Piss Shark!
An elderly inuit woman finds herself with head lice. She knows what to do. When she was little, her mother taught her to wash her hair with urine to get rid of them. She did and she dried her hair with a cloth. The cloth tumbled away in the wind and landed in the ocean. This is the legend of Skalugsuak, the Greenland Shark.
Why would they say that? The flesh of the greenland shark is full of urea, a metabolite found in urine. They reek of it! They also are full of Trimethylamine N-oxide, which stops the urea from poisoning the shark. Together, these chemicals allow the shark to live at great depth and in extremely cold water. Both chemicals are extremely toxic at these levels, but the Inuits and the Nords needed to eat. They'd take their stinky shark meat and bury it outside for weeks, letting microbes break down the nasty toxins. Then they'd dig it up and hang it to dry for months. The end product is called Hákarl and it still smells like piss.
Now the eating of sharks is already controverial, and even more so here. Greenland sharks are thought to take 150 years to reach sexual maturity. They're thought to live to be 400 plus years old. We think they grow between .5-1cm a year and the largest one we've caught was 6.4 meters long. If they slow in growth as they get older, there's no telling how old that shark was! Their pregnancies (they give live birth) could take 18 years each for a litter of 10 pups. There are plenty of trees that will die of old age before these sharks. It's kinda ridiculous we're eating them when we can't even study them.
What we know about greenland sharks is limited due to their habitat. They live in extremely deep and or cold water, places we usually aren't. What we do know about them is from recatching the same ones or interestingly radiocarbon dating their eyes. Neither are super precise but from what I understand, they were able to determine which sharks were fully grown before we started nuclear testing and make inferences off of that. Though it's easiest to find them in shallow arctic water, they've been seen in deep water off the coast of North Carolina and caught of the coast of Belize.
They swim at about 1-2ft per second. With their slow speed, the list of things we've found in their stomachs is remarkable. They mainly eat fish and seals, which is already impressive when you barely move. We've found the normal stuff like squids, jellyfish, sea urchins, and crabs. But then you get into birds, deer, moose, polar bears, dolphins, whales, and a horse? The comforting answer would be that they're scavengers with a great sense of smell. But maybe their slow speed really does make them sneaky enough to nab a seal in the dark.
Almost all greenland sharks have this bug eating their eyes. These are called Ommatokoita elongata and that's their favorite thing to do! It's a copepod that digs its claws in the eyes and starts eating. Mini animal review:0.2/10. Not ecologically relevant and it sucks!! Sometimes the sharks go blind but they mainly live in the dark so it's kinda chill.
The longest living vertebrate is nothing to baulk at. Sharks are older than trees and this shark is lives longer than many trees. You think about all the things that have happened in the past 400 years and a shark has lived through it all, unaware of the news. We protect old trees, old buildings, old books, old everything, but we eat the shark? I don't like it. The Greenland Shark needs more respect. In the same breath, I did call it a piss shark so idk. I think calling it names is a lot less severe than killing it. It's a very chill, slow-lane kinda dude and I want to know more about it.