Most of our crustacean friends– crabs, lobsters, and their kin– call the sea their home. But a few adventurous groups of these hard-shelled, many-legged invertebrates left the sea long ago to take up residence in freshwaters. The most familiar of the freshwater crustaceans are the crayfish (also called crawdads or crawfish). Of course, crayfish are not ‘fish,’ but are close relatives of the ocean-dwelling lobsters.
