A small sand crab that holds an urchin, a shell or a piece of debris clamped over its back.
A dorippid crab with a squarish, roughened carapace to about 4 cm, sand-brown and usually carrying a film of sediment. The first three pairs of legs walk. The last two pairs are short, turned upward over the back and tipped with small hooks, and they are held permanently raised, gripping whatever the animal has picked up and clamping it down onto the carapace. That posture is fixed in the group and a crab without a load still holds the legs as though it had one.
What is carried varies. A sea urchin is the usual find on these coasts, but bivalve shells, sponge, a leaf, a scrap of plastic and a jellyfish have all been recorded, and the object is generally wider than the crab. The purpose is cover, and it works: what is seen on the sand is the object, not the animal, and the giveaway is that it moves in a way it could not move on its own.
The crabs are on open sand and silt, often part-buried during the day with the load resting flush on the surface. A load that has been lost is replaced quickly, and animals turn up carrying objects that were plainly picked up rather than grown. Recorded from about 5 to 30 m.
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.
