A blue-crab on the sand.
blue crab definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of a genus (Callinectes) of crabs, esp. a blue-legged, edible swimming species (C. sapidus) of the Atlantic coast of North America
blue crab definition by American Heritage Dictionary
An edible, bluish swimming crab (Callinectes sapidus) that has a wide distribution along the Atlantic and Gulf coasts of North America.