Hāʻukeʻuke kaupali (Helmet Urchin), Colobocentrotus atratus

Adaptations of the amazing Shingle Urchin

The Shingle urchin, Colobocentrotus atrata (Echinometridae), has a peculiar limpet-life morphology, unique among the regular echinoids. 

The aboral spines of Colobocentrotus atrata (on the opposite side to the mouth) are extremely reduced, forming a smooth pavement or plates, and the adoral part (situated near the mouth) is surrounded by a basal skirt of flattened spines. These two features improve the adhesive capacities of the animal and are adaptations to life in areas of extreme wave exposure throughout the Indo West Pacific where this sea urchin lives.

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