Cuts a piece of living sponge to fit and holds it over its back with two modified legs.
A heavy, rounded crab with a carapace to about 20 cm across, covered in short dense setae that give it a felted look, with pink-tipped claws and small red eyes. The last two pairs of legs are reduced, turned upward over the back and ended in small pincers, and their only job is to grip.
What they grip is a sponge. The crab cuts a piece of living sponge, trims it with its claws to the shape of its own carapace, and carries it clamped down over its back for life, replacing it as it grows. The sponge continues to grow and moulds itself to the crab. Sponges are unpalatable to most predators, and a walking sponge attracts no attention. Some individuals use a colonial ascidian or a piece of soft coral instead. Nocturnal, moving slowly over rubble; by day it is wedged under a ledge and looks exactly like the sponge it is wearing. Recorded from about 3 to 30 m.
Older references list it as Dromia dormia.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
