The Echinometridae Family includes 28 species comprising 9 genus (Echinometra (10 species), Heliocidaris (6), Zenocentrotus (2), Heterocentrotus (2), Echinostrephus (2), Colobocentrotus (2), ...)

Phylum      : Echinodermata
 Subphylum   : ⤷Echinozoa 
  Class       : ⤷Echinoidea 
   Subclass    : ⤷Euechinoidea 
    Infraclass  : ⤷Carinacea 
     Subterclass : ⤷Echinacea 
      Order       : ⤷Camarodonta 
       Infraorder  : ⤷Echinidea 
        Superfamily : ⤷Odontophora 
         Family      : ⤷Echinometridae

Common name : shingle urchin, cliff-clinging urchin, helmet urchin or rock urchin

Aspect : this particular species has a shell in the shape of a flattened dome covered with purple "radioles" which form a sort of nested scales; this particular shape allows it to offer no grip on extreme wave-swept shores; upper spines form smooth “armor” while lateral spines form a skirt that improves grip and reduces lift. the lower surface equipped with powerful suckers which can retract or lengthen, in order to allow it to move or else to cling to rocks; usually black, dark brown, or dark purple; size range 4 to 10 cm

Feeding : algal grazer using "Aristotle's lantern" (five-toothed jaw) to scrape encrusting red coralline algae

Environment : endemic to Indo-West Pacific (primarily Hawaii, Maui, Oʻahu), with sporadic records in East Indies, Bay of Bengal, Andaman Islands, south Java (rediscovered 2025) but endangered in Japan/Cook Islands; on hard rocky shorelines in wave-swept intertidal zones at maximum depth of 4 m

Colobocentrotus (Podophora) atratus (Linnaeus, 1758)

Total collection for Echinometridae : 1 species (7 shells in total)