Six-year-old Margot Pepyne stared into an illuminated tank at the New England Aquarium.
"I like how they look," she said of the jellyfish pulsing through the water. The South American sea nettles in the tank were mostly white, with red Vs arranged in a circle, red tentacles trailing behind.
Pepyne turned to her mom with a question.
"Can you cut off these things?" she asked, pointing to its tentacles.
That would hurt the jellyfish, her mom replied.
"But axolotls grow, like, new stuff on their body," the six year old said.
Several floors above Pepyne and her mother, a jellyfish culture lab holds answers to many of the questions swimming in the inquisitive minds below. Around the lab are tanks with rounded bottoms where jellyfish of all sizes are circulating.
"They have remarkable regeneration," said Chris Doller, who manages the New England Aquarium's changing exhibits and is part of the team that breeds jellyfish for the aquarium's displays and for other aquariums around the world.
"Even some of these long feathery oral arms that you see here," he said, pointing to some of the longer tentacles that jellyfish use to get food. "If they get dropped, they will sort of start to grow back."
News reports this summer have described a surge of red Lion's Mane jellyfish off the coast of Massachusetts. And while there are a lot of very large ones showing up, Doller said it's not all that unusual.
"That is a regular occurrence for this part of the world at this time of year," Doller said. "Some years there's not as many and they don't get as large. And then we have some summers where there just seems to be a lot of them, and it seems to coincide when people are headed to the beach and they may be washed up on the beach. But yeah, they're native to this part of the world."
There's a lot to look at in the New England Aquarium. But the small, illuminated jellyfish tanks are among the most mesmerizing — and they're especially popular with many children who visit.
Visitors, especially children, often have wonderfully direct questions about jellyfish. GBH News collected a few of them during a visit to the aquarium and later asked Doller to answer them.
Another of Margot Pepyne's questions: "How does a jellyfish see?"
When GBH News posed that question to Doller, his answer was clear: They don't.
"Some jellyfish have a very primitive eye," he said. "Not enough to, like, see images. But almost to, sort of, navigate around an obstacle in their way. But for the most part, jellyfish are not capable of sight."
When asked what she'd like to know about jellyfish, 5-year-old Kenessa Bradway responded with a simple but big question: "How they are made?"
That's what Doller focuses on in the fifth floor lab. "The males have sperm, females have eggs," he said. "They spawn in the water when the conditions are right."
That leads to a larval egg, which becomes a polyp on the sea floor.
"The polyps can reproduce asexually, so they can sort of clone themselves," Doller said. "So what started as one fertilized egg plants itself on a rock, may colonize a whole rock of these polyps. Each polyp itself can actually metamorphose and bud off these little swimming jellyfish."
Doller showed off a petri dish encrusted with polyps.
"So each one of those tiny little polyps you see there can produce hundreds and hundreds of jellies."
That happens when the water warms up, which is something the aquarium can take advantage of when producing jellies.
"So we sort of fool them into thinking it's winter [or] it's summer, and we can essentially turn them on and off at will," Doller said. "And we've gotten kind of a good system going so that when we need more jellyfish for some species, we just warm them up and they will start producing these little medusae. And then from there, it's sort of like growing them like plants."
Back in the public area of the aquarium, Envy MacClain said she's a jellyfish fan, despite their most notorious trait.
"I like them and they sting," she said.
Doller explained the stinging is how they catch their food.
"So they're not trying to sting humans, for example," he said. "All the stinging cells that are on those tentacles, that's how they incapacitate their prey."
And how that works is way more complicated and interesting that most people probably realize. They're not just touching people with a chemical that causes an irritation on the surface of your skin.
"If you looked real microscopically at a tentacle, it's sort of lined with these little balloons," Doller explained. "Inside the little balloon is a harpoon. And when it comes into contact with something that it can sting, the harpoon fires out of the tentacle, fires out of the balloon, and has some toxin in it. And it will just sort of inject a little bit of toxin through each little stinging cell."
If you're on the receiving end of that poison harpoon, he said, the best thing to put on the sting is actually vinegar.
Another child visiting the aquarium, Nailah Jackson Fenton, wanted to know how bad stings could get.
"I would like to know, if a person touches one, could they die?"
"The gamut on toxins in jellies is pretty wide," Doller said. "There are some jellyfish in the world that have caused some human fatalities. My guess is it's probably people who were compromised in some way to begin with, much like people are with bee stings."
Because of all that stinging, Doller said he understands why jellyfish have a bad reputation. But, he adds, they're also fascinating — especially when considering they predate the dinosaurs.
"I think that's something to be appreciated," he said. "But I can understand why this animal that has no brain and has no way of avoiding you when you're at the beach develops that sort of reputation. But I think they're pretty cool."
Copyright 2026 GBH News Boston