Hermit Crabs: There are at least 9 species of “hermit crabs” in the Florida Keys. As with many species in Florida, the hermit crab grows quite large due to the warm waters and mild winters. Hermit crabs are “mobile home” dwellers using abandoned sea shells as their home. As they grow, a new larger home must be found to accommodate its larger body size. Hermit crabs can be very competitive when it comes to finding a new, empty shell. Usually the largest will win the new home, abandon his shell for the larger, then the next biggest will occupy his former home, and down the line a swapping of homes occurs.
Horseshoe Crab: This fascinating, prehistoric looking creature has been around for over 400 million years. They are usually shunned by most who think they are dangerous, but they do not sting or bite! Horseshoe crabs are found all over Florida and are not seen often because they are nocturnal feeders. You can find their molted carcasses scattered on the beaches year round.
True Crabs: There are at least 17 species of “true crabs” in the Florida Keys. True crabs are decapod crustaceans and belong to a group called the “Brachyura”. They have a very short projecting “tail” and their small abdomens are completely hidden under the thorax. All crabs have one pair of pincers and four pairs of walking legs. They are the first pair of legs on a crab and are used for holding and carrying food, digging, cracking open shells and warning off would be attackers. The carapace protects the internal organs of the head, thorax and gills. The eyes are on the ends of short stalks and the mouth parts are a series of pairs of short legs, specialized to manipulate and chew food. The abdomen is small and tightly held under the body. The size of the abdomen distinguishes whether the crab is male or female.