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Soft-Shell Crabs

They’re delicious, but what’s their story?

Maryland is renowned for its blue crabs. For many in Chesapeake Country, summer means feasting on the crustaceans in as many forms as possible with a favorite being softshell crabs. Our watermen somehow get the soft crabs to us. But how?
    When blue crabs grow, their exoskeleton, the shell, doesn’t grow with them. It stays the same size, so periodically they need to molt their shell to grow a larger one. When a crab is ready to molt, its shell cracks and the growing crab backs out of it. After molting, the crab will be about one-third bigger. Once a crab gets rid of its old shell, it is temporarily a soft crab. The shell will be totally hard again within three days.
    “The time between sheds depends mostly on how large the crab is,” explains Maryland Department of Natural Resources Bay Stock Assessment Committee chair Glenn Davis.
    The smaller the crab, the more frequently it sheds.
    “The smallest crabs, less than one-quarter inch in width, will shed on back-to-back weeks. Crabs about a half-inch will shed twice per month. Crabs two to four inches will shed during successive months, and so on. The larger crabs become less predictable as to when they will shed. We have seen six-inch male crabs keep their shell for over a year,” Davis says.
    Larger forces also affect when crabs shed.
    There is a correlation between shedding and the full moon, Davis says. “While every crab does not wait to shed on a full moon, shedding activity increases around each full moon. Shedding is also spurred on by thunderstorms. Crabs that are already peelers, close to shedding, will shed when a thunderstorm comes through.”
    To get the soft-shell crabs to you, watermen have to be able to identify the subtle signs that a crab is going to shed when it is brought in. Watermen look for a few things when culling crabs, the most obvious being a red ring around the backfin.
    Once they are brought in off the boat, crabs that have been identified as peelers are placed in shedding tanks to be monitored.
    “We have to keep a close eye on the crabs. They mostly shed at night, so someone has to check the shedding tanks every two hours,” says Liza Evans of Bob Evans Seafood in Churchton. “Staying in the warm saltwater causes their shells to harden, but they won’t harden when they’re out of the water in a cooler, so it’s important that we get them out of the water as soon as we can.”
    You’ll appreciate their vigilance when the crab in your sandwich has a paper-soft shell.


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