Living specimens of the speckled crab are usually found almost totally buried in the sand or in shallow water. The black/grey and white pattern serves as excellent camouflage. They are swimming crabs w/ flattened bodies and the 5th and last pair of legs flattened and oar-like. The eggs of females look like attached sponges.A very good crab article, "The Blue Crab in Florida" is here:
http://research.myfwc.com/engine/download_redirection_process.asp?file=ls1_3245.pdf&objid=37176&dltype=publication