A few years ago, the domestic media reported a study abroad, a scientific research team measured the lifespan of a Greenland shark as 392±120 years old (272 years old - 512 years old), is the longest known vertebrate. For a time, the Greenland shark, an originally lesser-known shark, instantly became famous. Articles about it are all over the Internet, basically revolving around its age.
Judging from some articles and videos published by the self-media, they take it for granted that the shark is still alive.
For example, this kind of "this shark lived from the Ming Dynasty to the present"▼
And then there's this —"a shark forgotten by death."
There's even this one— "a 512-year-old shark is still alive."
Seeing this reminds me of a famous saying that some people are dead, and he is still alive. It seems that this famous saying applies equally to the animal kingdom.
This well-known shark has already "dedicated" itself to science.
It is estimated that the media report did not make it clear, resulting in many people not knowing, the age of this long-lived shark, by plucking its eyeballs, with carbon 14 dating measurement lens nucleus.
The team obtained 28 Greenland sharks that were overfished or accidentally caught in the waters off Greenland in 2010-2013, all fatally injured and euthanized for research. Their body size was measured and ranged in length from 81 to 502 cm. The eyeballs are plucked out to determine age. Julius Nielsen of the University of Copenhagen in Denmark led a team to date carbon-14 with the lens nucleus in the shark's eyeball, and learned that the largest greenland shark had an age range of 392±120 years (the carbon-14 dating method could not be accurate to a certain year, only a general range), and the 2016 research was published in science magazine and also appeared on the cover.
(Bycatch: When catching some target aquatic products, you inadvertently catch other species, as if you wanted to cast a net to catch fish, and then caught the crabs.) Bycatch: Mistakenly catching an animal, mistakenly catching an animal)
The Greenland shark is between 272 and 512 years old, and even at its lowest age of 272, it is the longest-lived vertebrate known, surpassing the 211-year-old bowhead whale.
The original paper, titled "Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus)," translates to this: Eye lens carbon 14 dating shows the lifespan of the Somniosus microcephalus for hundreds of years.
Why is it possible to know the age of sharks with carbon-14 dating?
Carbon-14 dating has previously been used to measure the age of cetaceans, the first time it has been used in sharks.
The original paper gave the research principle, which was roughly stated: using radiocarbon dating technology (C14), the age was estimated from the chronology of the lens nucleus. In vertebrates, the nucleus of the eye lens consists of metabolically inert crystal proteins, and the center of the crystal proteins (i.e., the embryonic nucleus) is formed during prenatal development. This tissue retains the proteins synthesized at about 0 years of age: a feature of the lens found in vertebrates that are difficult to age. Our shark chronology was constructed by measuring isotopes in the lens nuclei of 28 female specimens (total length 81 to 502 cm), and we used radiocarbon dating techniques (C14) to estimate age and stable isotopes...
There are a lot of professional terms in the back, even the translation software can not be translated smoothly, and there is a suspicion of word count when written, and those who are interested will understand it themselves.
The full length (TL) and age range (Age range) of the Greenland shark in the study, 3 smaller ones were not listed.
So, the longevity shark of this hot network died long before 2013, and like the 507-year-old Arctic clam that was pried to death, it is considered to be a "sacrifice" for science.
Finally, to add some basic information about the Greenland shark.
The Greenland shark is distributed in the North Atlantic Ocean, concentrated in the northern, western European and eastern Parts of North America, with a maximum habitat depth of 2647 meters.
The Greenland shark is huge, with wikis saying it can reach a maximum of 7.3 meters and weigh more than 1400 kilograms.
Their tour speed is very slow, usually only 1.22 km/h, and the fastest cruising speed is only 2.6 km/h.
They are also almost blind, and a copepod called Ommatokoita elongate parasitizes their eyeballs, nibbling on the cornea of their eyes until they become blind. But Greenland sharks don't need vision in the dim deep ocean, they rely on smell and hearing, so parasitizing the eyeballs doesn't reduce greenland shark life expectancy and predatory ability.
Despite their slow swim, greenland sharks are predatory sharks that feed mainly on fish, with documented fish prey including smaller sharks, rays, eels, herring, cod, salmon, rosefish, duparabs, roundfins, wolffish and flounder. The stomachs of Greenland sharks have also found the remains of polar bears, seals, moose and reindeer, some of which may be scavenging.
Greenland sharks will slowly approach their prey, and then open their large mouths to create a suction force to suck small prey into their mouths, so indigested intact prey has been found in the stomach of Greenland sharks.
The Greenland shark grows at a rate of only 0.5-1 cm/year and has a body length of nearly 4 m to reproduce, taking 156±22 years. Pregnant female sharks leave embryos in the body for a gestation period of up to 8-18 years.
Greenland sharks are rich in trimethylamine oxide (TMAO), which can be poisoned when eaten directly, but Icelanders who lack food will still turn them into dark dishes through a series of treatment methods, dark dishes that are worse than canned herring.
The Greenland shark is assessed as vulnerable (VU) by the IUCN, along with giant pandas and snow leopards, and little is known about its survival.