The narwhal ( Monodon monoceros ) is a small toothed whale inhabiting Arctic coastal regions and rivers. They lack a dorsal fin, have upturned flippers, and mottled gray bodies, darker on top. Adult males can weigh 1,600 kg and reach 3.5 to 5 meters in length, larger than females, which weigh about 1,000 kg. The males possess a long, straight tusk, that is actually an overgrown tooth with millions of nerve endings, which can grow to over 3 meters. They use it to hunt fish by stunning them and to detect salt levels in the water. Though once believed to be used in fights for mates, this is now thought to be less significant. Narwhals typically group in herds of 15 to 20. They feed on fish, squid, and shrimp, while killer whales, polar bears, and walruses prey on them. Inuit people hunt them for their ivory tusk and vitamin C-rich skin.

Where do narwhals live?

Narwhals are small toothed whales inhabiting Arctic coastal areas and rivers. They reside in the true Arctic Zone, where the upper water originates from the Arctic Ocean, specifically excluding areas with mixed Atlantic or Pacific waters. Narwhals usually group in pods of 15 to 20, but sometimes gather in herds of thousands. They use their sensitive tusks for hunting fish, shrimp, and squid by stunning them with taps. The tusk can also detect salt levels in the water, possibly to avoid frigid areas.

What makes the narwhal's appearance unique?

The narwhal's unique appearance is defined by a long, straight tusk that can grow to over 3 meters (9.8 feet) in length. This tusk projects forward from the upper jaw and features a left-handed spiral groove. Though it appears to be a horn, this feature is actually an overgrown tooth with sensory capabilities. Narwhals also lack a dorsal fin, and their flippers turn upward at the tips as they reach adulthood. Their bodies are a mottled gray, with the upper body darker than the lower. The origin of the word narwhal may be related to the Icelandic word for corpse, referencing the whale's pale color.

What is the purpose of the narwhal's tusk?

The narwhal tusk, found primarily in males, is actually a tooth that grows into a long, straight tusk projecting from the upper jaw. Recent studies suggest narwhals use their tusks to hunt fish, shrimp, and squid by tapping them to stun them for easier capture. The exterior of the tusk has many nerve endings that help narwhals detect salinity levels in Arctic waters, possibly to navigate away from frigid areas. While it was once believed that narwhals used their tusks for aggression, scientists now believe the tusk plays a more significant role in hunting and sensory functions. The tusk may also serve as a display feature to attract mates or establish social hierarchy within groups.

What do narwhals eat and how do they find food?

Narwhals eat fish, squid, and shrimp. They hunt by tapping their tusk on their prey to stun it before swallowing the creature whole. Narwhals also use their tusks to detect the level of salt in the Arctic waters, which may help them navigate away from frigid areas. Like other toothed whales, they use echolocation to find food, emitting a series of rapid clicks and using the echoes to discriminate objects in the water.

Why are narwhals sometimes called the 'unicorns of the sea'?

Narwhals are called the "unicorns of the sea" because the males possess a long, straight tusk that projects forward from above the mouth, resembling traditional depictions of the imaginary unicorn 's horn. During the Middle Ages, narwhals were hunted in the arctic waters of northern Europe, and their tusks were sold as unicorn horns to wealthy clients who likely had never seen a narwhal. Though once believed to be used in aggression, scientists now suggest that narwhals use their tusks to hunt fish and to detect the level of salt in the water.

narwhal

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Illustration of a narwhal (Monodon monoceros) with its long spiral tusk, shown alongside a faint scuba diver silhouette for scale. The narwhal's body is speckled gray and white, and a scale bar indicates its length of about 4 meters (13 feet).

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Related Topics:: What does a narwhal use its horn for?; tusk

On the Web:: World Animal Rescue Network - Narwhal (Nov. 08, 2026)

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narwhal

mammal

Also known as: Monodon monoceros, narwal, narwhale

Written and fact-checked by

Britannica Editors

Last updated

Nov. 8, 2026 •History

Top Questions

What is a narwhal?
The narwhal (Monodon monoceros) is a small toothed whale inhabiting Arctic coastal regions and rivers. They lack a dorsal fin, have upturned flippers, and mottled gray bodies, darker on top.

Adult males can weigh 1,600 kg and reach 3.5 to 5 meters in length, larger than females, which weigh about 1,000 kg. The males possess a long, straight tusk, that is actually an overgrown tooth with millions of nerve endings, which can grow to over 3 meters. They use it to hunt fish by stunning them and to detect salt levels in the water. Though once believed to be used in fights for mates, this is now thought to be less significant.

Narwhals typically group in herds of 15 to 20. They feed on fish, squid, and shrimp, while killer whales, polar bears, and walruses prey on them. Inuit people hunt them for their ivory tusk and vitamin C-rich skin.
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1. What Does a Narwhal Use Its Horn For?
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Where do narwhals live?
Narwhals are small toothed whales inhabiting Arctic coastal areas and rivers. They reside in the true Arctic Zone, where the upper water originates from the Arctic Ocean, specifically excluding areas with mixed Atlantic or Pacific waters.

