How Long Do Greenland Sharks Live?

Scientists think Greenland sharks live for a very long time. For many years, they had no good way to measure a shark's age. Other sharks show age with marks on hard body parts, like the rings of a tree. Greenland sharks do not have these hard parts. Scientists only knew that the animals grow less than one centimeter each year. The sharks can also grow longer than six meters.

Now scientists can test special proteins in a shark's eye. These proteins form before the shark is born and stay the same for life. In one study, fishers caught some sharks by accident. The biggest shark was a female five meters long. Scientists said she was between 272 and 512 years old. The test gives a range, not an exact age. Even 272 years would make this shark the longest-living animal with a backbone.

One idea is that the shark's body uses energy very slowly. This helps the shark live in cold, deep water. It is the only shark that can live all year in the freezing Arctic Ocean. The slow use of energy may explain its slow growth, slow aging, and slow swimming. Scientists think it does not have babies until it is more than 100 years old. So taking adult sharks from the sea can hurt the group for many years. People once hunted Greenland sharks for oil in their livers. Today most are caught by accident. Catching fewer of them is important to protect this unusual animal.

What fact about Greenland sharks surprises you the most?