To talk about the longest-lived animals in nature, most people will think of the phrase "80,000 years turtle of the thousand-year king", and will think that animals such as turtles can live the longest.
Indeed, for example, the Aldabra tortoise, the oldest has lived for 256 years, but the animal that really has the longest life, now research has found that it is really not a turtle.
It looks like a long-lived look
An animal forgotten by death
In people's impressions, sharks are mostly as ferocious and brutal as great white sharks. Among them, there are also "strange-shaped" sharks such as hammerhead sharks. It's hard for anyone to associate sharks with longevity.
Hammerhead shark with a flat head
But in the far cold Arctic depths, scientists have found such a shark, and after research, the longest-lived shark has probably survived for 512 years.
Why is this number so precise? That's thanks to Julius Nielsen at the University of Copenhagen.
The true face of the "old birthday star"
The researchers found that the particularly long-lived Greenlandic shark's eyeball contained a special protein. Once synthesized in sharks, this protein is not broken down or renewed. Therefore, it can be said that how long this protein has existed, how long the shark lives.
In 2016, researchers measured the lifespan of 28 female Linglan sharks. The team isolated the tissue formed when the shark pups were formed and performed radiocarbon dating (a method of dating items containing organic material using the radioactivity of carbon's isotope 14 C) to determine their lifespan.
International paper on this research
However, because this measurement method has a certain margin of error, it is not possible to measure a very specific time. Among these sharks that were aged, the longest living shark was 392±120 years old, that is, its age was 272 years old, and the maximum could reach 512 years old.
"Old birthday" and divers
Therefore, many people see that sharks can live up to 512 years, which is not wrong.
Although there is an error of more than 100 years, it has also proved that the lifespan of this shark is at least close to 300 years, and it can indeed compete with the longevity champion of the turtle, so foreign countries will call them "animals forgotten by death".
Greenlandic sharks swim to the side of the boat
Sharks are also rotten
What is the secret of Greenland sharks to longevity?
The first is because their metabolism is slow. The heart beating speed of Greenland sharks can even beat only 5 times a minute, while the heart of normal adults beats between 60 and 100 beats per minute.
Because their metabolism is extremely slow, the renewal rate of cells in their bodies is also very slow.
Its unassuming Greenland sleeping shark
Greenland sharks are also very slow to grow, not to mention that adult sharks can reach a maximum body length of 7 meters, but they only grow an average of about 1 cm per year. With such a slow growth rate, it takes a full 150 years for a Greenlandic shark to produce offspring from birth.
Not only do their bodies develop slowly, but these long-lived sharks also move slowly. When in the ocean, they usually move at only about 20 centimeters per second. When people see it, they can't tell whether it's swimming or simply drifting with the current, and many people think they are always sleeping, hence the name "Greenland sleeping shark".
This is a rare time for sleeping sharks to move relatively quickly
The Greenland sleeping shark in the name "Greenland" means that they live mainly in the high-latitude waters centered on Greenland, where water temperatures are very low all year round. Low water temperatures and the fact that they often move up to 2200 meters deep, so sleeping sharks have few natural predators.
Part of their longevity is also due to this low water temperature. At low temperatures, cold stimulates anti-aging properties and anti-aging factors in the organism. To this end, scientists have also experimented with fruit flies: fruit flies living in 21 °C temperatures will live longer than fruit flies living in 27 °C environments.
International paper on how low temperatures make fruit flies live longer
Therefore, the reason for the longevity of Greenland sleeping sharks is slow metabolic rate, cold living environment, lack of natural enemies, lack of movement, and other factors.
Eating the eyes does not affect life
Greenland sleeping sharks are almost as big as great white sharks, but how do they prey on them when they move so slowly? If you only eat some small fish, shrimp or even plankton, it is too much loss of face for sharks, the top predators of the ocean.
The size is really not small
It turns out that Greenland sleeping sharks are still top predators, despite being so lazy. In the stomach of the Greenland sleeping shark, scientists found no less than 25 species of fish in 14 families, including gastropods, cephalopods, echinoderms, cartilaginous fish, teleost fish, and marine mammals.
Among these fish, the Greenland turbot (píng) fish accounts for a large proportion, and it has been found in the stomachs of two-thirds of the sleeping sharks surveyed, accounting for almost one-fifth of the sleeping shark diet.
