Coral Guard Crab

Care at a glance

Overview

It needs a branching Pocillopora or Acropora colony to live in, in a tank of 40 litres or more at 24 to 27 C and pH 8.1 to 8.4. It gets most of its food from the coral but will take small meaty scraps. Usually only one crab or a mated pair holds a single coral head, since they are territorial toward other guard crabs, and they are safe with corals and other tankmates.

In the wild

The coral guard crab is a tiny flat crab, usually under 2 cm, that lives its whole life tucked among the branches of a single Pocillopora or Acropora colony. It is often colored in lilac, red, or orange with fine spotting. It rarely leaves its home coral.

Good to know

Trapezia cymodoce is an obligate coral symbiont, meaning it cannot live long without a host coral. It feeds on the coral's mucus and fat rich tips, and in return it drives off coral predators, including the crown of thorns starfish.

Did you know

These little crabs defend their coral so fiercely that they will grab and fend off crown of thorns starfish many times their size.

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