These tiny, spider-like jellyfish are only about the size of a dime.
But don’t let their size fool you: Clinging jellyfish stings pack an outsize punch — and experts say they’re appearing in record numbers in a New Jersey bay this year, the Asbury Park Press reports.
Montclair State University jellyfish expert Paul Bologna said he and a team of researchers have discovered almost 300 of the animals in Barnegat Bay and the Metedeconk River, which is more than have turned up in past years, according to the newspaper.
“When we’re finding hundreds, or 500 of these, it really means that there are thousands and tens of thousands of polyps (or baby jellyfish) ... out in the local waterways,” Bologna said of the clinging jellyfish, whose sting he described as causing “a whole body charley horse” that gets worse and worse with time, the Asbury Park Press reports.
New Jersey isn’t the only state where people dipping into bay waters should be wary of the jellyfish: In the 1990s stings were first reported in Massachusetts’ Cape Cod, and since then the jellyfish have been documented in New Hampshire, Rhode Island, Connecticut and New York, the Providence Journal reported last year.
But the animal’s range extends even further than that. The clinging jellyfish can be found all the way from Maine to North Carolina, according to the New Jersey Department of Environmental Protection.
“It’s a public health issue,” Bologna said last year after stings were reported in Rhode Island, according to the Providence Journal. “Are you going to let your kids go in the water if they end up in the hospital?”
Clinging jellyfish aren’t supposed to be in the Atlantic Ocean at all. They’re native to the Pacific, and were introduced to the United States’ Eastern seaboard as early as the 1890s in Woods Hole, Massachusetts, the New Jersey Department of Environmental Protection says. But the animals all but vanished in the 1930s when eelgrass beds along the Atlantic were killed off, according to the Providence Journal.
New Jersey’s fact sheet on the invasive jellyfish says they “thrive in temperate regions, and can be found in sheltered shallow bay and estuarine waters where tides are not strong enough to dislodge them” and “are not typically found in coastal ocean waters.” They can grow up to an inch across, but can expand to three inches — and have up to 90 little tentacles that pack stinging cells.
“They carry these paralysis toxins that cause your muscles to tense up,” Bologna said, according to CBS New York. “They use those to catch fish so the fish don’t run away, but it also causes intense pain.”
A man likely stung by a clinging jellyfish in 2016 in New Jersey described the pain as excruciating, the Asbury Park Press reported.
“I thought I was going to die,” said Matt Carlo, then 20, according to the newspaper. “That’s how much pain I was in.”
Carlo said the pain didn’t subside until he was hospitalized and given a morphine injection, the newspaper reported.
“The pain wasn’t on my skin, the pain was inside,” Carlo said, according to the Press. “My mom was crying I was in so much pain. They didn’t know what to do.”
During the day, the creatures cling to shells or vegetation, but at night they feed on zooplankton and other small animals, the state fact sheet said.
New Jersey environmental officials said the jellyfish were either recently introduced to the state or had gone unnoticed before stings in the last few years. The state said “clinging jellyfish are not likely to be abundant in areas heavily used by swimmers, but could affect casual waders and people gathering shellfish near eelgrass beds.”
If someone is stung, New Jersey officials advise the victim to first apply white vinegar to the sting site “to immobilize any remaining stinging cells” and then to rinse the skin off with saltwater and use gloves to get rid of any tentacles that might be left behind.
Ice packs or a hot compress might relieve pain, the state’s fact sheet said, but if the pain continues or gets worse the victim should get medical care.