This fish is a valuable edible fish, with less spines and more meat, and the largest size can grow to more than one meter, belonging to a medium and large prey.
It's this ugly and delicious fish
In addition, sleeping sharks can also prey on marine mammals, mainly seals of various species. These mammals do not appear very often in the stomachs of sleeping sharks, but each head is large, so it occupies about half of the sleeping shark prey.
In addition, some sleeping sharks can even prey on polar bears, the "polar overlords". Although it is not known exactly how slow-moving sleeping sharks eat polar bears, the world's largest bear has indeed appeared in the stomach of sleeping sharks.
Precious photo of sleeping sharks preying on seals
According to scientists' efforts, the reason why sleeping sharks can prey on so much prey is inseparable from a species of ráo-footed animal that parasitizes on their eyes.
Copepods are small invertebrate crustaceans that usually survive in plankton or parasitic ways. After approaching the sleeping shark, this parasitic animal will eat the cornea of the sleeping shark, eat them blind, and then hang on the sleeping shark's eyes to live.
A pepepod that always looks strange
Although blind, it is actually a good thing for sleeping sharks. First of all, sleeping sharks usually move in the sea at a depth of one or two kilometers, and the ocean at this depth is basically dark, and it has little effect on whether there are eyes or not.
Animals living in the deep sea are basically difficult to use, at most they can feel the change in light. This small animal parasitic on the eyes of the sleeping shark will glow on its own, which will make other deep-sea animals think that they are prey that can be preyed, and will naturally be attracted to the past, and the end can be imagined, all become the food of the sleeping shark.
Small animals parasitizing on the eyes of sleeping sharks
Therefore, no matter how lazy the Greenland sleeping shark is, it basically does not worry about eating and drinking, and it is not uncommon to become an "animal forgotten by death".
A new Grim Reaper has appeared
This was the end of the story of the Greenland shark, but in 2006, the name of the Greenland sleeping shark appeared on the Red List of Threatened Species in the World.
IUCN website
To say the reason, in fact, it is also a cliché - human indiscriminate hunting and killing.
In Greenland, the main distribution of Greenland's sleeping sharks, the indigenous people here have always had the habit of eating shark meat, and they cook shark meat in one way and make one of the world's smelliest foods.
In a small white bowl is marinated shark meat, which needs to be eaten with spirits and bread
Shark meat is actually not delicious, because the shark excretory system is different from many animals, they do not have a bladder to store urine, will excrete the urine produced by metabolism through the skin, so shark meat and skin have a special smell of urine.
No matter how it is handled, the strange taste in shark meat is also difficult to remove, so people simply do not clean up, but first cut the shark meat into pieces and marinate, ferment for three months, and then hang it to dry for about half a year, and finally cut the shark meat, although it looks white and tender, but it is said that the smell is strong to the spicy eyes.
Marinated shark meat being dried
Therefore, outsiders generally do not like to eat this "specialty", but for locals, it is an indispensable "social" etiquette. Eating stinky shark meat with loved ones is a grand ritual that can only be "enjoyed" during the New Year and holidays.
Locals say: The land we live in has been short of food since ancient times, and eating shark meat is to remember the difficulty of survival of our ancestors and remember where we came from.
Sleeping sharks caught by locals
Of course, making this traditional food does not pick the species of sharks, and when the technical means are not developed enough, there are not enough organisms in high-latitude areas such as Greenland, and they can only catch what to eat.
Such small-scale fishing will also have little impact on sleeping shark populations. Maybe not only do we not think that this is ecological destruction, but we will also sing the praises of this is a magnificent chapter of mankind's struggle against nature to survive.
On the other side of the globe, Japan is killing whales for similar reasons
However, Greenland is now part of the Kingdom of Denmark, Denmark is a veritable developed country in Europe, shark-related industries have always been important in this country, after the development of science and technology, the formation of large-scale commercial fishing. (For the commercial value of sharks, you can click here to view our previous popular science article)
Shark skin, flesh, bones and internal organs have high commercial value, and although commercial fishing for Greenland sleeping sharks ceased in 1960 and the government increased fisheries subsidies in the 70s, it is not surprising why Greenland sleeping sharks still appear on the Red List of Threatened Species more than 30 years after these conservation measures have been implemented.
At the end of the article, to borrow a famous advertising slogan: no sale, no killing.