Meet the Shark That’s Twice as Old as America

Meet the longest-lived animal with a backbone. Scientists estimate that Greenland sharks live for around 250 years, but some may live as long as 500 years. These cold-water sharks not only eat sea mammals and fish, but have also been known to consume other random animals that may have fallen through the ice by accident. Remarkably, Greenland sharks have even been found with the remains of polar bears in their stomachs.

Where Do Greenland Sharks Live?

There has never been a reported attack of Greenland sharks on humans. This has less to do with the behavior of the Greenland shark and more to do with where it lives. Greenland sharks swim in frigid waters where humans can’t survive.

Greenland sharks live in the North Atlantic and Arctic Oceans, where the water temperature ranges from 29 to 50 degrees Fahrenheit. While they can be found closer to the surface, they are also known to swim to depths of over 7,000 feet.

Though they are mainly found in the cold northern waters, Greenland sharks have rarely been spotted in the South Atlantic Ocean, but only at thousands of feet below the surface.

What is the Anatomy and Appearance of the Greenland Shark?

Greenland sharks (Somniosus microcephalus) are a type of “sleeper shark” in the Family Somniosidae. Sleeper sharks are known to be sluggish and slow. Greenland sharks are massive, weighing up to 2,000 pounds and growing up to 24 feet long. This is comparable to the size of a great white shark. They have small heads, eyes, and gill slits with a large torpedo-shaped body. Their color is a medium grey to brown, and they have small blotches of lighter colors along their body.

If you’d like to get a better look at a Greenland shark swimming in its environment, check out this YouTube video from Animalogic. The video shows some amazing close-up footage of a Greenland shark swimming through the depths, along with interesting facts about its behavior.

Greenland Shark’s Behavior and Diet

They are the apex predators in their habitat and will eat a variety of fish, as well as squid, seals, and even smaller invertebrates such as mollusks. In addition to fresh food, they will scavenge rotting meat. Astoundingly, Greenland sharks have been found with the remains of reindeer, polar bears, moose, and horses in their stomachs. Scientists speculate that these large mammals probably fell through a thin sheet of ice into the icy depths where the opportunistic sharks were waiting.

Although they are fearsome predators, Greenland sharks are slow-moving with slow metabolisms. The shark travels at the insanely slow speed of .75 miles per hour. When sprinting, it can reach speeds of 1.6 miles per hour.

Greenland sharks are often blind due to parasites that attack their eyes. But this doesn’t stop them from catching their prey. Because they don’t have the speed to chase their prey, they rely on stealth. Greenland sharks sneak up on sleeping animals. They then open their mouth (or buccal cavity) and suction up the animals, often swallowing them whole.

These large sleeper sharks don’t need to feed often because their calorie needs are very low. They conserve a lot of energy by moving slowly.

What Is the Oldest Confirmed Greenland Shark?

Scientists believe that Greenland sharks may live for 500 years or longer. Greenland sharks have such long lifespans that they do not reach sexual maturity until they are 150 years old. The eggs are fertilized by male sharks inside the mother’s body, where they remain until they are born. The gestation period can last up to 18 years. With such a long reproductive cycle, it’s not surprising that Greenland sharks are the oldest known vertebrates on the planet.

Scientists studied the ages of 28 female Greenland sharks that were caught up in by-catch by studying the radiocarbon dating of proteins in their eyes. The oldest shark they found was nearly 400 years old, but the scientists say her actual age may have ranged from 272 years to 512 years.

Greenland Sharks are ‘Near Threatened’

Because Greenland sharks live in such cold, deep waters, not much research has been done on them. Scientists don’t know the exact size of the population of Greenland sharks, but they are considered “Vulnerable” by the World Conservation Union (IUCN).

Sadly, part of what makes them so unique (their slow metabolism, growth rate, and maturity) also puts them in danger of overfishing. It’s harder for a slow-reproducing species to recover from a decline. They also get caught up in fishermen’s nets as bycatch. Because they move slowly, they can’t escape the nets. And their scavenger nature makes them attracted to the bait and waste around fishing boats.