Sea Urchins

Updated 12/20/2022

Phylum Echinodermata, Class Echinoidea

Sea Urchins

Sea Urchins have radially symmetrical bodies divided into 5 equal parts. They move about using articulating spines and tube feet. Jawed tube feet called pedicellariae are employed for defense along with sometimes venomous spines. Urchins feed upon algae, sponge, or detritus. Their hard jaws and stout spines are capable of eroding coral or rock in some species. Urchin roe is a delicacy in Japan and supports a fishery in the North Pacific.

For more information about sea urchins visit The Echinoid Directory.

Tube Feet	Mouth

HAWAII - ENDEMIC

Actinocidaris thomasi

THOMAS' URCHIN

Lissodiadema purpureum

GLASS-SPINED URCHIN

Acanthocidaris hastigera

SPEAR URCHIN

Prionocidaris hawaiiensis

HAWAIIAN THORNY URCHIN

Diadema sp. 1

UNIDENTIFIED LONG-SPINED URCHIN

Diadema sp. 2

UNIDENTIFIED THIN-SPINED URCHIN

INDO-PACIFIC / HAWAII

Heterocentrotus mamillatus

SLATE PENCIL URCHIN

Colobocentrotus atratus

SHINGLE or HELMET URCHIN

Echinometra mathaei

PALE ROCK-BORING URCHIN

Echinometra oblonga

BLACK ROCK-BORING URCHIN

Echinostrephus aciculatus

NEEDLE-SPINED URCHIN

Echinothrix diadema

BLUE-BLACK URCHIN

Diadema paucispinum

LONG-SPINED URCHIN

Diadema savignyi

BLUE-LINED LONG-SPINE URCHIN

Echinothrix calamaris

BANDED URCHIN, banded morph

Echinothrix calamaris

BANDED URCHIN, black morph

Tripneustes gratilla

COLLECTOR URCHIN

Astropyga radiata

BLUE-SPOTTED URCHIN

Nudechinus verruculatus

WARTY SAND URCHIN

Pseudoboletia indiana

PEBBLE-COLLECTOR URCHIN

Eucidaris metularia

TEN-LINED URCHIN

Chondrocidaris gigantea

ROUGH-SPINED URCHIN

Rhynobrissus hemiasteroides

HALF-STAR HEART URCHIN

Brissus latecarinatus

HEART URCHIN

Clypeaster reticulatus

RETICULATED SEA BISCUIT

Clypeaster sp.

GIANT SEA BISCUIT

Echinocyamus spp.

MINIATURE HEART URCHIN

INDO-PACIFIC

Toxopneustes pileolus

FLOWER URCHIN

Diadema setosum

ORANGE-RING LONG-SPINE URCHIN

Mespilia globulus

GLOBE URCHIN

NORTHEAST ASIA

Hemicentrotus pulcherrimus

GREEN SEA URCHIN Bafun-uni

Strongylocentrotus intermedius

SEA URCHIN Ezo Bafun-uni

Pseudocentrotus depressus

RED SEA URCHIN Aka-uni

NORTHEAST PACIFIC

Strongylocentrotus droebachiensis

GREEN URCHIN

Strongylocentrotus purpuratus

PURPLE URCHIN

Mesocentrotus franciscanus

RED URCHIN

Centrostephanus coronatus

CROWNED URCHIN

Lytechinus pictus

WHITE URCHIN

TROPICAL WESTERN ATLANTIC

Meoma ventricosa

RED HEART URCHIN

Clypeaster rosaceus

INFLATED SEA BISCUIT

Diadema antillarum

LONG-SPINED URCHIN

Echinometra viridis

REEF URCHIN

Eucidaris tribuloides

SLATE-PENCIL URCHIN