8 Times Jellyfish Were The Absolute Scariest Creatures On Earth

As a child growing up near the Gulf of Mexico, I had a conflicted relationship with jellyfish. On the one hand, I thought jellyfish were the scariest creatures ever—stealthy, wobbly aliens that could sting you before you even saw them. On the other hand, I sort of loved them for their strange, hypnotizing beauty. My hometown is home to the Texas State Aquarium, which houses a whole room of “floating phantoms,” with tank after tank of the slowly undulating, mesmerizing creatures, lit so that I could see their neon colors standing out from the dark. Even now, when I visit the aquarium, I like to sit in that room and imagine what it would be like to sleep in there, surrounded by their ghostly presences.

As beautiful as they can be, however, jellyfish are also completely terrifying. They are very old (to the tune of half a billion years), very resilient, and incredibly abundant. Lisa-Ann Gershwin, author of Stung! On Jellyfish Blooms and the Future of the Ocean , warns that jellyfish are taking over our oceans. Their numbers are increasing for a variety of reasons, including the fact that overfishing and pollution have lowered the number of natural competitors and predators of jellyfish, and climate change has allowed jellies to extend their territories. They pose a very real problem to other ocean inhabitants and humans alike. Depressingly, Gershwin is doubtful that the situation is salvageable. Jellyfish may be beautiful, but they’re a menace.

1. That time a swarm of jellyfish stung 400 people

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In August of 2014, more than 400 beach goers near Daytona Beach and New Smyrna Beach in Florida were stung when a huge swarm of jellyfish moved toward the shore. Fortunately, no one was gravely injured, but having such a massive attack all at once must have been seriously scary.

2. That time a box jellyfish did… anything, really

Box jellyfish are the most toxic of all jellyfish and are regarded as one of the most dangerous species on Earth. Their tentacles extend up to 10 feet, and their venom causes so much pain that humans that have been stung risk going into shock and drowning or dying of heart failure. In 2014, a 5 year-old boy from France was killed by a box jellyfish while swimming in the ocean near Thai resort island Koh Phangan.

3. That time a group of jellyfish took out a 10-ton fishing boat

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In 2009, a Japanese fishing trawler capsized as its crew tried to pull in nets of dozens of Nomura's jellyfish. These jellies are massive, growing up to 2 meters in diameter and weighing about 450 pounds each.

4. That time jellyfish were IMMORTAL

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Is there anything more terrifying than the idea of an immortal, vampire jellyfish? The turritopsis dohrnii isn’t quite Dracula yet, but this small jelly is close. It’s the only known species that is capable of reverting to a younger form of itself. When the mature turritopsis dohrnii reaches near-death, it reverts to a polyp (younger) form, and then regrows into an adult again. Watch the video above for a more detailed account of how this works.

5. That time a jellyfish caused “Irukandji syndrome”

Irukandjis are small relatives of the deadly box jellyfish, measuring only about a centimeter across. Their small bodies house a deadly predator; a single sting can cause “Irukandji syndrome” in a human. Tim Flannery describes the syndrome in The New York Review of Books:

It sets in twenty to thirty minutes after a sting so minor it leaves no mark, and is often not even felt. Pain is initially focused in the lower back. Soon the entire lumbar region is gripped by debilitating cramps and pounding pain—as if someone is taking a baseball bat to your kidneys. Then comes the nausea and vomiting, which continues every minute or so for around twelve hours. Shooting spasms grip the arms and legs, blood pressure escalates, breathing becomes difficult, and the skin begins to creep, as if worms are burrowing through it. Victims are often gripped with a sense of “impending doom” and in their despair beg their doctors to put them out of their misery.

Um. OH MY GOD

6. This insanely massive jellyfish

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The world’s largest jellyfish is the lion’s mane jellyfish, which can grow up to 8 feet in diameter, with tentacles that extend up to 60 feet. Unlike the box jelly, the lion’s mane jelly’s stings are not usually fatal to humans. The jelly’s sheer size is shocking, however. In 2010, 150 people in New Hampshire were stung by what was believed to be a single lion’s mane jellyfish that had died and broken up (yes, they can sting you even when they’re dead).

7. That time they got stuck EVERYWHERE

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In a review of Gershwin’s book, Flannery recounts a number of episodes in which thousands of jellyfish got stuck in very inconvenient places. In 2006, the USS Ronald Reagan, docked off the coast of Brisbane, Australia, was disabled when jellyfish clogged its cooling systems. In 1999, thousands of jellyfish were responsible for jamming the cooling system for a major power plant in the Philippines, leaving 40 million Filipinos without power. (The blackout was so sudden that many people suspected a military coup.)

8. That time on Friends when Monica got stung by a jellyfish and Chandler peed on her

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The lesson of this episode is Don’t Pee On People. According to Scientific American, peeing on a jellyfish sting won't help; in fact, “Urine can actually aggravate the jellyfish's stingers into releasing more venom.” So all that trauma was for nothing, Chandler! Nothing!

Images: Getty Images(3); Guido/Flickr; GondwanaGirl/Wikimedia