Calappa calappa, also known as the smooth or red-spotted box crab, is a tropical marine species of crab with an Indo-Pacific distribution, and showing great variability in its patterning and colouration. First described as Cancer calappa by Linnaeus in 1758 from a specimen originating from Ambon Island, and later in 1781 as Cancer fornicatus by Fabricius, it was finally placed in the genus Calappa by Borradaile in 1903. It has been called the Darth Vader crab because of its appearance from the front. The name calappa is associated with kelapa, the Malay word for 'coconut', and is probably an allusion to the coconut-shell shape of the carapace.
Occurring in the intertidal zone to a depth of 50 m, this species has a carapace of about 15 cm, indistinctly rugose on the anterior half, with wavy lines edging the posterior. Except for the front, the carapace curves down on all sides, covering the eight ambulatory legs in a design similar to that of horseshoe crabs. The claws are large and flattened, also with a wavy line pattern, fitting snugly under the carapace and providing armoured protection for the crab's front. It is active during the night hours, and is able, when threatened, to swiftly burrow beneath the sand. It feeds mainly on mollusks such as clams, steadying them with its legs and then, using its pincers, either prising the valves apart or breaking them.
Distribution - Mombasa, Seychelles, Aldabra Island, Madagascar, Mauritius, Andamans, Japan, Taiwan, Borocay, Palau, Indonesia, Papua New Guinea, Shark Bay, Abrolhos Islands, New Caledonia, Hawaiian Islands, Marquesas, Society Islands.
- World Register of Marine Species
- National Institute of Oceanography
- Calappa calappa gallery
- Calappa philargius eating clam
- Calappa calappa eating Terebra maculata