Coral Commensal Crab

Trapezia sp.

Identification	A small, flattened, brightly colored crab (cream, pink, red or spotted, depending on species) that lives among the branches of Acropora and Pocillopora corals. Also called a Guard Crab.
Maximum Length	1″
Origin	Indo-Pacific
Minimum Tank Size	20 Gallon
Reef Compatibility	Reef safe. A beneficial symbiont that actively protects its host coral.

Behavior

A fascinating obligate coral symbiont that shelters within branching SPS corals and defends them, driving off coral predators such as Acropora-eating flatworms and even nipping at crown-of-thorns starfish. In return it feeds on coral mucus. Harmless to the coral itself.

Diet & Feeding

Coral mucus and fats from its host, plus captured detritus and meaty scraps; largely self-sustaining in a reef with SPS.

Cautions

Needs a host branching coral (Acropora, Pocillopora or Stylophora) to thrive. Harmless to corals and fish.