Narwhal

Why in News?

Scientists recently discovered that a narwhal’s uniquely straight tusk remains strong because opposing twists in its inner and outer collagen fibril layers create internal tension that helps keep the tusk straight.

About Narwhal

The narwhal is a medium-sized toothed whale belonging to the family Monodontidae. The only other member of this family is the beluga whale.

Its scientific name is Monodon monoceros.

Habitat and Distribution

Narwhals are found mainly in the Arctic Ocean, particularly in the Atlantic sector, although they have also been recorded in the Pacific sector.

Their largest populations occur around Canada, Greenland, and eastern Russia.

They generally migrate seasonally. They move from under the ice during winter to inshore waters in spring and coastal waters during summer.

Physical Features

The Characteristic Tusk

The narwhal is best known for its long, spiraled tusk, which is actually a tooth. It is usually developed by males, although females may occasionally develop one.

The tusk can grow up to 3 metres in length and weigh more than 10 kilograms.

Recent observations suggest that males may use their tusks to hunt fish and to detect salt levels in the water through which they swim.

Body Structure

Narwhals have stout, torpedo-shaped bodies with a low dorsal ridge instead of a dorsal fin and a concave-shaped tail fin.

Like belugas, they possess short, paddle-shaped front flippers. However, they lack the extremely flexible neck and well-defined beak characteristic of belugas.

Adult narwhals are generally light grey with irregular black spots. These spots are more numerous on the back and fewer on the belly.

Behaviour and Feeding

Narwhals generally travel in groups of around 15–20 individuals, although much larger gatherings containing hundreds or even thousands of individuals have also been observed.

They are among the deepest-diving whales in the world and can hold their breath for approximately 25–30 minutes at a time.

Their diet consists mainly of fish, squid, and shrimp.

Narwhals use sound for communication as well as for navigation, hunting, and detecting their surroundings.

Why Are They Called the “Unicorns of the Sea”?

During medieval times, narwhals were hunted for their tusks, which were sold as supposed unicorn horns. This historical association gave the narwhal its popular nickname, the “unicorn of the sea.”

Conservation Status

The narwhal is classified as Least Concern (LC) under the IUCN Red List.