The blue crab is the major commercial crab of the Atlantic and Gulf coasts. Like all crustaceans, the blue crab must shed its shell to grow. Unlike on the West Coast, where soft-shelled crabs are protected from harvest, in the South an industry is built on capturing blue crabs shortly before they shed their shell. At this time they are called "busters" for they will soon bust out of the shell. They are held in live tanks until they molt, then are immediately transported to market.
Soft-shell crabs are graded into four sizes, known as whales, hotels, jumbos hotels and mediums. The larger sizes are proportionately more expensive and meatier. But jumbos and mediums are the most commonly available. With these sizes you will need one per person for a first course and two for a main course.
Soft-shell crabs are meant to be sold alive, but many times they are mishandled and die soon afterward. If a soft-shell crab is dead or has been frozen, smell the body. If the crab has been dead too long or frozen when dead, your nose will know. To clean a soft-shell crab, snip off its mouth parts and eyes about 1/4 inch. This immediately kills the crab painlessly. Lift the pliable shell and pull out the finger-like feathery gills. Also remove the bell-shaped flap or apron from the underside of the body.