The Greenland shark holds the title of the longest-living vertebrate on Earth, with scientists estimating the age of one female shark to be approximately 400 years. This discovery was made through radiocarbon dating of eye proteins from 28 Greenland sharks, surpassing the previous record held by a bowhead whale, which was estimated to live up to 211 years.
Julius Nielsen, a marine biologist from the University of Copenhagen and the lead researcher on the study, remarked, “We had our expectations that we were dealing with an unusual animal, but I think everyone doing this research was very surprised to learn the sharks were as old as they were.”
Greenland sharks, often referred to as “sleeper sharks” due to their slow movements, inhabit the frigid waters of the Arctic and North Atlantic. These enormous creatures, capable of growing up to 5 meters in length, have an extremely slow growth rate of just 1 centimeter per year. They reach sexual maturity only after attaining a length of about 4 meters, which corresponds to an age of roughly 150 years.
The study leveraged radiocarbon levels in the sharks’ eye tissue, a technique made feasible by the fallout from atmospheric nuclear testing in the 1960s. Sharks with higher radiocarbon levels in their tissues were identified as less than 50 years old, while those with lower levels were estimated to be significantly older. For the oldest sharks, researchers combined data on their size, growth rates, and known birth size to estimate their age, concluding they were at least 272 years old, possibly as old as 512 years, with the most likely age being 390 years.
The exceptional longevity of Greenland sharks is attributed to their extremely slow metabolism and their cold-water habitat. Despite their sluggish nature, they have been found with seal remains in their stomachs, leading experts to believe they likely consume seals that are either asleep or deceased.
This research provides remarkable insight into the biology of one of Earth’s most mysterious and enduring creatures.
