"Sea Potato" (Echinocardium cordatum)
…a species of Loveniid sea urchin which boasts a mostly cosmopolitan distribution. Where it occurs in temperate seas in the north Atlantic, west Pacific, around Australia and New Zealand, as well as South Africa. Sea potatoes are often seen on sandy sea beds, where they will bury themselves constructing small burrows which are lined by mucus secretions. Detritus and other nutrients will collect on these secretions, and made their way to the central area of the burrow, where the sea potato will feed on them. Sea potato burrows are known to house a wide range of commensals, especially the bivalve Tellimya ferruginosa.
Image: Hans Hillewaert