According to experts, Greenland sharks are now the world’s longest-living animals.
The ages of 28 Greenland sharks were determined using radiocarbon dating of ocular proteins, and one female was believed to be almost 400 years old. A bowhead whale believed to be 211 years old held the previous vertebrate record.
“We had our expectations that we were dealing with a unique species,” lead author Julius Nielsen, a marine scientist from the University of Copenhagen, explained, “but I believe everyone performing this research was really startled to hear the sharks were as ancient as they were.”
Greenland sharks are enormous, reaching lengths of up to 5 meters. Despite this, they only grow 1cm every year. They may be observed swimming slowly in the North Atlantic’s chilly, deep waters.
The researchers think the creatures attain sexual maturity when they reach 4 meters in length. And, based on this new, extremely long age range, it appears that this does not happen until the animals are around 150 years old.
The research was made feasible in part by atmospheric thermonuclear weapons testing in the 1960s, which generated large amounts of radiocarbon, which were absorbed by species in ocean ecosystems. The study authors concluded that sharks with higher radiocarbon levels in the nucleus of their eye tissue were born after the so-called “bomb pulse” and were younger than 50 years old, whereas sharks with lower radiocarbon levels were born before the “bomb pulse” and were at least 50 years old or older.
The scientists then estimated the age of the older sharks based on their size and previous data on Greenland shark size at birth and fish growth rates.
The sharks were at least 272 years old, and may be as much as 512 years old (!) according to the results of the investigation, which had a 95% probability rate, with 390 years as the most likely average life span, according to Nielsen.
However, why do Greenland sharks live for such a long time?
Their extended lifespan is due to their sluggish metabolism and the chilly waters in which they live. They travel so slowly in the icy waters of the Arctic and the North Atlantic that they’ve acquired the moniker “sleeper sharks.” Sharks have been found with seal pieces in their guts, but because sharks move so slowly, researchers believe the seals were either sleeping or already dead when they were eaten.
The farther you travel, the slower you move.