The Greenland shark is the world's longest living vertebrate and one of the longest living animals ever.
A Greenland shark swimming in the cold depths of the ocean.
Icelanders call it “Skalugsuak,” after an old Inuit legend that claims that it lives in the urine pot of Sedna, the goddess of the sea, and that its flesh can destroy human skin. But most people know it as the Greenland shark.
For years, scientists believed that Greenland sharks, like most sharks, had a lifespan of only about 100 years. However, recently scientists have discovered that their lifespans could be much greater than anyone ever thought: up to 500 years.
This is the story of longest living vertebrate.
The Whacky Characteristics Of The Greenland Shark
A Greenland shark and diver swim among plumose anemones in the St. Lawrence River in Canada
The Arctic Greenland shark’s native nickname actually inspires a fitting image for Skalugsuak, whose flesh, coincidentally, smells like urine, and if consumed raw can be toxic to humans.
Not quite as majestic, fearsome or awe-inspiring as some other large sea creatures, the Greenland shark is actually relatively ugly. Its long, thick, gray body is brown, and its small head consists of a short, rounded snout and tiny eyes, often plagued by worm-like parasites that trail from its head.
The shark survives on a diet of mostly halibut, and other large fish – though the remains of polar bears have been found in their stomachs. The Icelandic people consider the flesh of the Greenland shark to be a delicacy and put it through a months-long fermenting process in order to render it safe to eat. Without it, the effects of the meat cause symptoms similar to severe drunkenness.
One of the most recognizable features of the Greenland shark is its small, bright eyes. Its eyes are home to a stomach-turning parasite called Ommatokoita elongata.
Avalon.red/Alamy Stock PhotoGreenland shark with an eye parasite called Ommatokoita elongata.
These parasites render the shark partially blind, but thankfully the light-devoid environment in which the Greenland shark spends the majority of its life doesn’t call for much eyesight.
Instead, the shark uses its other senses and also practices patience to catch prey. They typically feed on other small sharks, eels, bony fish, and marine mammals.
Greenland sharks are also called sleeper sharks in regard to their slow pace. According to the National Oceanic and Atmospheric Administration (NOAA), the sharks move at a pace of 1.8 miles per hour. Despite their snail-like pace, they’re considered an apex predator.
These slow-moving creatures often hunt anywhere from 700 to 2,200 meters under the freezing sea. They are the only shark that can live in these conditions in the Arctic year-round.
Immortal Sharks? The Greenland Shark Pushes Boundaries Of Longevity
Doug Perrine/Alamy Stock PhotoGreenland shark and a diver in the St. Lawrence River in Canada.
What makes the Greenland shark so fascinating, however, is not what is known about it, but what remains a mystery.
Despite rumors to the contrary, the oldest living Greenland sharks are probably not 500 years old.
But, it turns out, the number isn’t actually that far off, but figuring out the exact age of one of these deep-sea creatures is difficult.
According to Live Science, in sharks like Great Whites, scientists can use the hard vertebrae to figure out the shark’s age, counting them like tree rings. However, unlike most sharks, the Greenland shark is “soft” – its vertebrae don’t harden as much as others. So, scientists had to come up with a new method.
Julius Nielson/InstagramGreenland shark eye lenses.
Using the crystalline from the eye of a Greenland shark, scientists were able to perform carbon dating on 28 sharks. What they found shocked them. The Greenland shark had the longest known lifespan of any living vertebrae, and that, even considering a wide margin of error, it could live anywhere from 250 to 500 years.
The longest shark surveyed, and likely the oldest, was roughly 392 years old. This five-meter female shark had prowled the waters of the Arctic for over three centuries.
So what is it that allows these sharks to live so long? The secret lies in their icy, unforgiving habitat and perhaps, within their DNA.
An Unknown Life Under The Ice
WaterFrame/Alamy Stock PhotoA Greenland shark under the ice in northern Baffin Island.
Scientists historically attributed the Greenland shark’s advanced age to the cool temperatures that it lives in. They believed the cold environment was responsible for the creature’s remarkable age.
