Maritime Aquarium adds tiny toxic invasive jellyfish to “Living Lights” exhibit

Maritime Aquarium/contributed photo

NORWALK, CT – An invasive jellyfish no bigger than a nickel – but one that has sent people to the hospital in agony – now can be seen in a rare public display in The Maritime Aquarium at Norwalk.

Clinging jellyfish (Gonionemus vertens) are now clinging and pulsing safely behind glass as The Maritime Aquarium becomes one of the few aquariums in the country to display the species. Guests will find them as a new addition to the special “Living Lights” exhibit, which features creatures with the unique ability to make their own light and glow in the dark.

While clinging jellyfish do emit green light around the edge of their bodies, they’re more infamous as an invasive species in the region with an especially painful sting. Beachgoers in New Jersey (in 2018) and Rhode Island (in 2019) have been hospitalized after unfortunate encounters with the little jellies.

Maritime Aquarium/contributed photo

Clinging jellies are now one of 16 species of jelly displayed or cultured in The Maritime Aquarium. Guests can enjoy jellies in a variety of mesmerizing presentations, and can even safely touch one species and also observe how the Aquarium produces its year-round supply.

“Our operation in growing and caring for jellies is one of the best in the country, and it’s exciting to be able to add yet another species to our collection,” said Barrett Christie, director of Animal Husbandry. “More importantly, clinging jellies have inserted themselves back into the picture here in New England waters, and it’s good for people to know their story.”

Clinging jellies are small and clear. Their only markings are the fluorescent proteins on the rim of their body, or “bell,” which is bisected by an orange-brown X (their stomach and sexual organs). As many as 80 tentacles extend from the bell, and these have sticky pads that help the animal adhere to seagrasses and seaweeds – hence the name, clinging jellies.

Because they’re small and clear, seeing them in the “Living Lights” exhibit requires a little patience. That they can be hard to see also is what makes them dangerous to anyone who unsuspectingly wades into their world. Symptoms of being stung reportedly can range from mild discomfort and a rash to severe pain, including respiratory and neurological problems worthy of hospitalization for three to five days.

Fortunately, beach-goers who stay on the beach aren’t likely to encounter clinging jellies.

“Clinging jellies survive in calmer, sheltered waters full of seagrasses, not in ocean surf, so – as long as you stay in posted swimming areas and avoid areas with seagrass – your chances of being stung by a clinging jelly are pretty slim,” Christie said.

There was no chance of being stung by a clinging jelly for much of the 20th century in America. They disappeared on the East Coast after an eelgrass die-off in the 1930s, and a variety that lives in the Pacific Northwest seems to be harmless to humans. But in 1990, clinging jellies with the potent sting – native to Russia and Japan – showed up back on Cape Cod. Since then, those clinging jellies have been discovered in clusters from southern Maine down to northern New Jersey.

Maritime Aquarium/contributed photo

In Connecticut, clinging jellies seem to be found mostly in eastern Long Island Sound, around Groton and Stonington.

Within the Aquarium, aside from the recent addition of clinging jellies, the “Living Lights” exhibit features another species of luminescent jelly – crystal jellies – as well as flashlight fish, pinecone fish, a scorpion, chain catsharks and more. The special exhibit opened in June and runs through December. It’s included with Aquarium admission.

Learn more about exhibits, public cruises, virtual programs and COVID safety measures – and reserve your required advance tickets – at

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