbesianus 268, 269 – Prionechinus sagittiger 268, 269 – Prionechinus sculptus 268, 270, 271 prionigera, Pygmaeocidaris 216 Prionocidaris 21, 25, 38, 51 – Prionocidaris australis 51, 52, 53 – Prionocidaris baculosa annulifera 52 – Prionocidaris baculosa 47, 51, 52, 54 – Prionocidaris bispinosa 51, 52, 53, 55 – Prionocidaris callista 51, 52, 55, 56 – Prionocidaris glandulosa 51, 56 – Prionocidaris hawaiiensis 51, 56, 58 – Prionocidaris pistillaris 51, 52, 56, 58 – Prionocidaris popiae 51, 58 – Prionocidaris thomasi 51, 56, 58 profundi, Salenocidaris 196, 197 Psammechinus 22, 316, 321 – Psammechinus microtuberculatus 319, 321, 323, 324 – Psammechinus miliaris 282, 319, 321, 323, 324, 328 Pseudechinus 22, 221, 241 – Pseudechinus albocinctus 242 – Pseudechinus flemingi 242, 243 – Pseudechinus grossularia 242, 243 – Pseudechinus hesperus 242, 243 – Pseudechinus huttoni 242, 243 – Pseudechinus magellanicus 242, 243, 244, 318 – Pseudechinus marionis 242, 244 – Pseudechinus notius 242, 244 – Pseudechinus novaezealandiae 242, 244, 245 – Pseudechinus sanctipauli 242, 245 – Pseudechinus variegatus 242, 245 Pseudoboletia 22, 333, 337, 347 – Pseudoboletia atlantica 347, 348 – Pseudoboletia indiana 347, 348, 349 – Pseudoboletia maculata 7, 334, 347, 349 – Pseudoboletia occidentalis 347, 350 Pseudocentrotus 22, 324, 327 – Pseudocentrotus depressus 327, 328 Psilocidaris 21, 91, 108 – Psilocidaris echinulata 108, 110 Psychocidaridae 21, 23, 133 Psychocidaris 21, 134 – Psychocidaris oshimai 134 pulchella, Caenopedina 190, 195 pulchellum, Temnotrema 258, 260 pulchellus, Amblypneustes 222, 223 pulchellus, Gymnechinus 335, 337 pulchellus, Microcyphus 232, 235 pulchellus, Strongylocentrotus 328, 331 pulcherrimus, Hemicentrotus 324, 325 pulchrum, Hapalosoma 150, 151 pulchrum, Pimelometopon (Pisces) 170 pulvinata, Astropyga 167, 168, 169 punctulata, Arbacia 203, 204, 206 purpurascens, Holopneustes 227, 229, 230

 383

384 

 Index

purpurascens, Stereocidaris 115, 122, 126 purpurata, Histocidaris 126, 127, 131, 132 purpurata, Poriocidaris 126, 131 purpuratus, Strongylocentrotus 331, 332, 333 purpureum, leptodiadema 187 Pygasteroida 16 Pygmaeocidaris 22, 203, 216 – Pygmaeocidaris prionigera 216 pyrsacantha, Compsocidaris 35, 36, 117 quincunciale, Sperosoma 154 radiata, Astropyga 167, 168, 169, 188 radiata, Trigonocidaris 270, 272 recurvata, Histocidaris 127, 132 reducta, Stereocidaris 115, 122, 123 reevesii, Temnopleurus 251, 255, 256 reini, Stylocidaris 59, 69, 70 remigera, Notocidaris 85, 86, 87, 89 reticulatum, Temnotrema 258, 261 Rhopalocidaris 21, 91, 110 – Rhopalocidaris gracilis 110, 111 – Rhopalocidaris hirsutispina var. viridis 111 – Rhopalocidaris hirsutispina, 111 – Rhopalocidaris rosea 110, 111 Rhynchocidaris 21, 74, 88, 91 – Rhynchocidaris triplopora 75, 88, 90, 91 rigidum, Phormosoma 138, 139 robertsi, Heliocidaris 306, 311 robillardi, Gymnechinus 335, 337 rodgersii, Centrostephanus 159, 169, 172, 173, 311 rosea, Rhopalocidaris 110, 111 roseoviridis, Salmacis 248, 250 roseus, Toxopneustes 351, 353, 355 rousseaui, Microcyphus 232, 236, 237 rubricingulus, Centrostephanus 169, 173 rubripunctata, Nudechinus 344 rubrum, Temnotrema 258, 261, 262 rufa, Cypraecassis (Mollusca) 10 rufa, Stylocidaris 59, 69, 70 rufus, Desmechinus 265 rugosa, Cidaris 31, 34, 35 rugosa, Ctenocidaris 80, 82, 83 ryukyuensis, Stylocidaris 59, 69, 70 sagittiger, Prionechinus 268, 269 Salanocidaris nudispina 196 Salanocidaris profundi 196, 197 Salanocidaris varispina 196, 197, 198 Salenia pattersoni 196 Saleniidae 22, 195 Salenioida 22, 195 Salenocidaris 22, 195 – Salenocidaris brachygnata 195 – Salenocidaris crassispina 195 – Salenocidaris hastigera 195 – Salenocidaris incrassata 195 – Salenocidaris miliaris 195, 196, 197 – Salenocidaris pacifica 196, 197 – Salenocidaris varispina 195

