Ridged Swimming Crab

Charybdis natator has a fan shaped carapace which is brown to orange in colour on the dorsal surface the ventral surface is bluish mottled with white and pale red spots and the legs are dark, reddish brown in colour. The carapace is densely covered with short pubescence which is absent on the distinct transverse granulated ridges in the anterior surface. There are six spines on each side of the carapace. There are eight small rounded lobes between the orbits which are set close together. The antennae are outside the orbits but are in contact with the supraorbital lobe at their base. The chelipeds are covered with large granules and/or squamiform markings and have distinct black tips with blue spots, this bright blue colour is also visible at the base of the cheliped.

Charybdis natator is found throughout the Indian and Pacific Oceans from eastern South Africa and Madagascar north to the Red Sea and across the Indian Ocean, including the Mascarene Islands and the Seychelles, to the western pacific where it extends north to Japan and south to northern Australia including Lord Howe Island.

Charybdis natator is an unimportant species for fisheries in eastern Africa and in India it is the fourth most important swimming crab caught in the crab fishery whereas in Taiwan and Australia it is much more important. Because of the high rate of meat recovery C. natator may be suitable for aquaculture.