Plants live anemones on its shell and moves them across when it changes house.
A large hermit crab reaching about 10 cm, with red-banded legs, stalked eyes on long red-and-white peduncles and a left claw larger than the right. It is recognised less by the crab than by the shell, which normally carries several living anemones of the genus Calliactis fixed to its surface.
The association is actively maintained. The crab detaches an anemone from a shell or from the substrate by stroking it until the pedal disc releases, then places it on its own shell; when it outgrows the shell and moves, it transfers the anemones to the new one. The anemones gain transport and scraps; the crab gains a stinging cover that deters octopus, which are the main predator of hermit crabs here. Most active at night, walking openly across sand. Recorded from the shallows to about 30 m. A crab that pulls into its shell will come out again within a minute if the light is taken off it.
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.