Salmaciella 22, 221, 245 – Salmaciella dussumieri 245, 246 – Salmaciella erythracis 245, 246 – Salmaciella oligopora 245, 247 Salmacis 22, 221, 246, 247 – Salmacis belli 248, 249 – Salmacis bicolor 248, 249 – Salmacis roseoviridis 248, 250 – Salmacis sphaeroides 221, 248, 250, 251 – Salmacis virgulata 248, 250, 251 sanctipauli, Pseudechinus 242, 245 savignyi, Diadema 177, 178, 181, 182, 183 sceptrifera, Stereocidaris 15 sceptriferoides, Stereocidaris 115, 123, 124, 126 Schizasteridae 13 Schizocidaris 21, 91, 112 – Schizocidaris assimilis 112, 113 – Schizocidaris fasciata 112 – Schizocidaris serrata 112, 113 scillae, Temnotrema 258, 262 scotiopremnus, Nudechinus 344, 345, 346, 347 scrippsae, Bathysalenia 198, 200 sculpta, Bathysalenia 198, 200, 201 sculpta, Podocidaris 216 sculptum, Temnotrema 258, 262, 263 sculptus, Prionechinus 268, 270, 271 sculptus, Trigonocidaris 270, 273 scutata, Habrocidaris 215, 216 Selenechinus 22, 294, 315 – Selenechinus armatus 315 semituberculatus, Lytechinus 337, 340, 341 serrata, Schizocidaris 112, 113 setosum, Diadema 167, 177, 178, 181, 182, 183 sharreri, Histocidaris 127, 133 siamense, Temnotrema 258, 263 sibogae, Goniocidaris 94, 98, 104, 105 sibogae, Podocidaris 216 silviae, Centrostaphanus 169, 173 sinuosum, Aspidodiadema 162, 166 sp., Ctenocidaris 74 sp., Notocidaris 85, 87, 89 spatagus, Metalia 1, 9 Spatangoida 3, 10, 17 spatuligera, Arbacia 204, 207, 208 speciosa, Ctenocidaris 76, 80, 82, 83 spectabilis, Erbechinus 224, 226 Sperosoma 21, 140, 153 – Sperosoma antillense 154 – Sperosoma armatum 154 – Sperosoma biseriatum 154, 155 – Sperosoma crassispinum 154, 156 – Sperosoma durum 154 – Sperosoma giganteum 154 – Sperosoma grimaldii 153, 154, 155 – Sperosoma nudum 154 – Sperosoma obscurum 154, 156 – Sperosoma quincunciale 154 – Sperosoma tristichum 154, 155, 156

