Holly Horner was walking along the beach in Brigantine last week when she encountered a creature whose existence in New Jersey is practically unheard of.

It was a blue button, a jellyfish-like animal that is shaped like a disc ringed with a mane of deep blue and turquoise tentacles. They're only a few inches wide and not regarded as especially dangerous to humans.

“It’s not something I've ever seen before and I've been walking down that beach since I was 10 years old. I'm 55 now," Horner, a professional wildlife photographer from Egg Harbor, told the Asbury Park Press.

Paul Bologna, an associate biology professor at Montclair State University and New Jersey's go-to expert for all things jellyfish, said he's never heard of these tropical creatures washing up on the Jersey Shore until last week.

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It's likely they were carried north to New Jersey by Hurricane Florence, which slammed into the Carolinas last month, Bologna said.

Suzanne Schenker stumbled upon another specimen during a low tide in Beach Haven last week.

A resident of New Hope, Pennsylvania, Schenker was near her family's beach home when she found the blue button. She told the Press, "I just wished that I'd known how special it was" so she could have preserved the remains for researchers.

Bologna doesn't expect them to last long in our less hospitable waters.

"Most likely they will all die off when the water temperature drops, so they may hang around for a few more weeks," Bologna told the Press this morning. "In general, they are not dangerous, but like all 'jellyfish' they do have stinging cells so caution is always the best bet."

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Bologna puts quotes around "jellyfish" because the blue button is a colony of hydrozoans and not a jellyfish in the true sense. The blue button is not one animal but a collection of lifeforms, each with its own individual responsibilities — reproduction, feeding, etc.

The Portuguese man o' war, which sometime float into New Jersey waters, is another example of a colonial hydrozoan.

The pesky clinging jellyfish is also a hydrozoan. Unlike the blue button, this visitor isn't going anywhere and its sting is significantly more savage. Watch the video at the top to learn how to treat their agonizing stings.

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Russ Zimmer: 732-557-5748, razimmer@app.com, @russzimmer