narwhal

The narwhal (Monodon monoceros) is a species of odontocete cetacean of the family Monodontidae that inhabits the seas of the Arctic and northern Atlantic Ocean. It is the only member of the genus Monodon and one of two species in the family along with the beluga whale (Delphinapterus leucas).

The males of this species are characterized by a very long, helically twisted tusk that can reach a length of two meters and weigh up to ten kilograms (at the Rocsen Museum in Nono, province of Córdoba in the Argentine Republic they have a 270 cm tusk that according to the founder Juan Bouchon is the largest in the world [citation needed]). It is believed that this specialized tooth may be a sensory receptor or secondary sexual character.

This species is adapted to live in the Arctic and feeds on animals on the seafloor. It lacks a dorsal fin and has a medium size among cetaceans, with an average adult length ranging between 4 and 4.5 m and a weight of between 1000 and 1600 kg. Its diet is restricted to only a few fish and crustaceans, which it feeds primarily during the winter months, when it consumes a large volume of prey that it catches on the seabed. To do so, it must make dives that very often exceed 800 m below the surface, which can last up to 30 minutes. After the sperm whale, beaked whale and elephant seal, it is the marine mammal that dives the deepest.

It is distributed mainly in waters of the Arctic region of northern Canada, the seas on the Russian side of the Arctic Ocean and north of the Atlantic Ocean. It mainly inhabits around ice shelves that form during prolonged Arctic winters, migrating to circumpolar bays and fjords during the summer. The world population is believed to number just over 75,000. In 2008 it was listed on the IUCN Red List as Near Threatened, due to significant, controlled hunting by the Inuit people in Canada and Greenland (Denmark), who benefit from its meat, fat and tusk trade. It was also placed in this category because of the evident decline in the population of some groups, the lack of certainty about the total number of animals, and the lack of knowledge of growth trends.

Other threats to the population of this cetacean are: predation by their natural enemies (sharks, polar bears and killer whales), contamination by pesticides and heavy metals, entrapment in dense layers of ice at the beginning of winter, which prevents them from moving to the open sea and dying of starvation and drowning, and the low capacity to adapt to climate change.