But recently, larger pinkish-purple jellyfish have been turning up at the Jersey shore.
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They're called "mauve stingers."
One of them was found by Natali Megill and her kids in Manasquan this week.
"The kids and I were investigating it. Poked at it a couple of times, made sure nobody got stung by any of the tentacles," said Megill, of Wall Township, N.J.
And it's a good thing - this species is known for its powerful sting.
As more and more people posted photos and videos on the Facebook group New Jersey Jelly Spotters, it caught the eye of Paul Bologna.
He's the director of Marine Biology and Coastal Sciences at Montclair State University.
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"It's native to our area but it's extremely rare. It tends to be something that might be offshore," said Bologna.
He says these jellyfish are more common in Mediterranean waters, and say a number of factors could be bringing them here.
"We had a lot of upwelling along the coastline and now we've got this warm water and weather patterns with these very consistent winds that are coming offshore," said Bologna.
He says he's never seen this many along the Jersey shore before.
He advises while they're tempting to look at, they're intensely painful.
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"They're absolutely beautiful but they really do have a pretty potent sting," said Bologna.
He says most of the sightings have been shore points in Monmouth and Ocean counties, but he's heard a few reports of mauve stingers in South Jersey, too.
Bologna says he was stung by a mauve stinger a few years ago and he said it was one of the worst stings he's experienced.
A tip if you get stung: white vinegar can help provide some relief. Bologna says it neutralizes any stinging cells that may be left in your skin.