Tan Sea Urchin

A tan sea urchin from the deep seas of Curacao.
Trish Mace, Smithsonian Institution

This tan urchin, Conolampas sigsbei, is one of only two known deep-sea urchins that cover their tops with small rocks and shells. Many shallow species cover themselves for reasons that have been determined experimentally. However, none of these explanations make sense for urchins living in the deep sea. Deep-sea urchins are not dealing with UV light, they don't need camouflage in the dark, and as mud eaters they are not collecting algae to feed on. Dr. Pawson, from the National Museum of Natural History, is experimenting with Conolampas to figure out why these urchins cover themselves. One possibility is, rather than using top spines, these urchins use a debris covering to protect their genital pores. You can see a second deep-sea urchin here

The urchin was found off the coast of Curaçao by the Deep Reef Observation Project (DROP).