Description:
The blue land crab, also called the great land crab, is a large burrowing crab whose distribution on land is generally limited to within 3 - 5 miles of the ocean. Carapaces of large individuals may grow to over 4 inches in length,  with large crabs weighing over 1.3 pounds.  Juveniles generally have brown carapaces and orange colored legs.  Adults of both sexes have carapaces that range in color from dark blue to various shades of brown to gray/white.  Ovigerous females frequently appear light gray or white. The eyes are stalked and fairly widespread.  Males are identified by having unequal claws as shown in the top photo at right.  

Habitats: 
Adults utilize a range of habitats and tolerate a wide range of salinities.  Blue land crabs are limited to areas where they can burrow to intersect the water table and maintain a 1-2 liter pool in the bottom of the burrow. Thus they are functionally limited to areas where the water table is within approximately 7 feet of the surface.  Competition for optimum shoreline burrows may be the force that drives terrestrial crabs to migrate to inland areas.

Range:
Cardisoma guanhumi is a circumequatorial species found throughout estuaries in 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.  Within Florida, it has been observed in large numbers as far north as Vero Beach, with water temperatures limiting population growth beyond this location.  C. guanhumi is found throughout the Indian River Lagoon, but is much more common in the central and southern portions of the lagoon.