Greenland shark

The Greenland shark, also known as the gurry shark or grey shark, and by its Kalaallisut name, eqalussuaq, is a fascinating creature found in the North Atlantic and Arctic Oceans. These sharks rank among the largest in the world and can live for an astonishing 300 to 500 years, making them the longest-living vertebrates known.

Reaching up to 7.3 meters (24 feet) in length and weighing over 1,400 kilograms (3,086 pounds), Greenland sharks are true giants of the deep. They have a distinctive set of teeth: thin, pointed ones on the upper jaw and broad, square ones on the lower jaw. These apex predators have a varied diet, feeding on fish, seals, and other marine creatures. They are also scavengers, often found around fishing boats where they feast on decomposing meat.

Due to the frigid waters they inhabit, Greenland sharks have a slow metabolism and swim at leisurely speeds. Instead of migrating over long distances, they move vertically within the water column, adjusting to depth and temperature variations. They have been found as deep as 2,200 meters (7,218 feet). Their bodies are adapted to these cold environments with high levels of urea and trimethylamine N-oxide in their tissues.

Interestingly, the flesh of the Greenland shark is toxic due to high levels of trimethylamine N-oxide. However, in Iceland, it is prepared as a delicacy called kæstur hákarl through methods such as boiling, drying, or fermenting to make it safe to eat.

Greenland sharks are also steeped in legend. Inuit folklore tells of Skalugsuak, the first Greenland shark, and its connection to Sedna, the goddess of the sea. These tales add to the mystique of this remarkable shark, whose unique characteristics and incredible longevity continue to captivate researchers and storytellers alike.