Overview — The largest member of the dogfish family, the Greenland shark can grow to over 20 feet in length. This shark prefers cold-water temperatures and will usually only ascend from the depths if the surface drops to around 33 degrees Fahrenheit.
Also called the "sleeper shark," this species is often inactive and indeed appears to be sleeping. As its name indicates, the Greenland shark is found around Greenland, but it also exists in other parts of the North Atlantic, such as near Iceland.
Life may seem to be lonely in the ocean depths, but this shark often is found with a "best friend forever," a parasitic copepod that lives on the shark's eye and feasts on its corneal tissue. While the shark does suffer some damage, the relationship affords benefits. The parasite is bioluminescent. Its glow helps the shark to attract prey, similar to how a colorful fishing lure may attract fish.
Feeding Habits — Fish constitute the largest portion of the Greenland shark's diet. They may also consume large sea mammals, such as seals. If something looks like food, however, this shark will gobble it down. Some Greenland shark stomachs have contained pieces of horses and polar bears. One shark even consumed an entire reindeer, antlers and all.
Cool Fact — The size of the largest known Greenland sharks remains in dispute, with some scientists believing this species could exceed many great white sharks in length.
Common Max Depth — 6,561 feet