Greenland shark now oldest living animal with backbone


They estimated that the gray shark, part of the species named after Greenland, was born in the icy waters roughly 400 years ago, and died only recently. That conclusion puts the entire species at the top of the longevity list.



The oldest of the Greenland sharks examined was nearly 16.5 feet long (5 meters) and estimated to be 392 years old when it was caught around four years ago. But that calculation comes with a huge margin of error — plus or minus 120 years — due to the newness of the dating technique, said Nielsen, a marine biologist at the University of Copenhagen.


"It's an estimate. It's not a determination," Nielsen said. "It is the best we can do."


Joao Pedro Magalhaes, a University of Liverpool aging researcher, said because the study is based on an indirect measurement he wouldn't necessarily concentrate on exact numbers, especially when they exceed 400 years, where the upper end of the margin of error goes.

"But the study is convincing enough for us to say that these animals live way longer than human beings and possibly longer than any other vertebrate," said Magalhaes, who runs the longevity database and wasn't part of Nielsen's team.


While not surprised that Greenland sharks live a long time, "I'm really shocked by the magnitude of that longevity," wrote Christopher Lowe, director of the shark lab at California State University Long Beach. He wasn't part of the study, but praised it as creative and compelling.

Greenland sharks love cold water — preferring temperatures near freezing — and are all over the Arctic. The cold water and the slow metabolism that comes with it might have something to do with their long lives, Nielsen said. Lowe, in an email, said "the rule of thumb is deep and cold = old when it comes to fishes."

"I don't know why they get as old, but I hope someone will find out," Nielsen said.

For the age estimates, he uses a complex and indirect system that combines chemical tracking, mathematical modeling and growth measurements. He focuses on the shark eye lens. Those form while the shark is still developing inside the mother's uterus and measures of carbon in them won't change after birth, so it gives a good, rough sense of when the shark was born.

National Oceanic and Atmospheric Administration shark expert Allen Andrews said the dating method "is novel and is likely robust" but he said there are still a number of uncertainties.





Follow Seth Borenstein at and his work can be found at