Genus Cancer, family Cancridae
There are numerous crab species living in our waters and along our beaches. As these animals are preyed upon and or die, some of their body parts are washed up onto the shore.
The arm on the left side of the photo is from a Spider Crab, with barnacles growing on its surface. There are two species of Spider Crabs in Florida, the Longnose, Libinia dubia, and the Portly, Libinia emarginata. They co-exist in the same habit and are very similar. These crabs are unusual in that they are slow and move in a forward direction. They are predatory and feed on Sea Stars.
The Claw on the right is from a Florida Stone Crab, Menippe mercenaria. These crabs are well known for their claw meat. When harvesting from maintained crab traps, one claw is removed and the crab is then released to regenerate another. Crabs used their claws for defense and to hunt prey. Adult Stone Crabs live in slanted 12- to 20-inch underwater burrows.
Live shells should never be taken from any Florida State Park.