This sea-dwelling sea cucumber, Enypniastes eximia, feeds on sand and mud, then swims gracefully off the bottom. Enypniastes eximia can be up to a foot in length.
Almost all sea cucumbers (which are in Echinodermata, the same phylum as starfish and sea urchins) are bottom dwellers, which lie on or burrow into the sediments and eat mud or sand to get the attached organic material. E. eximia is one of a small group of swimming sea cucumbers. It also feeds on bottom sediment, which it stuffs into its mouth with the group of tube feet surrounding the mouth. However it is also capable of swimming up above the bottom, by undulation of the cape-like structure around the top of the animal. It is a graceful, if slow, swimmer, but can be found several hundred feet above the bottom. Through the transparent body wall, one can see the intestine and other internal organs. E. eximia has luminous organs on its skin, which may deter predators.