Greenland sharks eat any meat they find, from seals to whale carrion.
24 feet (7.3 m)
7,200 feet (2,200 m)
Arctic waters at temperatures between -2 and 7 degrees Celsius.
The Greenland shark is perhaps the most peculiar species of shark, found in the icy Arctic waters often at depths of 2,000 metres, down in the midnight zone of the ocean. Living at such depths has led to Greenland sharks experiencing something known as ‘deep sea gigantism’, which is the tendency for deep-sea dwelling species to be larger than their shallower-water relatives.
With some growing to 6 metres long, and weighing 2,000 pounds, they are certainly among the largest shark species in the world. But despite their size, there are no cases of attacks on humans. They are primarily scavengers. Their close relatives, Pacific Sleeper Sharks, have strangely enough have been known to eat another ocean leviathan. Beaks of the mighty colossal squid have been found in their stomachs; invertebrates even more elusive than this deep-sea shark.
The Greenland shark is truly a living fossil, with some individuals thought to be 400 years old, and possibly more. The transparent tissue of their eye lens is metabolically inactive, and new layers are added as the sharks grows older, much like the rings of a tree. When scientists experimented on the lens tissue of 28 female Greenland sharks from the north Atlantic, using radiocarbon dating on the innermost layer of the lens, they estimated the two biggest sharks to be around 335 to 392 years old.
The strange organism found in the eyes of almost all captured Greenland sharks is a crustacean parasite that feeds on the corneal tissue, scarring the eyes. The sharks become nearly blind as a result, but down in the depths of the midnight zone, eyesight is not a necessity.
With enlarged eyes, bioluminescent photophores, and often growing to enormous sizes, fish of the deep are oddly fascinating.
The deeper you dive beneath the waves, the larger the invertebrates become. This demonstrates the phenomenon of deep sea gigantism.
Many mammals, from seals to the mighty cetaceans of the open seas, frequent the depths of the ocean, diving down in search of prey.
Though they may not dominate the seas as they once did, reptiles still play a vital part in the marine ecosystem, from turtles to sea snakes.
Read our in-depth write-ups about the environment, ecosystems, adaptations, and discoveries related to the deep sea. Individual animal profiles can be found by clicking 'fact files' in the menu above.
Ah, the ocean. Rolling blue waves, picturesque seascapes, and a bottomless abyss of sheer darkness. With only 5% of the ocean having been discovered, there is much to explore.
Environmental degradation has reached even the isolated depths of the ocean, a realm we know little about, yet have caused much damage to with our destructive nature.
We are only now beginning to understand the importance of deep sea ecosystems, from hydrothermal vents that mitigate climate change, to whale-falls that provide a large carbon sink.