narwhal

narwhal när´wəl [key], a small arctic whale , Monodon monoceros. The males of the species, and an occasional female, bear a single, tightly spiraled tusk that measures up to 9 ft (2.7 m) in length. The tusk is an overgrown upper canine tooth, generally the one on the left, that emerges through the upper lip. Very rarely do both canines grow out in this manner; the narwhal is otherwise toothless. Although the functions of the tusk are unclear, it lacks enamel and is nerve-rich, and can sense changes in the environment. Males also appear to use it in sparing with other males.

The narwhal is short-headed and virtually snoutless. When mature, it is mottled gray in color. Like its close relative the beluga , it lacks a dorsal fin, but it does have a long, low dorsal hump. The narwhal may reach a length of 20 ft (6.1 m), excluding the tusk. It is found in the Arctic and N Atlantic oceans, occasionally as far south as Britain; narwhals usually travel in groups of 15 to 20 animals. The diet of narwhals consists chiefly of cuttlefish and cod. Mating occurs in the summer, and after a gestation of 14 months the female gives birth to a single blue-gray calf measuring up to 5 ft (1.5 m). The calves are weaned at six months. Formerly killed for its tusk, which was believed to have magical properties (and was sold for centuries as a unicorn horn), the narwhal is now hunted by native peoples for food and for the tusk.

The narwhal is classified in the phylum Chordata , subphylum Vertebrata, class Mammalia, order Cetacea, family Monodontidae.

See studies by F. Bruemmer (1993), J. Rosing (1999), and T. McLeish (2013).

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