narwhal(redirected from Monodon)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
narwhal(när`wəl), a small arctic whalewhale,
aquatic mammal of the order Cetacea, found in all oceans of the world. Members of this order vary greatly in size and include the largest animals that have ever lived. Cetaceans never leave the water, even to give birth.
..... Click the link for more information. , 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 belugabeluga
or white whale,
small, toothed northern whale, Delphinapterus leucas. The beluga may reach a length of 19 ft (5.8 m) and a weight of 4,400 lb (2,000 kg).
..... Click the link for more information. , 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 ChordataChordata
, phylum of animals having a notochord, or dorsal stiffening rod, as the chief internal skeletal support at some stage of their development. Most chordates are vertebrates (animals with backbones), but the phylum also includes some small marine invertebrate animals.
..... Click the link for more information. , subphylum Vertebrata, class Mammalia, order Cetacea, family Monodontidae.
See studies by F. Bruemmer (1993), J. Rosing (1999), and T. McLeish (2013).
(Monodon monoceros), a mammal of the subfamily Delphinapterinae of the family Delphinidae. The female is up to 5 m long, and the male up to 6 m long. Males may weigh as much as one ton. The newborn calf is about 1.5 m long. The narwhal has a rounded head and lacks a dorsal fin. The adults are light yellow with black spots; the newborns are black. The narwhal has only two upper teeth. The left tooth develops into a twisted tusk up to 3 m in length, the right tooth usually remains undeveloped. The narwhal is a rare species, found in arctic waters, primarily around Greenland and the northern part of the Canadian archipelago. Narwhals live among the ice and feed on cephalopods and fish.