Index 

Sphaerechinus 22, 33, 350 – Sphaerechinus granularis 277, 337, 350 – Sphaerechinus granularis 9 sphaeroides, Salmacis 221, 248, 250, 251 spinosa, Ctenocidaris 81, 82, 83, 84 spinosa, Goniocidaris 94, 104, 105 spinosa, Tretocidaris 72, 73 spinulosa, Austrocidaris 91, 92, 93 splendens, Araeosoma 141, 144 squamosa, Stereocidaris 115, 123 Stylocidaris conferta 59, 65, 66 stellata, Arbacia 204, 207, 209 stenoporus, Gracilechinus 282, 288, 289 Sterechinus 22, 274, 290 – Sterechinus agassizii 290, 292 – Sterechinus antarcticus 290, 291, 292 – Sterechinus bernasconiae 290, 291 – Sterechinus dentifer 290, 291 – Sterechinus diadema 290, 291, 293 – Sterechinus neumayeri 14, 290, 291, 293 Stereocidarinae 21, 23, 113 Stereocidaris 21, 114, 126 – Stereocidaris alcocki 114, 115 – Stereocidaris capensis 114, 115 – Stereocidaris excavata 115, 116 – Stereocidaris grandis 115, 116, 117, 120 – Stereocidaris granularis var. rubra 117, 118 – Stereocidaris granularis 115, 117, 118, 126 – Stereocidaris hawaiiensis 115, 117, 121 – Stereocidaris indica 115, 118, 119, 126 – Stereocidaris ingolfiana 115, 119 – Stereocidaris leucacantha 115, 120, 121 – Stereocidaris microtuberculata 115, 120, 121, 126 – Stereocidaris nascaensis 115, 120, 121 – Stereocidaris purpurascens 115, 122, 126 – Stereocidaris reducta 115, 122, 123 – Stereocidaris sceptriferoides 15, 115, 123, 124, 126 – Stereocidaris squamosa 115, 123 – Stereocidaris stylifera 115, 124, 125, 126 – Stereocidaris sulcatispinis 115, 125, 126 – Stereocidaris tubifera 115, 126, 126 stictus, Nudechinus 344 Stirechinus 22, 274, 291 – Stirechinus tylodes 291, 293 Stomopneustes 22, 201 – Stomopneustes variolaris 201, 202 Stomopneustidae 22, 201 Stomopneustoida 22, 201 striata, Kionocidaris 43, 45 striatoradiatus Hemipneustes 18 Strongylocentrotidae 22, 274, 324, 328 Strongylocentrotus 22, 324, 326, 328, 329 – Strongylocentrotus djakonovi 328 – Strongylocentrotus droebachiensis 328, 329 – Strongylocentrotus fragilis 328, 329, 330 – Strongylocentrotus franciscanus 325 – Strongylocentrotus intermedius 328, 331 – Strongylocentrotus nudus 325 – Strongylocentrotus pallidus 328, 331 – Strongylocentrotus polyacanthus 328, 332, 332

– Strongylocentrotus pulchellus 328, 331 – Strongylocentrotus purpuratus 331, 332, 333 stylifera, Stereocidaris 115, 124, 125, 126 Stylocidaris 21, 25, 39, 58 – Stylocidaris affinis 34, 58, 60 – Stylocidaris albidens 58, 60 – Stylocidaris amboina 58, 61 – Stylocidaris annulosa 58, 61 – Stylocidaris badia 58, 62, 63 – Stylocidaris bracteata 59, 62, 63 – Stylocidaris brevicollis 59, 62, 64 – Stylocidaris calacantha 59, 64 – Stylocidaris cingulata 59, 64 – Stylocidaris effluens 59, 65, 66 – Stylocidaris fusispina 59, 65 – Stylocidaris laevigata 59, 67, 68 – Stylocidaris lineata 59, 67, 68 – Stylocidaris lorioli 59, 67, 68 – Stylocidaris maculosa 59, 68, 69 – Stylocidaris reini 59, 69, 70 – Stylocidaris rufa 59, 69, 70 – Stylocidaris ryukyuensis 59, 69, 70 – Stylocidaris tiara 59, 70 sulcatispinis, Stereocidaris 115, 125, 126 superba, Caenopedina 190, 195 Temnechinus 220 Temnopleuridae 22, 201, 220, 221 Temnopleuroida 16 Temnopleurus 22, 221, 247, 250, 257 – Temnopleurus alexandri 251, 252, 255 – Temnopleurus apodus 251, 252, 253 – Temnopleurus decipiens 251, 252, 253 – Temnopleurus hardwickii 251, 253, 254 – Temnopleurus michaelseni 251, 253, 255 – Temnopleurus reevesii 251, 255, 256 – Temnopleurus toreumaticus 221, 251, 253, 255, 256, 257 Temnotrema 22, 221, 224, 239, 256, 257 – Temnotrema bothryoides 257, 258, 259 – Temnotrema elegans 258, 259 – Temnotrema hawaiiense 258, 260 – Temnotrema maculatum 258, 260 – Temnotrema pallescens 258, 259 – Temnotrema phoenissa 258, 260 – Temnotrema pulchellum 258, 260, 261 – Temnotrema reticulatum 258, 261 – Temnotrema rubrum 258, 261, 262 – Temnotrema scillae 258, 262 – Temnotrema sculptum 258, 262, 263 – Temnotrema siamense 258, 263 – Temnotrema xishaensis 258, 264 tenue, Tromikosoma 156 tenuispina, Goniocidaris 94, 105, 106 tenuispinus, Centrostaphanus 169, 172, 173 tenuispinus, Echinus 276, 280 tertii, Araeosoma 141, 144 tesselatum, Araeosoma 141, 144, 146 Tetrapygus niger 218 Tetrapygus 22, 203, 218

