Banded Clinging Crab

Mithraculus cinctimanus is a small crab with an oval carapace slightly longer than it is wide. The front third is slightly hairy and the surface of the hind two thirds is roughened by small tubercles. The front edge has several blunt spines. The colour of the carapace is variable often being olive brown with several large creamy patches. The legs have bands of the same colours and their outer segments are hairy. The fingers of the chelae do not completely close and have rounded tips. An adult Mithraculus cinctimanus is about 22 millimetres (0.87 in) long.

Mithraculus cinctimanus is found in the Caribbean region its range including Florida, the West Indies, Curaçao, Colombia and Venezuela.

Mithraculus cinctimanus is usually found living commensally with a sponge, coral or a sea anemone. The host is often the sun sea anemone Stichodactyla helianthus or in deeper water, the anemone Lebrunia danae. On this latter anemone, Mithraculus cinctimanus is part of an assemblage of commensal invertebrates each occupying its own characteristic position. It is found hiding under the rim of extended pseudotentacles and when these are retracted, it also retreats leaving only its chelae, eyes and the front part of its head exposed. It seldom moves away from the anemone and seems to be immune to the stings produced by its host's nematocysts.