Also called shingle urchin, the helmet urchin is a species of sea urchin in the family Echinometridae. They can be found on rocks nears shores of the Indo-West Pacific particularly in Hawaii. They look very different from other sea urchins as their spines have been modified to be flattened and smooth in order to better withstand the waves that crash against the rocks they live on in order to feed on periwinkles and algae. They are usually a maroon color and grow as big as a softball.
…a species of Echinometrid sea urchin, which occurs in shallow areas in the western Atlantic Ocean and Caribbean Sea. Like other sea urchin species E. lucunter will feed on a range of marine plants and algae. True to its common name E. lucunter uses the teeth on its Aristotle’s lantern to grind away at rock allowing it to conceal itself.
…a species of Echinometrid sea urchin which occurs on reefs in the Caribbean Sea from Florida to Venezuela. Reef urchins will conceal themselves in rock crevices during the day and will emerge at night to feed. Reef urchins are grazers and will feed on a variety of fleshy algae.