Danish scientists have discovered the oldest living vertebrate on the planet: a shark ( Somniosus microcephalus ) that could be up to 512 years old.
The findings were published in an article in the prestigious scientific journal Science.
From 272 to 512 years old
These sharks live in the North Atlantic and the Arctic seas, from eastern Canada to western Russia. Its growth rate is extremely slow, about 1 centimeter per year.
So when the researchers found a 5-foot female, it was clear that she was to have a few centuries of life.
Scientists used radiocarbon dating to study this animal’s ocular lenses and 27 other greenland sharks, and it was revealed that the oldest (the large female) was probably about 392 years old.
As there is a chance of error in the analysis, the actual age of the shark can vary between 272 and 512 years.
Until now, determining the age of this species was a very difficult task.
In some fish, scientists examine ear bones, called otoliths, which show a pattern of concentric rings when sectioned. They can be counted as the rings of a tree. Sharks are harder, but some species, like the great white shark, have calcified tissue that grows in layers on the bones of their backs and can also be used to date animals.
Greenland shark, on the other hand, is very soft and has no deposits of layers that can be counted. So the team needed to find an alternative.
“The lens of the shark’s eye is composed of a specialized material and contains proteins that are metabolically inert, meaning that after the proteins have been synthesized in the body, they are no longer renewed. So we can isolate the tissue that was formed when the shark was a pup and make radiocarbon dating, “said Julius Nielsen, a marine biologist at the University of Copenhagen and lead author of the study, for the BBC portal.
Probable age: 400
Most of the 28 sharks studied died after being caught in fishing nets collaterally. Using the radiocarbon technique, the researchers established that the oldest was about 392 years old.
Because radiocarbon dating does not produce accurate dates, the animal could have been as “young” as 272 or as old as 512. But it was probably somewhere in the middle, then about 400 years old.
That means he was born between the years of 1501 and 1744, and could have been alive when Galileo Galilei was still mapping the cosmos. In any case, I was already swimming in the oceans when Dom Pedro shouted the independence of Brazil on the banks of the Ipiranga River.
The oldest ancient vertebrate in the world was a whale estimated in 211 years.
If the invertebrates are brought into the competition, a 507-year-old mollusk named Ming holds the title of the world’s oldest animal.
This means that, even at its youngest possible age, the shark still has to be considered the oldest vertebrate, and, at the highest possible age, even Ming passes.
Sexual maturity and species conservation
Incredibly, the average age of the sexual maturity of greenland sharks is 150 years. According to the researchers, this has consequences for the conservation of the species.
Due to their extreme longevity, the animals may still be recovering from the overfishing that occurred before World War II.
At the time, livers of greenland sharks were used to make engine oil, and they were killed in large numbers until the emergence of a synthetic alternative.