Frightful yet delightful; ghostly nettles haunt Chesapeake waters

Chesapeake summers. They’re hot and humid. We are drawn to the Chesapeake Bay and its many rivers for a cooling dip.

Whether you are along a beach, dock or on a boat, there is that one animal that makes you leery of entering the water. But this intimidating creature is not a shark. The animal that rules Chesapeake Bay summer waters is the simple sea nettle (Chrysaora quinquecirrha) whose graceful, gelatinous body keeps us onshore not wanting to risk its inevitable sting.

A member of the jellyfish family, sea nettles inhabit the Bay year-round. Before taking on the distinctive umbrella shape, sea nettles go through a variety of growth stages, neither recognizable nor seen with the naked eye. It is only the fearsome adult “medusa” form we are all too familiar with.

Adult sea nettles spawn from late summer to early fall, after which they die. Males release sperm into the water and females pump the sperm-laden water through their bodies to fertilize their eggs. Females then release minute larvae known as planulae. The planulae float at the mercy of the currents and many predators, including other sea nettles. After a few days, the surviving larvae settle to the bottom.

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