Ghost Crabs

This is the pink ghost crab, Ocypode ryderi, which inhabits the sandy beaches of East Africa from Somalia to Durban in South Africa; this picture was taken in Tanzania. Ocypode has a wide distribution in the tropical and subtropical zones. They are nimble beasts, running on the tips of their legs, and live between the high- and low-water marks, mostly feeding off carrion and small living things brought in by the waves.

They dig a short burrow in the sand from which they venture out to dispute territory with their numerous neighbours. Our dog in Mombasa, Susie, a dachshund, used to chase them madly around the beaches but rarely caught one. She had more luck, however, when she dug them out of their burrows.

As the tide comes in the burrows fill with water and the crabs which, when running around the sands, can breath air, return to the water, where they are frequently tumbled around by the waves.

This is the Atlantic species Ocypode quadrata, at home on a beach in Jamaica. It's one of twenty-two species of Ocypode, this species extending down the western Atlantic seaboard from Massachusetts to Brazil.

They're called ghost crabs because they are most active at night. Walking along a moonlit beach one can see but not hear them, often when they're silhouetted against sand wetted by the swash of an incoming wave.