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11 Terrifying Things You Never Knew About the Ocean
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I realize the world’s oceans provide half of the oxygen we need to survive as a species, but the these eleven undersea creatures and facts are so terrifying, I sort of want to get rid of the oceans anyway.

There’s a jellyfish that’s literally immortal

There’s a jellyfish that’s literally immortal
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Like just about everything under the ocean, jellyfish are worse than you realize. Their bodies (if you can call them that) are almost all water. They don’t have brains, eyes, or hearts. They’re not even technically fish. They’ve been around for over 500 million years, just randomly killing things that touch their poisonous blobulescences. Poison from the box jellyfish seen here can stop a fully grown person’s heart in five minutes, and the Turritopsis dohrnii jellyfish is literally immortal.

The “goblin shark” exists

Remember how the Xenomorphs in the Alien movies have a second set of jaws and teeth that shoot out of their mouths to threaten Sigourney Weaver? Goblin sharks actually do that. Their jaws are protrusible; they project out of their face so their nail-like teeth can catch unlucky prey. These ugly, translucent horrors can grown up to 16 feet long, but luckily, they live in such deep parts of the sea that they don’t pose a threat to humans. Yet.

There’s a parasite that becomes its host’s tongue

There’s a parasite that becomes its host’s tongue
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There is no better argument for the elimination of nature than Cymothoa Exigua. Sometimes called the “tongue-eating louse,” these soggy parasites enter the gills of an unsuspecting fish (like Dory from Finding Nemo) and attach themselves to their host’s tongue. They divert the blood supply until the tongue withers and dies, then they latch on to the tongue-stump and just hang out in someone else’s mouth, drinking blood and fish mucus and not paying rent.

The worst part is, the host fish don’t die. They have to live and find a way to cope with the fact that their tongue is now another creature. It’s a natural organ-transplantation, and it’s very wrong and bad and must be stopped. The only positive thing about Cymothoa Exigua is that they change their sex from male to female, which is cool.

The sharks are planning something

The sharks are planning something
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The White Shark Café is a tiny area of the Pacific ocean halfway between Baja California and Hawaii where great white sharks gather. No one knows exactly why these usually solitary hunters get together here, but they travel, on average, for 100 days to do it. Scientists think they’re after a source of food too deep underwater for our satellites to detect, but I think they’re planning something.

Unrelated cool fact: A group of sharks is called a “shiver.”

Parts of the ocean can boil you alive

Parts of the ocean can boil you alive
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The deep sea floor is riddled with “black smokers,” mineral “chimneys” formed from hydrothermal vents shooting super-heated water into the cold depths. The water can be over 700 degrees Fahrenheit, so it would boil your flesh if you got near it, but there are entire ecosystems that thrive on these vents. Unlike just about everything else alive, the vent-creatures don’t rely on sunlight to survive. Some of them don’t need oxygen either. Destroying all life in the oceans is going to be a challenge.

We’ve only explored about 10% of it

We’ve only explored about 10% of it

Maybe the scariest thing about the undersea world is how little we know about it. Because it’s so inhospitable, we’ve only explored maybe 10 percent of the ocean, so we don’t really know what’s down there. It could be anything. Perhaps there is a race of intelligent sea creatures for whom the earth’s surface is as alien as the bottom of the sea is to us. Their technology would be utterly foreign to us, as it wouldn’t be based on fire, so who knows what they can do. Maybe they’re posting to their underwater websites about the horrors of the things that live on the surface at this very moment.

Nothing about octopuses makes sense

Nothing about octopuses makes sense
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We don’t really know what’s going on with octopuses. We know they have eight arms, sure, but what are they about? They have big brains. They change color. They live in cities. They use tools (including weapons and armor). They even dream. They might have come from outer space. We know octopuses have a kind of intelligence, but we can’t really test it because octopus minds are so different from our own. We don’t even know why they’re intelligent. Octopuses don’t make any kind of sense. We should probably eat as many of them as we can.

It took Donald Crowhurst and we don’t know why

It took Donald Crowhurst and we don’t know why
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The story of British sailor Donald Crowhurst should serve as a cautionary tale to all land-based mammals. In 1968, Crowhurst was competing in an around-the-world solo yacht race. His boat quickly took on water, but he didn’t call for help. Instead, he sailed on in his sinking ship, falsifying his positions on the radio to make it look like he was setting a record pace. While everyone thought Crowhurst was winning the big yacht race, in reality, he was sliding into madness, drifting in the middle of the sea, spending all day scribbling his mad “philosophical” theories in notebooks. They found his boat, but never found his body.

The hagfish lives there, and it’s nature’s most disgusting animal

The hagfish lives there, and it’s nature’s most disgusting animal

Hagfish are terrible. They spend their lives producing milky, fibrous mucus that they expel to slip away from or suffocate predators. These things produce so much slime it’s ridiculous. It’s said that a hagfish can fill a five-gallon bucket with slime in minutes. They “sneeze” to clear their nostrils and to not die of their own disgustingness. They tie themselves into knots so the slime doesn’t drip onto their heads. All day long: Slime, slime, slime.

The slime is bad, but how they eat is worse: They survive by burrowing their bodies, mouth first, into the flesh of dead or dying animals and eating them from the inside out.

They also have skulls but no skeletons, which makes no sense.

There’s an ongoing war between sperm whales and giant squids

There’s an ongoing war between sperm whales and giant squids
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The giant squid is huge. There’s no gravity deep underwater, so there’s nothing to prevent these creatures from growing. Giant squid eyes are the size of dinner plates. Their penises are a yard long.

But there are even bigger squid under the ocean: The colossal squid can be as long as a three-story building is tall.

Luckily, sperm whales are also huge, and they love to eat squid. Right now, under the sea, death-battles of these gargantuan animals are being waged. This should not be allowed to continue.

There’s a parasite called phronima that lives in its victim’s corpse

There’s a parasite called phronima that lives in its victim’s corpse
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The goblin shark isn’t the only sea-creature to inspire the aliens in the Alien movies; the phronima parasite is the inspiration for the “chest-bursting” scene in the original flick. These tiny parasites live by slicing open the bodies of plankton and moving in. From there, they devour their host’s soft tissue and live inside the hollow corpse of their victim, laying eggs and raising their children in their corpse home. It’s all too much to think about, to be honest.