One of the largest reef crabs here, up to about 15 cm (6 in) across, with a smooth deep red to orange-brown shell and heavy black-tipped claws of unequal size. It spends daylight wedged under coral heads and in crevices, and comes out at night to break open snails, hermit crabs and urchins.
The claws are strong enough to take a finger seriously, but the more important warning is chemical: several large xanthid crabs carry paralytic toxins in their flesh, unaffected by cooking, and deaths from eating them are on record across the Indo-Pacific. Nothing about that matters underwater - the crab is not aggressive and has no interest in a diver - but it is a reason this animal never belongs on a plate. Rich colour and size make it one of the more satisfying finds on a night dive, usually as a pair of claws filling a hole.
- large smooth shell, deep red to orange-brown
- heavy black-tipped claws, unequal in size
- wedged deep under coral by day
- width up to 15 cm
