The Florida stone crab and the gulf stone crab were once one species. Changes in climate and sea level probably kept two populations separate over time until they became genetically distinct.
Two species of stone crabs exist in the Southeastern United States: Menippe mercenaria in the peninsula of Florida, and Menippe adina in the northern and western Gulf of Mexico. The two species differ in coloration and genetic makeup; they also differ somewhat in reproduction, salinity and temperature tolerance, and ecology. The table and pictures below show the differences in color pattern and habitat.
|Body and Claw Color
||Tan to light or medium gray
||Deep chocolate to maroon
|Body and Claw Markings
||Black spotted, spots usually small but uniform
||Usually solid, occasional mottling of light brown
|Leg Color and Markings
||Dark brown, distinct white bands
||Solid deep chocolate to maroon
||Limestone sand, rocky outcrops, seagrass beds
||Muddy bottoms, rocky outcrops, seagrass beds