Sea urchins, like starfish, belong to the echinoderm family. They feed mostly on algae, but are sometimes necrophagous. For this purpose they have five very strong teeth called ‘Aristotle’s Lantern’. Between their spines they have tube feet that enable them to move.
Echinidae family, Echinoderms
From 10 to 17 cm in diameter
North Sea, North East Atlantic, English Channel