Updated August 13, 2016 at 12:00 am
Greenland sharks would be more long-lived marine vertebrates
Washington. AP In the cold waters of the Arctic, a resident of the depths has been lurking for centuries. Scientists estimate that this female Greenland shark is the oldest living vertebrate on the planet.
They estimate that the gray shark, part of a species that takes the name Greenland, born in waters icy approximately 400 years ago and recently she died. The conclusion puts the species at the top of the list of longevity.
Using a new physical dating technique, an international team of biologists and calculated the age of 28 female sharks Greenland based on tissue in her eyes.
Eight sharks were probably 200 years or more, and two probably date back more than three centuries, according to a study published in the journal Science .
Long existence. So far, the record belonged to an Arctic whale that reached 211 years of age, according to Julius Nielsen, author of the study and Anage, a database animal longevity.
the oldest Greenland sharks examined had about five meters long (16.5 feet) and a calculated at 392 years old when he was caught about four years ago. But that calculation comes with a huge margin of error-more or less 120 years because of the novelty of dating technique, Nielsen, a marine biologist at the University of Copenhagen said.
that means that the shark was probably born sometime between 1500 and 1740, with 1620 the most likely year of birth
” is a calculation; is not a determination, “said Nielsen. “It’s the best we can do.”
Even in the lowest part of the margin of error, the shark would be 272 years old when he died, and would be the oldest living vertebrate added Nielsen. Other experts agreed.
Joao Pedro Magalhaes, a researcher of aging at the University of Liverpool, said that because the study is based on an indirect measurement, he would not focus necessarily in exact figures, especially when over 400 years, where the upper margin of error is.
“But the study is compelling enough to say that these animals live much .ad-main – – more than humans and, perhaps, more than any other vertebrate “Magalhaes, who manages the database longevity and was not part of the team said Nielsen
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Other ‘oldies’. Some invertebrate animals live longer. There is no record of an oyster who lived 507 years and it has been said that two different species of marine sponges survive 15,000 and 1,500 years.
Although it is not surprising that Greenland sharks live long time, “I’m really surprised by the magnitude of that longevity,” wrote Christopher Lowe, director of the Laboratory of Sharks California State University, long Beach campus. He was not involved in the study but called it creative and persuasive.
Greenland sharks love the cold waters they prefer to temperatures near the freezing-point and all are in the Arctic . Cold water and slow metabolism that leads might have something to do with their long lives, Nielsen said. Lowe said in an email that “deep and cold = old, when it comes to fish. “I do not know why they reach such an advanced age, but I hope someone finds out,” said Nielsen.
To calculate age, he uses a complex and indirect system, which combines chemical tracking, mathematical model and growth measures.
focus on the crystalline lens of the eye of the shark. This is formed when the shark is still developing in the womb of the mother and the measures carbon in it do not change after birth, so it provides a good clue as to when he was born the shark.
Allen Andrews, shark expert at the National Oceanic and Atmospheric Administration, said the dating method “is novel and robust” but noted that there are still doubts.
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