This is a sumo crab, family Dorippidae, perhaps the genus Ethusa. One must look at the carapace in greater detail to be certain of the genus and species. Like sponge crabs (family Dromiidae), they use specialized hind legs to hold on to camouflaging material such as sponges. It can be tough to tell the two families apart, but sumo crabs tend to have longer legs and longer eyestalks than dromiids and can live in deeper water. They get their common name of "sumo crab" because some of them have grooves on the carapace that look like the scowling face of a sumo wrestler.

Text contributed by Mary Wicksten, Texas A&M University.