Mithraculus cinctimanus is a small crab with an oval carapace slightly longer than it is wide.

[2][3] Mithraculus cinctimanus is found in the Caribbean region its range including Florida, the West Indies, Curaçao, Colombia and Venezuela.

At this stage of their lives, the carapace is often covered with felt-like red algae which provides the crab with camouflage.

[2] 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.