A little-understood species of shark is the longest living of all vertebrate animals, new research has revealed.

The Greenland shark, among the largest to hunt in the ocean, can live to be at least 272 years, with one female studied thought to be about 400 years old.

The findings put the shark well ahead of other long-living vertebrate animals - the next oldest is the bowhead whale, which can live to be 211.

The startling findings come from research led by marine biologists at the University of Copenhagen who used carbon dating techniques on tissue from the shark's eyes.

Julius Nielsen, the lead author of a report published in the journal Science, said:

Carbon-14 dating of eye lenses has been used previously to discover the age of whales, but this is the first time it has been used to estimate the life expectancy of fish.

The Greenland sharks often end up trapped in the nets of North Atlantic fishermen, and it is hoped the study will add to conservation efforts.

"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," said Nielsen.

"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."