Attaches sponge, hydroid and rubbish to its own shell until nothing of the crab shows.
A long-legged spider crab with a carapace to about 5 cm, entirely covered in hooked setae to which it attaches pieces of the surrounding bottom — sponge, hydroid, algae, ascidian, shell fragments and, on a muck site, plastic and fibre as readily as anything living. The covering is applied deliberately, piece by piece, and a crab moved to new ground will re-dress itself to match within a day or two. What a diver sees is a moving clump of debris with legs.
Decoration is maintained rather than grown, so it survives a moult: the crab strips its old covering and transfers it. Nocturnal, and out in the open on rubble and sand after dark; through the day it is wedged into cover and effectively unfindable. Recorded from the shallows to about 30 m. The photograph most worth taking is the face — the eyes and the front of the carapace are usually the only part left undecorated — and finding it in the clump is most of the work.
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.
