The Greenland shark (Somniosus microcephalus) is one of those creatures that makes you question whether nature has any sense of urgency at all. This deep-sea predator, lurking in the cold, dark waters of the North Atlantic and Arctic Oceans, can live for roughly 400 years, and possibly longer. That makes it the longest-lived vertebrate known to science. A fish that may have been alive when Shakespeare was writing plays is still out there, swimming around in the freezing dark, doing absolutely nothing in a hurry.
How long do sharks live?
Most species live somewhere between 20 and 70 years. The Greenland shark is the great exception. Radiocarbon dating put the largest one ever studied at about 392 years old, give or take 120, which makes it the longest-lived vertebrate known to science.
It’s wild to think about such a large animal outliving entire civilizations. And it’s very difficult to see one in person, which makes good photography hard to come by. Most of what we know comes from rare deep-sea encounters and the occasional unlucky bycatch specimen.
A Slow and Steady Life
If there were a prize for the world’s most unhurried animal, the Greenland shark would win it. Eventually. These sharks swim at roughly 1.12 kilometers per hour (about 0.7 mph), which is less a swim and more a gentle drift with intent. For comparison, the average human walks at about 5 km/h. You could outpace a Greenland shark in a brisk stroll. You could probably outpace one while half asleep.
This glacial pace matches every other aspect of their biology. They grow less than one centimeter per year and can reach lengths of over 6 meters (about 20 feet). That means a 5-meter Greenland shark has been quietly growing since roughly the time of the French Revolution. They live at depths between 200 and 600 meters, though some have been recorded at a staggering 2,200 meters below the surface, far deeper than sunlight can reach.
Their body temperature hovers near the freezing point of water. Everything about them is slow: their heartbeat, their digestion, their growth. In a world obsessed with speed and optimization, the Greenland shark is the ultimate counterargument. It just exists. Patiently. For centuries.
The Secret to Their Extraordinary Longevity
So how does a shark live for half a millennium? The answer, as far as scientists can tell, comes down to cold water and an absurdly slow metabolism.
The near-freezing temperatures of the Arctic and deep North Atlantic slow down virtually every biological process in the shark’s body. Cell damage accumulates more slowly. Growth happens at a crawl. Even reproduction takes its time: female Greenland sharks are believed not to reach sexual maturity until they’re roughly 150 years old. Think about that. This shark spends longer being a teenager than most species spend being alive.
The breakthrough in understanding their age came from a clever bit of science. In 2016, a team of researchers led by Julius Nielsen used radiocarbon dating on the eye lenses of 28 Greenland sharks. The crystalline proteins in the eye lens form before birth and don’t change afterward, making them a kind of biological time capsule. By measuring the carbon-14 in these proteins (some of which originated from Cold War-era nuclear bomb testing), the researchers determined that the largest shark in their study, just over five meters long, was about 392 years old, give or take 120 years.
That would place its birth somewhere between the late 1500s and the early 1700s, and quite possibly around the 1620s, just as the Pilgrims were settling in at Plymouth. Before Newton. Before the steam engine. This one fish!
How Long Do Other Sharks Live?
To see just how strange the Greenland shark is, it helps to line it up against its relatives. These are the best current estimates from age studies:
- Greenland shark: at least 272 years, with the largest estimated at about 392
- Great white shark: at least 73 years, the oldest male in a 2014 Woods Hole study
- Whale shark: at least 50 years confirmed, and possibly around 100
- Spiny dogfish: usually up to about 30 years, with records near 40
- Bull shark: more than 25 years
- Tiger shark: aged to about 20 to 22 years, with predicted maximums near 29
Even the famous great white, a giant among sharks, would be a teenager next to a Greenland shark that has only just reached maturity.
A Mysterious Predator of the Deep
Despite being one of the largest predatory sharks in the ocean, the Greenland shark remains stubbornly mysterious. It feeds on a wide variety of prey: fish, seals, squid, and carrion. Stomach contents have revealed some surprising finds over the years, including the remains of polar bears, reindeer, and horses. Whether they actively hunt large mammals or scavenge them after death remains an open question. Given their swimming speed, the scavenging theory seems more plausible, but some scientists believe they may ambush sleeping seals.
One of the stranger aspects of the Greenland shark is its relationship with a particular parasite. Many Greenland sharks have a small, bioluminescent copepod called Ommatokoita elongata attached to their eyes. This parasite feeds on the corneal tissue, often causing significant damage to the shark’s vision. Some researchers have speculated (though this remains debated) that the glowing parasites may actually attract prey toward the near-blind shark, turning a handicap into an accidental lure. Whether or not that’s true, the image is something: a half-blind, 500-year-old shark with glowing parasites dangling from its eyes, drifting through absolute darkness.