The temperature of the waters the Greenland sharks inhabit ranges from about 33 degrees Fahrenheit to 53 degrees Fahrenheit. The theory was these cold waters allowed for Greenland sharks to be the longest living vertebrae on land and in the sea.
Scientists thought that the nearly freezing water slowed their metabolism. When the metabolic process slows, everything slows – including aging. This slow metabolism impacts other behaviors as well, contributing to the creature’s slow speed.
Greenland sharks also take their time with physical development, growing very slowly. They grow one-third of an inch per year.
A Greenland shark doesn’t reach sexual maturity until they are over a century old. But their unique metabolism may not be the sole reason for their impressive age.
Scientists now believe the DNA of the Greenland shark may be the key to unlocking the secrets behind the Greenland shark’s age, while the freezing habitat may also contribute with their impressively sluggish metabolism.
Wikimedia CommonsThe Greenland shark can live up to 500 years old.
According to the New York Times, a team of scientists successfully mapped the genome of one of these sharks in 2024. In the sharks’ massive genome, researchers were surprised to find a number of harmful genes, leading them to discover the animal’s unique ability to duplicate genes in order to repair their DNA. This could be one explanation for their long life-span.
“These are animals that live longer than human beings, and they do this in the wild, without medicines or hospitals or health care,” João Pedro de Magalhães, a molecular biogerontologist at the University of Birmingham in England told the New York Times.
Researchers on the project believe that studying the way the Greenland shark’s DNA works may unlock more methods and information in treating conditions, such as cancer, in humans. But the future of this shark is uncertain, thanks to both fishing practices and climate change.
The Future Of The Greenland Shark
Wikimedia CommonsGreenland sharks were regularly fished throughout the early 20th century for liver oil.
According to the World Conservation Union (IUCN), the Greenland shark is “near threatened.”
According to the IUCN, nearly 3,500 Greenland sharks are accidentally caught every year in the Northwest Atlantic, Arctic Ocean and Barents Sea. Historically, fishermen have sought out the sharks for liver oil production.
While no longer being actively fished, they are still threatened by the industrialized fishing business, which since 1960 have accidentally caught Greenland sharks while catching large amounts of other types of fish in the North Atlantic Ocean.
It is hard to say how many Greenland sharks currently prowl the ocean, but researchers are confident that their species has been threatened by both human activity and climate change.
It’s estimated that ice loss and ocean temperature change due to climate change will greatly diminish the shark’s habitat. This would make it more difficult to hunt for food, as their prey may also see hits to their population in the diminishing Arctic ice.
This habitat loss could also increase the amount of fisheries present in Arctic waters as non-arctic fish move into the warming waters. These new fish could also increase the competition for food, adding yet another barrier to the Greenland shark’s survival.
Already, the population of the Greenland shark is estimated to have decreased by 30% to 49%. However, it’s difficult to truly gage what level of vulnerability the species is currently at.
Wikimedia CommonsThe Greenland shark lives only in the nearly freezing waters near the Arctic, a habitat that is threatened by climate change.
In the early 20th century, 32,000 Greenland sharks were caught each year to meet liver oil demand, and approximately 50,000 were caught in 1948. While this does mean at one point there were thousands of sharks, it’s difficult to tell how exactly these extensive fishing operations impacted the population of sharks who hadn’t yet reached maturity.
Because it takes over a century for Greenland sharks to reach the point where they can reproduce, disrupting their environments or removing them entirely could potentially have dramatic impacts on the entire population.
And speaking of climate change, researchers have also taken on the challenge of examining the tissues and bones of these sharks to measure the impact human behavior has had on the world’s oceans.
According to the Daily Mail, the sharks’ chemical composition may pinpoint exactly when pollutants began affecting them. Additionally, researchers can better understand the impacts of commercial fishing and other industries on the near-threatened species.
So while we marvel at the shark’s lifespan and funky-looking appearance, it is also important to remember just how much this incredible shark species has experienced and how much it can teach us.
Next, find out what killed the earth’s largest living shark. Then, read about the glow-in-the-dark shark that was found by scientists.
