Rainbow Land Crab

Cardisoma armatum

The rainbow land crab (Cardisoma armatum), also sold as the African rainbow crab or Nigerian moon crab, is a large semi-terrestrial crab from West African coastal wetlands, mangrove edges, and nearby burrow systems. Adults are valued in the pet trade for a blue to purple carapace, orange-red legs, and pale claws, although colors vary with age and molt condition. Despite the common name, it is not a fully terrestrial animal; the gills must stay moist, and individuals spend much of their time digging, hiding, and emerging at night to feed.

Successful keeping is closer to a humid paludarium than a simple aquarium. A single adult often does best because these crabs are territorial and can injure tankmates, especially around molts. Deep damp substrate for burrowing, a secure lid, mineral sources, and both land and water access are central to welfare; many keepers provide freshwater and a marine or brackish pool. The diet is omnivorous, including plant matter, protein foods, and calcium-rich items. Captive breeding is uncommon because the larvae require planktonic development in saline water, so most animals offered for sale are wild collected.