Long in the tooth: the Greenland shark may live four centuries

Danish researchers say that the Greenland shark, which are relatively abundant in the North Atlantic and the Arctic, should be considered the oldest vertebrate animal in the world. Julius Nielsen / ReShow more

WASHINGTON // The Greenland shark, a big and slow-moving, deep-ocean predator that prowls the Arctic and North Atlantic, can claim the distinction of being the planet’s longest-living vertebrate, with a lifespan perhaps reaching about 400 years.

Its slow growth rate, about one centimetre per year, tipped off scientists that it lived a very long time, and research calculated the Greenland shark’s lifespan for the first time.

Marine biologist Julius Nielsen said radiocarbon dating that analysed the shark’s lens found that the oldest of 28 sharks studied was likely to be aged about 392 years old, with 95 per cent certainty of a range in age between 272 and 512 years.

Females did not reach sexual maturation until they were at least 134 years old.

The Greenland shark, up to about 5.5 metres long, is among the largest carnivorous sharks.

Mr Nielsen, a University of Copenhagen doctoral student who led the study published in the journal Science, said the findings should bring this shark much-deserved respect.

“This species is completely overlooked, and only a few scientists in the world are working with this species,” he said. “Our findings show that even though the uncertainty is great that they should be considered the oldest vertebrate animal in the world.”

Mr Nielsen said the vertebrate with the longest-known lifespan until now was the bowhead whale, topping 200 years.

Greenland sharks have a plump, elongated body, round nose, relatively small dorsal fin, sandpaper-like skin and grey or blackish-brown colouration.

They are slow swimmers and are nearly blind, but are capable hunters, eating fish, marine mammals and carrion.

They are known to be relatively abundant in the North Atlantic and Arctic, from eastern Canada to western Russia.

They occasionally are spotted by deep-sea robotic submarines at latitudes further south, such as in the Gulf of Mexico. They have been observed in depths down to 2.2 kilometres.

“They may widely inhabit the deep sea, potentially living anywhere water temperatures are below about 5° Celsius,” said Australian Institute of Marine Science marine biologist Aaron MacNeil, who was not involved in the study.

Mr MacNeil said the study did an admirable job of tackling a difficult matter but questioned an element of the dating analysis and said the estimate of a roughly 392-year-old shark “seems high to me”.

* Reuters