Spotted moon crab

Description:

Moon crabs usually have a long spine on each side of the carapace, and all their legs are distinctly flattened laterally into paddle-like structures. Moon crabs are sometimes confused with swimming crabs (family Portunidae), but the latter only have a pair of back legs that are paddle-like. The paddle-like legs not only allow them to be good swimmers, but excellent burrowers as well. They work like spades and allow the crab to vanish very quickly into the sand. Most moon crabs feed on small invertebrates or scavenges.

Notes:

The Common Moon Crab can be distinguished from other similar-looking local species by the differences in the chelipeds - the ridge on the upper finger of the pincer is made up of a series of small bumps, and there is an obvious oblique ridge on the outer surface which starts near the base of the lower finger and ends with a sharp spine towards the base of the pincer. The maximum carapace width of this species is about 5cm (excluding the spines).