 385

386 

 Index

thetidis, Araeosoma 136, 141, 145, 146 thomasi, Prionocidaris 51, 56, 58 thouarsi, Eucidaris 11 thouarsii, Eucidaris 35, 38, 39 tiara, Stylocidaris 59, 70, 72 tonsum, Aspidodiadema 162, 166 toreumaticus, Temnopleurus 221, 251, 253, 255, 256, 257 Toxopneustes 22, 333, 337, 351 – Toxopneustes elegans 351, 352 – Toxopneustes maculatus 351, 352 – Toxopneustes pileolus 334, 348, 351, 352, 354, 355 – Toxopneustes roseus 351, 353, 355 Toxopneustidae 10, 22, 274, 328, 333 Tretocidaris 21, 25, 72 – Tretocidaris bartletti 72, 73 – Tretocidaris spinosa 72, 73 Triadocidaridae 14 tribuloides, Eucidaris 35, 38, 39 trigonarius, Heterocentrotus 311, 314, 315 Trigonocidaridae 22, 220, 263, 264 Trigonocidaris 22, 264, 270 – Trigonocidaris albida 270, 271 – Trigonocidaris albidoides 263, 270 – Trigonocidaris indica 270 – Trigonocidaris micropora 270, 271, 273 – Trigonocidaris monolini 270, 272 – Trigonocidaris nitidus 270, 271, 272 – Trigonocidaris radiata 270, 272 – Trigonocidaris sculptus 270, 273 – Trigonocidaris tuberculata 270 – Trigonocidaris versicolor 270, 273 triplopora, Rhynchocidaris 75 triplopora, Rhynchocidarsi 88, 90, 91 Tripneustes 22, 333, 337, 351, 353 – Tripneustes depressus 353, 356 – Tripneustes gratilla elatensis 356, 358 – Tripneustes gratilla 9, 353, 356, 357 – Tripneustes ventricosus 4, 341, 353, 357, 358 tristichum, Sperosoma 154, 155, 156 Tromikosoma 21, 135, 140, 155 – Tromikosoma australe 155, 156 – Tromikosoma hispidum 155, 156, 157 – Tromikosoma koehleri 156 – Tromikosoma panamense 156 – Tromikosoma tenue 156 – Tromikosoma uranus 156, 157 tubaria, Goniocidaris 94, 106, 107 tuberculata, Heliocidaris 306, 311, 312 tuberculata, Micropyga 187, 188

tuberculata, Trigonocidaris 270 tuberculatum, Chaetodiadema 173, 174, 177 tubifera, Stereocidaris 115, 126 Tylocidaris 134 tylodes, Echinus 276, 281 tylodes, Stirechinus 291, 293 umbraculum, Goniocidaris 13, 94, 98, 106, 107, 108 undulatus, Coelopleurus 209, 213, 215 unicolor, Bathysalenia 198, 200, 201 uranus, Tromikosoma 156, 157 Urechinidae 13 usarpi, Aporocidaris 74, 75, 78 vanbrunti, Echinometra 298, 301, 302, 303 variabilis, Histocidaris 127, 133 variabilis, Opechinus 238, 239 variegatus, Lytechinus 4, 337, 340, 341, 342, 343, 358 – variegatus, Lytechinus variegatus 340 variegatus, Pseudechinus 242, 245 variolaris, Stomopneustes 201, 202 varispina, Salenocidaris 195, 196, 197, 198 varium, Asthenosoma 136, 142, 147, 148, 149 ventricosus, Tripneustes 4, 341, 353, 357, 358 verruculatus, Cyrtechinus 346 verruculatus, Nudechinus 344, 346, 347 versicolor, Desmechinus 265, 266 versicolor, Trigonocidaris 270, 273 verticillata, Plococidaris 47, 50, 51 verticillatum, Phormosoma 138, 139, 140 violacea, Micropyga 187, 189 violaceum, Araeosoma 136, 141, 146 virgulata, Salmacis 248, 250, 251 viridis var., Rhopalocidaris hirsutispina 111 viridis, Echinometra 298, 302, 303 viridis, Printechinus 240, 241 vittatus, Coelopleurus 209, 214 wallisi, Echinus 276, 281 williamsi, Lytechinus 337, 341, 343 wortheni, Lepidesthes 15 xanthe, Lissocidaris 43, 45 xishaensis, Temnotrema 258, 264 Zenocentrotus 22, 291, 294, 315 – Zenocentrotus paradoxus 316, 317 – Zentrocentrotus kellersi 316, 317 zigzag, Microcyphus 232, 235, 238