Their flesh is also toxic when fresh, loaded with trimethylamine N-oxide (TMAO) and urea, chemicals that act as a natural antifreeze. In Iceland, there’s a traditional dish called hákarl, which is Greenland shark meat that has been buried underground and fermented for several months to neutralize the toxins. It is, by most accounts, one of the more challenging culinary experiences on Earth. Anthony Bourdain once called it the single worst thing he’d ever eaten. The smell has been compared to very strong ammonia. It’s an acquired taste, and most people never acquire it.
The Unique, Almost Cartoonish Face
If you’ve ever seen a Greenland shark up close (in photos, at least, since seeing one in person requires serious deep-sea credentials), you’ll notice something about its face. It looks almost comically gentle. The small eyes, the rounded snout, the slightly upturned mouth give it a perpetually bemused expression, like it’s mildly surprised to find itself still alive after all these centuries. It’s the face of an animal that has seen it all and is no longer impressed.
Compared to the dramatic, angular menace of a great white shark, the Greenland shark looks like it was designed by someone going for “approachable.” This is a shark you could imagine at a library, not a thriller movie. And yet it is a legitimate apex predator in its environment, capable of taking down seals and large fish. Appearances, as always, are deceiving.
Conservation and the Long View
The extraordinary lifespan of the Greenland shark creates a unique conservation challenge. An animal that takes 150 years to reach reproductive maturity cannot bounce back quickly from population declines. Every individual lost to bycatch or commercial fishing represents centuries of growth. And bycatch is a real threat: Greenland sharks are frequently caught unintentionally in deep-sea trawl nets and longline fisheries targeting other species.
The International Union for Conservation of Nature (IUCN) currently lists the Greenland shark as “Vulnerable,” but our understanding of their population size is limited. They’re difficult to study, difficult to count, and difficult to track. What we do know is that removing long-lived animals from an ecosystem has ripple effects that can take generations to manifest.
There is also growing scientific interest in what the Greenland shark can teach us about aging itself. An animal that can live for 500 years without developing cancer at notably higher rates than short-lived species may hold clues to the biological mechanisms of longevity. Researchers are studying their DNA, looking for genetic adaptations that might explain their resistance to age-related diseases. It’s the kind of research that probably won’t yield answers quickly. Which, given the subject, feels appropriate.
Since then: In 2026, a team at the University of Tokyo published the Greenland shark genome in PNAS. It is roughly twice the size of our own and shows expanded DNA repair and immune genes, the kind of toolkit that might help a body keep going for centuries.
Still Out There
The Greenland shark shows what’s possible when evolution chooses endurance over speed. While other predators evolved to be fast, flashy, and aggressive, the Greenland shark went the other direction entirely. It chose the cold. It chose the dark. It chose to move so slowly that prey might not even notice it coming. And somehow, against all apparent logic, it became one of the most successful survival stories in the animal kingdom.
There is something quietly humbling about knowing that right now, in the deep waters of the Arctic, there may be sharks that were already alive when the Pilgrims landed at Plymouth Rock. Before Newton’s apple. Before electricity. They’ve been down there, moving at less than a mile per hour, through every war, every revolution, every technological leap humanity has ever made. Completely unbothered.
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Frequently Asked Questions About the Greenland Shark
How long can a Greenland shark live?
The Greenland shark is the longest-lived vertebrate known to science. Radiocarbon dating of eye lens proteins shows they live at least 272 years, and the largest shark studied was estimated at about 392 years, give or take 120. A 2016 study published in the journal Science established these age estimates using carbon-14 analysis.
Why do Greenland sharks live so long?
Their extraordinary longevity is attributed to their extremely slow metabolism, driven by the near-freezing water temperatures of the Arctic and deep North Atlantic. Cold temperatures slow cellular processes, reduce oxidative damage, and decelerate aging. They grow less than one centimeter per year and do not reach sexual maturity until approximately 150 years of age.
Are Greenland sharks dangerous to humans?
Greenland sharks are not considered dangerous to humans. They live in deep, cold water far from typical swimming or diving areas, and they move extremely slowly (about 0.7 mph). There are no confirmed unprovoked attacks on humans. Their temperament is docile, and encounters with people are exceedingly rare.
What is hákarl, and is Greenland shark meat toxic?
Fresh Greenland shark meat is toxic due to high concentrations of trimethylamine N-oxide (TMAO) and urea, which act as natural antifreeze in the shark’s body. Hákarl is a traditional Icelandic dish made by burying and fermenting Greenland shark meat for several months to break down these toxins. The resulting product has an extremely strong ammonia-like smell and is considered an acquired taste.
Are Greenland sharks endangered?
The Greenland shark is currently classified as “Vulnerable” by the International Union for Conservation of Nature (IUCN). Their primary threat is bycatch in commercial deep-sea fisheries. Because they do not reach reproductive maturity until around 150 years old, population recovery from declines is exceptionally slow, making conservation efforts particularly important.
