Description

Cardisoma carnifex, commonly known as the brown land crab, is a large, semi-terrestrial crab species belonging to the family Gecarcinidae. It is widely distributed in tropical coastal regions across the Indo-West Pacific, ranging from the eastern coast of Africa and the Red Sea to islands in the central Pacific, such as the Tuamotu Archipelago.

Physical Characteristics:

• Carapace Width: Up to 12 cm in males.

• Coloration: Brown to reddish-brown body with yellowish claws; claws are asymmetrical.

• Carapace Shape: Heart-shaped, a characteristic feature of the genus Cardisoma .

Habitat and Ecology:

Cardisoma carnifex inhabits various coastal environments, including mangrove swamps, coastal shrubs, and windbreak forests. It prefers areas where the water table is close to the surface, allowing it to access water without being submerged. These crabs are primarily nocturnal and terrestrial, emerging at night to forage and returning to their burrows during the day.

Reproduction and Behavior:

Reproduction in Cardisoma carnifex is closely tied to lunar phases and tidal cycles. Mating typically occurs during spring high tides, and after mating, males often guard their mates’ burrows by plugging the entrances, a behavior observed in other land crab species as well . The larvae are released into the sea, where they develop before returning to land as juveniles.

Distribution:

This species is found along the coasts of East Africa, the Red Sea, the Indian Ocean, and the Pacific Ocean, including regions such as the Seychelles, Madagascar, and various Pacific islands.