Brilliant Coral Gall Crab

Pseudocryptochirus viridis

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Family: Cryptochiridae
Genus: Pseudocryptochirus
Species: Pseudocryptochirus viridis

The brilliant coral gall crab (Pseudocryptochirus viridis) is a tiny, shiny green crab that lives in shallow pits on stony corals. Its glossy, iridescent colour makes it one of the most eye-catching coral gall crabs.

It is only a few millimetres across. Like all coral gall crabs, the female settles on a living coral and the coral grows around her to form a protective pit, from which she feeds on mucus and particles. The species is especially associated with Turbinaria and related corals.

This crab has been recorded in the Philippines, where it lives hidden on coral reefs. Finding one takes a careful search of coral surfaces and a strong macro lens.