The soft shelled crab is a regular blue crab caught in an embarrassing state of exoskeletal undress.
Like a school kid in mid-puberty, the crab routinely outgrows its shell and needs to get rid of its confining duds. The biological routine is to binge eat like a monster, absorb as much water as possible, and shred the shell like a gluttonous Homer Simpson doing his impersonation of the Incredible Hulk. A crab in this pre-molting mode is called a “buster crab” (insert old Flash Gordon joke here). As the covering breaks, the crab scampers off with a larger, softer shell, which starts to harden in about twelve hours.
Unfortunately for the crabs, this stage of development makes them vulnerable, tasty, and popular with diners. With no hard shell to crack, soft-shelled crabs require very little cleaning and can be eaten — claws, legs and all — without a nutcracker in sight. The most common preparations are sautéed in butter, lightly panneed or deep fried and crammed legs-up in a Jazzfest poboy.
These days very little is left to nature and even less to chance. Though the seasons for live soft-shells are still spring (March-June) and early fall (September-October), crab processors have elaborate “cage and tank” setups to monitor and manage the crab’s change of clothing. During the peak seasons, you can find soft shells live and kicking; other times you’re most likely getting a frozen busters.