Miscellaneous - Sounds Wild
Shrimp Change Sex


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Shrimp change sex

After a day of salmon fishing, a boater in Southeast Alaska heads to a quiet bay for the evening. Before heading out in the morning, he set a string of shrimp pots off the mouth of a silty glacial river, and now he's hauling up those cage-like traps. He's caught a few dozen coonstripe shrimp, delicious five-inch-long crustaceans.

Five species of pandalid shrimp are found in the cool waters off the coast of Alaska. Sidestripe and coonstripe shrimp are renowned for their sweet flavor. Pink shrimp are the foundation of the commercial trawl shrimp fishery in Alaska. Humpy shrimp range from Washington's Puget Sound to the Arctic coast of Alaska. Spot shrimp are the biggest shrimp in the North Pacific and are highly valued by commercial pot fishers and subsistence users alike.

Pandalid shrimp are among the relatively few animals that exhibit protandrous hermaphroditism. Each individual spends the early mature part of its life as a male and later transforms into a female for the balance of its lifetime. For example, a pink shrimp will typically mature sexually as a male, spawn one or more times, pass through a short transitional phase and subsequently mature and spawn as a female.

Shrimp spawn in the fall and the eggs incubate over the winter. In the spring the eggs hatch into planktonic, free-swimming larvae. By mid-summer, the larvae have undergone several molts, rapidly increasing in size after each molt. After the last larval molt the juvenile shrimp settles to the bottom. After a year or so, the juvenile molts and develops into a mature male and may spawn as a male for one or two seasons. Some juveniles, however, never mature into males; instead, they develop directly into females.