Deep beneath the icy waters of the Arctic lives one of nature’s most astonishing survivors: the Greenland shark. This elusive species can live for more than 300 years, making it the longest-living vertebrate known to science.
Moving slowly through frigid seas, it grows just a few centimetres each year and reaches maturity only after more than a century. Despite its size and age, the Greenland shark remains mysterious, spending most of its life in near darkness where few humans ever venture.
This article is for general knowledge only and is based on information from reputable marine biology and research sources.
1. The Longest-Living Vertebrate
In 2016, researchers used radiocarbon dating on the shark’s eye tissue and found individuals estimated to be 272 to 512 years old. This makes the Greenland shark the oldest known living vertebrate, far surpassing turtles, whales, and other long-lived animals.
Consider that some sharks alive today were born before the Industrial Revolution. Their remarkable longevity offers scientists valuable insights into aging and survival in extreme environments.
2. An Unusual Diet
Greenland sharks are opportunistic feeders. They eat fish, seals, squid, and carrion, but scientists have even found remains of reindeer and polar bears in their stomachs, likely scavenged rather than hunted.
Finding land mammals inside a deep-sea shark surprises many people. These discoveries suggest the sharks feast on carcasses that sink from the surface, turning them into efficient ocean cleanup crews in Arctic ecosystems.
3. Toxic Flesh
Their flesh contains trimethylamine oxide, which makes it toxic if eaten raw, causing effects similar to intoxication in humans and animals. In Greenland and Iceland, people prepare the meat through a special fermentation process to make it safe to consume, known as hákarl.
This traditional dish has a strong ammonia smell and acquired taste. The toxin helps the shark regulate its body chemistry in salty ocean water.
4. Parasites On Their Eyes
Many Greenland sharks carry parasites called copepods that latch onto their eyes, sometimes leaving them nearly blind. However, blindness doesn’t stop them from thriving, as they rely more on smell than sight.
Scientists believe the parasites may even glow slightly, possibly attracting prey in the dark depths. Whether this benefits the shark remains unclear, but these ancient fish clearly manage well without perfect vision.
5. Conservation Concerns
Although not widely hunted today, Greenland sharks are considered Vulnerable by the IUCN. Their extremely slow reproduction makes them particularly at risk from bycatch and climate change.
A single shark may take 150 years just to reach breeding age. If populations decline, recovery could take centuries. Protecting these ancient survivors requires careful management of fishing practices and awareness of their fragile life cycle in warming oceans.
