This Week’s Creature Feature … The Bay’s Winter ­Jellyfish, the Lion’s Mane

Few things look scarier than a gelatinous mass with tentacles twisting in the Bay.
    Chesapeake swimmers endure sea nettle stings in summer. But few have been stung by a lion’s mane jelly, the world’s largest known jellyfish species. Lucky for us, these jellyfish are seasonal inhabitants of the Bay from November to March.
    “They are very temperature-dependent, as they thrive in cooler waters,” says David Moyer, Calvert Marine Museum curator of Estuarine Biology.
    Lion’s mane jellyfish prefer northern latitudes — the Arctic Ocean and northern Pacific.
    But they tend to travel. The species in our waters is planktonic, meaning it goes where the currents take it.
    “Its presence in our water is entirely the result of prevailing water currents bringing them into the Bay,” Moyer says.
    They come when oceanic conditions are optimal for dispersing them here and it is cool enough for them to survive.
    Thus, says Moyer, “the chances of spotting a Lion’s Mane Jellyfish in the Chesapeake Bay are rather good but unpredictable.”
    You’ll know one if you see one.
    “They’re unlike the other species of jellies that we get in that they are more easily seen with their characteristic lion’s mane-like appearance of the tentacles and feeding arms dangling beneath their orangey bell,” Moyer says.
    The largest one recorded had a bell diameter of seven and a half feet and tentacles 120 feet long. Fortunately, the Lion’s Mane roar is bigger than its bite. A sting causes only an itchy rash and mild burning sensation.
    Walk a Bay beach in cold weather, and you’re apt to see Lion’s Manes floating in the shallows or washed up on the strand.