Beastfile · Mammals

Narwhal

Monodon monoceros

Also known as Unicorn of the Sea

An Arctic whale whose tusk is really a tooth grown through its lip.

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Overview

The narwhal is a medium-sized whale of the high Arctic, and the tusk is the thing everyone knows about it. It is not a horn: it is a canine tooth, almost always the left one, that grows straight through the upper lip and can pass three meters. It spirals, always counter-clockwise. Mostly males carry one. The tusk is dense with nerve endings, which has led to the idea that it works as a sensor sampling the water, though narwhals have also been filmed using it to stun fish. They dive extremely deep beneath sea ice and spend their entire lives in Arctic water.

A narwhal breaking the surface in cold Arctic water, mottled grey skin visible

Origin

The Arctic waters of Canada, Greenland, Norway and Russia, following seasonal sea ice and wintering in deep, densely iced offshore areas.

Habitat

Arctic

Notable Traits

•The tusk is an elongated left canine tooth, not a horn
•It always spirals counter-clockwise
•Dives beyond 1,500 meters, among the deepest of any marine mammal
•Has no dorsal fin, which suits life under sea ice
•The tusk carries millions of nerve connections to its surface

Conservation

Least Concern overall, but narwhals are unusually exposed to a warming Arctic: they are tied to sea ice, they use a small number of wintering areas, and they are highly sensitive to underwater noise as shipping routes open.