Which sea whale has a long horn, or tusk, protruding from its head?
And the answer: Narwhal.
Known as Unicorns of the Sea, Narwhals spend their lives in Arctic waters. The Narwhal tusk, found most commonly on males, is an enlarged tooth which grows in the shape of a spiral and can reach up to ten feet in length.
Narwhals are unique among whale species. Its long, ivory tusk actually extends from the upper side of its lower jaw, making it technically a very impressive tooth. But in case you were wondering— no, the Narwhal tusk is not simply the world's sharpest incisor. The tusk is a 7-10 foot tooth is actually packed with 10 million nerve endings. For this reason, scientists have recently come to believe that the tusk may be a sensory organ. Narwhals may use their tusks to detect temperature, water pressure, particle gradients, and motion. In addition, the tusk is flexible, capable of flexing about a foot in all directions.
Like other marine mammals, Narwhals use echolocation — or "bio sonar" — to navigate the frozen waters. Echolocation refer to a series of clicks emitted by the Narwhal, which then reverberate off of their surroundings and allow them to form a reconstruction of their surroundings. Interestingly, recent research suggests that Narwhals are able to piece together small, detailed snapshots of their environment so effectively that they may be capable of the highest resolution reconstruction of any animal on Earth— with the possible exception of the beluga whale. Once the picture has been painted via echolocation, the narwhals can fill in the details, such as the movement of prey or the scent of a mate, using their long, porous tooth.
Learn more about the Unicorn of the Sea here.