Greenland sharks: The longest living vertebrate?

Imagine being alive during the American Revolution. According to Danish researchers at the University of Copenhagen, a shark was old enough to have lived before the United States was ever a thought in George Washington’s head, and even before Washington’s parents were born. That shark was a female Greenland shark (Somniosus microcephalus).

Greenland sharks are already known for living over 200 years, but this shark has been estimated to have lived up to 400 years of age! This makes the oldest human alive look like an infant.

“We definitely expected the sharks to be old, but we didn’t expect that it would be the longest-living vertebrate animal,” says Julius Nielsen of the University of Copenhagen, Denmark, according to New Scientist.

Picture of a Greenland Shark. Credit: npr.org

Living in the cold waters of the Arctic and in the North Atlantic, Greenland sharks have a slow growth rate, only growing a few centimeters per year. Despite this, they can grow up to over 500 cm (around 16 feet long). The older a shark is, the more attractive they are, as female Greenland sharks aren’t even able to reproduce until they are 150 years of age! The main cause for their long lifespan is unknown, but scientists believe it has to do with their cold habitat, which lowers their metabolism, causing them to age at a slower rate.

Their diet consists of fish, smaller sharks, or eels. It’s surprising these sharks are able to eat such a variety of fish without their dentures falling out.

To determine how long a Greenland shark has lived, the researchers examined 28 deceased sharks using a method known as radiocarbon dating. This method examines the sharks’ organic material using the properties of radiocarbon. Out of the 28 sharks examined, the oldest was a female Greenland shark that was determined to be around 400 years of age at the time of her death. This beat the previous record holder for oldest vertebrate, which belonged to a 211-year-old bowhead whale.

It’s surprising that these sharks have lived through many significant parts of history. They have outlived billions of people and will even outlive us, including our grand kids!