Narwhals usually group in pods of 15 to 20, but sometimes gather in herds of thousands. They use their sensitive tusks for hunting fish, shrimp, and squid by stunning them with taps. The tusk can also detect salt levels in the water, possibly to avoid frigid areas.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What makes the narwhal's appearance unique?
The narwhal's unique appearance is defined by a long, straight tusk that can grow to over 3 meters (9.8 feet) in length. This tusk projects forward from the upper jaw and features a left-handed spiral groove.

Though it appears to be a horn, this feature is actually an overgrown tooth with sensory capabilities. Narwhals also lack a dorsal fin, and their flippers turn upward at the tips as they reach adulthood. Their bodies are a mottled gray, with the upper body darker than the lower. The origin of the word narwhal may be related to the Icelandic word for corpse, referencing the whale's pale color.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What is the purpose of the narwhal's tusk?
The narwhal tusk, found primarily in males, is actually a tooth that grows into a long, straight tusk projecting from the upper jaw.

Recent studies suggest narwhals use their tusks to hunt fish, shrimp, and squid by tapping them to stun them for easier capture. The exterior of the tusk has many nerve endings that help narwhals detect salinity levels in Arctic waters, possibly to navigate away from frigid areas. While it was once believed that narwhals used their tusks for aggression, scientists now believe the tusk plays a more significant role in hunting and sensory functions. The tusk may also serve as a display feature to attract mates or establish social hierarchy within groups.
2 Britannica Sources
1. What Does a Narwhal Use Its Horn For?
2. narwhal
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What do narwhals eat and how do they find food?
Narwhals eat fish, squid, and shrimp. They hunt by tapping their tusk on their prey to stun it before swallowing the creature whole.

Narwhals also use their tusks to detect the level of salt in the Arctic waters, which may help them navigate away from frigid areas. Like other toothed whales, they use echolocation to find food, emitting a series of rapid clicks and using the echoes to discriminate objects in the water.
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Why are narwhals sometimes called the 'unicorns of the sea'?
Narwhals are called the "unicorns of the sea" because the males possess a long, straight tusk that projects forward from above the mouth, resembling traditional depictions of the imaginary unicorn's horn. During the Middle Ages, narwhals were hunted in the arctic waters of northern Europe, and their tusks were sold as unicorn horns to wealthy clients who likely had never seen a narwhal. Though once believed to be used in aggression, scientists now suggest that narwhals use their tusks to hunt fish and to detect the level of salt in the water.
2 Britannica Sources
1. What Does a Narwhal Use Its Horn For?
2. narwhal
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

narwhal, (Monodon monoceros), a small toothed whale found along coasts and in rivers throughout the Arctic. Males possess a long straight tusk that projects forward from above the mouth.

Narwhals lack a dorsal fin, and in adults the flippers are turned upward at the tips. Their mottled gray bodies are darker above than below, and they usually attain a length of 3.5 to 5 metres (11.5 to 16.4 feet), males being larger than females. Adult males weigh about 1,600 kg (3,500 pounds); females weigh about 1,000 kg (about 2,200 pounds).

The narwhal has two teeth, both at the tip of the upper jaw, but usually only the left tooth develops. The resulting tusk grows to more than 3 metres (9.8 feet) and is grooved on the surface in a left-handed spiral. The undeveloped right tooth in males and usually both teeth in females remain vestigial. However, on rare occasions two tusks may develop in females as well as males. Although a variety of theories have been proposed for the specific function of the narwhal’s tusk, recent observations suggest that the males use their tusks to hunt fish and to detect the level of salt in the waters through which they swim. Previously authorities, including English naturalist Charles Darwin, believed that males use their tusks in aggression against one another in their competition for mates. The tusk was prized in medieval times as the horn of the fabled unicorn.

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Narwhals are usually found in groups of 15 to 20, but herds of several thousand have been seen. Newborn narwhal calves are about 1.6 metres (5.2 feet) long. Calves are weaned after a year or more; females reach sexual maturity at about six years and males at eight. Female narwhals experience menopause, and a significant portion of their life is spent in a post-reproductive phase. The longest-lived narwhals are likely between 105 and 125 years old.

Narwhals feed on fish, squid, and shrimp. Predators of the narwhal include killer whales and, to a lesser extent, polar bears and walruses. Inuit hunt them mainly for the ivory tusk and the skin, which is rich in vitamin C. Occasionally, hundreds of narwhals and beluga whales become trapped by pack ice in a pool of open water (savssat in the West Greenland dialect). The whales may then become prey to the local Inuit hunters or die as ice closes the hole.

Narwhals and belugas are related, and together they compose the family Monodontidae of suborder Odontoceti (the toothed whales). The origin of the term narwhal may be the Icelandic words nar, meaning “corpse” (in reference to its pale colour), and hvalr (whale). The scientific name is derived from the Greek words for “single-toothed” and “single-horned,” respectively.

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by John P. Rafferty.

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