Gecarcinidae Cardisoma Cardisoma guanhumi male. Cardisoma guanhumi , the blue land crab, is a large burrowing crab whose distribution on land is generally limited to within 5 km of the ocean. Large individuals may grow to over 11 cm and weigh over 500 grams.
Juveniles generally have brown carapaces and orange colored legs.
Ovigerous females frequently appear light gray or white. Cardisoma guanhumi is a circumequatorial species found throughout estuarine regions of the Caribbean, Central and South America including Columbia, Venezuela, the Bahamas, and Puerto Rico. Within the U.S. it is limited to the Gulf of Mexico and coastal Florida and is rarely found more than 8 km from the ocean. It is found in greatest concentration on low lying ground, and burrow concentrations in these optimum habitat areas may exceed 7500 per acre. The population distribution of this species is heavily influenced by water temperature.