Greenland shark (Somniosus microcephalus) Amongst the world’s largest sharks, the Greenland shark is an elusive species of dogfish that inhabits the icy waters of the Arctic and the northern Atlantic. Also known as the large sleeper shark for its sluggish movements, the body is heavy-set, the spineless dorsal fins are greatly reduced, and the snout is short and rounded. For a shark of its size, the gill slits are also notably small, and located low on the side of the head. Although this shark’s colouration ranges from brown to black to grey, the skin is often marked with dark lines or white spots, whilst the entire body is covered in closely packed, teeth-like denticles.