Greenland Shark Lives 272 Years, Study Says

     
     (CN) — A shark born decades before the American Revolution holds the new record for longevity in vertebrates by living at least 272 years, scientists announced recently.
     The Greenland shark’s lifespan exceeds the oldest elephant in captivity, Lin Wang, who died at age 86. The official record for longest lifespan among humans is held by Jeanne Louise Calment, a French woman who lived to be 122 years old.
     The shark is the oldest known vertebrate, a large group of animals having a backbone or spinal cord.
     “It kicks off the bowhead whale as the oldest vertebrate animal,” said lead author Julius Nielsen, who noted that bowhead whales can live up to 211 years.
     An Icelandic clam named Ming was the world’s longest living creature before finally being euthanized by scientists at the age of 507.
     Greenland sharks can grow to about 16 feet in length, making it one of the world’s largest carnivores. While scientists knew the Greenland sharks were one of the longest-living creatures — they reach sexual maturity at about 150 years old — they were unsure just how long the sharks could live.
     The team constructed their shark chronology by taking measurements of isotopes — two or more forms of the same element that contain a different number of neutrons in their nuclei — in the eye-lens nuclei from 28 female specimens collected between 2010 and 2013 around Greenland.
     “Our lifespan study is based on the carbon-14 dating of Greenland shark eye lenses. As with other vertebrates, the lenses consist of a unique type of metabolically inactive tissue. Because the center of the lens does not change from the time of a shark’s birth, it allows the tissue’s chemical composition to reveal a shark’s age,” Nielsen said.
     Examining eye lenses has previously led to determining the age of whales, but this is the first time it has been used to estimate the lifespan of a fish.
     Carbon-14 dating is primarily used for archaeological dating, but the incredible lifespan of Greenland sharks led the team to incorporate the technique into their research.
     The study also represents a significant opportunity for the establishment of sustainable management plans for Greenland sharks, according to Nielsen.
     “Greenland sharks are among the largest carnivorous sharks on the planet, and their role as an apex predator in the Arctic ecosystem is totally overlooked. By the thousands, they accidentally end up as by-catch across the North Atlantic and I hope that our studies can help to bring a greater focus on the Greenland shark in the future,” Nielsen said.

Photo: Julius Nielsen

%d bloggers like this: