Scientists have discovered the vertebrate that beats all the previous longevity records. Meet, Greenland Shark, a 21-feet long animal living in the icy cold Arctic waters. Its flesh is poisonous due to the presence of anti-freezing compounds. They are predatory sharks that grow and swim at a lethargic pace.
A recent study published in Sciencemag by scientists from the University of Copenhagen states that this shark is the longest living vertebrate discovered on the planet. The study was led by Julius Nielsen, a marine biologist, and included 28 female sharks captured as bycatch. Nielsen and colleagues estimate that the Greenland Sharks possibly survive for about 3-4 centuries as it grows less than one centimeter every year. Admittedly, this is just a calculated estimate.
“We’re not saying directly that we think the Greenland shark is 400 years old,” Nielsen told. “We’re saying that with 95 percent certainty, it is between 272 and 512 years.”
The scientists have given a wide range of their expected life due to less known information about the mysterious Greenland shark. Its habitat is the polar water, one of the least explored areas in the world. They swim to the depths of 7,000 feet, and most of the submersibles dives don’t reach up to that depth. That’s why the chances of their detailed study are rare and indeed very few.
Another issue is that the Greenland sharks lack calcified tissue, one of the easiest indicators of age. What now? Nielsen and team used the radioactive carbon in the specimens’ eye lenses and carried out a “bomb pulse onset.” This was generated by the cold war nukes and acted as a timestamp to calculate the approximate ages of the sharks.
“This is a different method than normally is applied to estimate the age of fish,” Nielsen said. “The numbers can definitely be improved, and I hope they will be improved in the future, because obviously 240 years of uncertainty is not super satisfying. But we decided that it was enough to, at least, go out and say that the longevity of this animal is measured in centuries.”
Even if we take the lower limit of Greenland shark’s estimated age (272 years), this animal would still be the world’s longest living vertebrate ever. It has broken the longevity record held by the bow-head whale that has a lifespan of 211 years.