A shark species found in Arctic seas may live for up to 400 years, making it the longest-lived vertebrate known.

Credit: Julius Nielsen

Julius Nielsen at the University of Copenhagen and his colleagues estimated the ages of 28 female Greenland sharks (Somniosus microcephalus; pictured), by radiocarbon dating the nuclei in the animals' eye lens. They concluded that the animals have a lifespan of at least 272 years, and that females don't reach sexual maturity until they are more than 100 years old.

The findings raise concerns about Greenland shark conservation, because a species that takes so long to begin reproducing could be at risk of being over-exploited by fisheries. The animal is also often inadvertently captured in nets cast for other species.

Science 353, 702–704 (2016)