Little jellyfish packs a big wallop

No bigger than a bottle cap, “the clinger” inflicts a knee-buckling sting that can require emergency treatment.

"The clinger" is about the size of a quarter and lives in eel grass in quiet, protected areas of saltwater ponds. — Photo by Dan Blackwood/WHOI

On June 25, 17-year-old Florida resident Michelle Langone was rushed to Falmouth Hospital with respiratory failure and partial paralysis after being stung by a jellyfish known as “the clinger” while swimming off a dock in Waquoit Bay in Falmouth. “All of a sudden I felt my lower back tense up, and I couldn’t stand up straight, and like as if all my muscles were paralyzed,” she said in a June 26 interview with Boston television station WCVB. “I was cramping. It spread to my chest, and I couldn’t breathe.” Twenty-four hours after the sting, Ms. Langone said, she was still in pain, and had “tingling sensations” in her body. Ms. Langone’s mother described a scene out of a Stephen King novel, where her family was surrounded by a swarm of thousands of the stinging creatures.

According to Mary Carman, research specialist at the Woods Hole Oceanographic Institute (WHOI), the clinger, Gonionemus vertens, is also alive and well on Martha’s Vineyard. “We’ve had sting reports from Farm Pond and in Stonewall Pond,” she told The Times. Ms. Carman knows firsthand about the pain of a clinger sting — she was stung on the lip while doing research at Farm Pond. “It felt like five hypodermic needles going into my lip at the same time,” she said. “It’s not fun.”
Oak Bluffs Shellfish Constable David Grunden has also been stung several times at Farm Pond. “It’s a very intense burning sensation,” he told The Times. “It went away in several minutes. But it has caused some people to go into anaphylactic shock. Clingers can stick to your skin, so chances are one sting will actually be multiple stings.” Mr. Grunden said he found the first clinger in Farm Pond in 2006. He said the treatment for a clinger sting is the same as for a garden-variety jellyfish sting — douse the wound with white vinegar. Both Mr. Grunden and Ms. Carman were stung in previous years, and so far this summer, no clingers have been sighted in Stonewall or Farm Pond. “We’re not sure why that is, but mostly likely it’s a little early in the summer for them on the Vineyard,” Mr. Grunden said.

Invasive invertebrate
The clinger is an invasive species from the northern Pacific that was first documented in Woods Hole in 1894 by biologists. “They went away in the 1930s when there was an eelgrass blight, but in the past 15 to 20 years, we’ve been seeing them come back, and we’ve been getting reports of some pretty nasty stings,” Annette Frese Govindarajan, research specialist at WHOI, told The Times.

There is conjecture in the scientific community that its firebrand sting has actually evolved since its East Coast arrival. There is certainty, however, that more people are being stung.

“It’s alarming that there are an increasing number of reports,” Ms. Govindarajan said. “The population is spreading. We’re finding them where we haven’t seen them in the past. The symptoms reported by the girl who was stung in Waquoit Bay are similar to other reports we’re getting, with the breathing difficulty and temporary paralysis.”

Part of what makes the presence of clingers so vexing is that they are so small, between the size of a dime and a quarter, and they’re extremely well camouflaged, almost completely translucent except for a thin brown, orange, or purple border and and two thin lines that cross in the center.

Clingers get their sobriquet because they spend most of their life clinging to eelgrass. “The stings occur when people disturb eel grass,” Ms. Govindarajan said. “They don’t swarm. They live in more quiet, protected areas in saltwater ponds where there’s a lot of eelgrass.”

Ms. Govindarajan said clingers pose no threat to beachgoers. “They don’t live in the open ocean,” she said. “They can’t handle water where people want to swim.”

Mysterious creature

Scientists know that the clingers live one summer as an adult before they die off in early autumn. Before they reach adulthood, they go through the microscopic larvae and polyp stages. It’s not known how long the polyp stage can last, but it is known that the polyp can form an outer shell so it can survive the New England winter. It’s likely that the clinger survived the eelgrass blight in the 1930s by hunkering down in the polyp stage. “The polyp stage is interesting, because one polyp can make several jellyfish; it’s an asexual stage in their life cycle,” Ms. Govindarajan said. “The adults reproduce sexually, and they produce larvae, which form polyps, and the polyps in the asexual stage make the jellies,” she said. “When jellyfish occur in blooms, it’s because a polyp can make a lot of jellies, and a lot of polyps can make an awful lot of jellies.” Although the jellyfish was first discovered in Woods Hole over a century ago, scientists have yet to determine what preys on clingers, and why an animal that feeds on small zooplankton has a sting so toxic it can temporarily paralyze humans.

“There’s a lot we don’t know,” Ms. Govindarajan said. “Right now we’re trying to understand why they’re coming back every year.”