If you are anything like me and find yourself intrigued with the unicorns of the sea, “The Narwhal” then you will want to read on to find out some more interesting facts. Often dubbed the Unicorns of the Sea, narwhals are intriguing creatures with large tusks that protrude from the top of their heads. The spiralled tusk can grow as long as 10 feet. They weigh up to 1.5 tonnes and can grow up to 18feet long. It is estimated there are around 170,000 Narwhals worldwide, putting them in the near threatened category and they are found in the Arctic Sea and can live up to approximately 50 years. Their meals mostly consist of arctic cod and greenland halibut. Other fish such as polar cod, cuttlefish, shrimp and armhook squid make up the rest of their diet. Each year, they migrate from bays into the ocean as summer comes. In the winter, the male narwhals occasionally dive up to 1,500 m (4,920 ft) in depth, with dives lasting up to 25 minutes. Narwhals, like most toothed whales, communicate with "clicks", "whistles", and "knocks". The Narwhals Tusk once sold as a “unicorn horn” for exorbitant amounts of money is actually a tooth that has grown through the top of the skull. This is mainly a male feature although has been seen in some females. There are also some “double tuskers” where the males will have two tusks instead of the one, for reasons still unknown. The only teeth Narwhals have are their tusks, inside their mouths they have no teeth at all! The tusk has sensory nerve endings, it is soft on the outside, and gradually gets hard and dense on the inside and has the ability to sense changes in the salinity of the water. So what is the tusk used for? All sorts of ideas have come forward for the purpose of a Narwhals tusk. It could be used as a temperature regulator, a breathing organ, it may be used to detect sound like an acoustic probe. It could also be used as a weapon in battles, or to fend off predators. Other ideas are a digging, ice breaking tool or a way to attract females.. the bigger and more impressive the tusk the more attractive they might be to the opposite sex? Not a lot of study has been done on Narwhals due to their elusive and shy nature. Cartoons sometimes suggest that narwhals are fierce creatures, perhaps duelling with their tusks. However this is not what’s been observed in a recent study led by a team that included marine and developmental biologists, comparative zoologists, dentists, and orthopedic surgeons in 2014. It was perhaps the most detailed and high-tech analysis of the tusk ever attempted and concluded that the tusk is a highly sensitive organ. On encounters with the Narwhals they were described as beautiful and quite graceful. “Narwhals were also seen to be shy and skittish. Which is not particularly surprising, as humans have hunted them for centuries. Today, the inuit hunt them under carefully-managed quotas, a practice that " is important culturally and from a dietary perspective," says Westdal – a biologist specialising in Arctic Marine Mammals. The hunting is not a threat to the species, but noise might be. As the arctic sea ice retreats due to global warming, ever more shipping is passing through the arctic, and that means it is getting noisier. That could be a problem for narwhals, being whales, they communicate using sound: specifically, buzzy clicks, squeaks like a creaking door and strange whistles. They also use sonar to navigate. It is possible that all the extra noise will force them out of important habitats. Alternatively, they might shrug it off. "We don't know the answers to this at all," says Westdal. Preferring not to wait, conservationists are already trying to protect critical areas like Lancaster Sound, which most of the world's narwhals pass through every year. lesley evans ogden bbc.com/earth/story Here are some truths about Narwhals : The common name narwhal literally means “corpse whale,” in reference to its pale body colour, which shades from a light grey on the lower flanks and underside to a dark and dappled grey on its back. The narwhal is most closely related to the Beluga Whale. Together, these two species comprise the only extant members of the family Monodontidae, sometimes referred to as the "white whales". Even though the Narwhal is closely related to the Beluga there is some evidence that they may, very rarely, interbreed to create a narwhal-beluga hybrid. At times, a bull narwhal may rub its tusk with another bull, a display known as "tusking” to maintain social dominance hierarchies. Narwhals belong to the group of animals known as toothed whales (even though they don’t have any teeth in their mouth! Only their tusk). Narwhals can dive up to 1500m and stay under water for at least 25mins per dive. They may dive up to 15 times a day at a depth of at least 800m. Narwhals are affected and threatened by climate change. Narwhals are affected by noise pollution which is highly disturbing to their communications. Narwhals can be lethally entrapped by rapidly forming fast ice. About 1000 narwhals died in an ice entrapment in Canada in 2008 and about 100 in two entrapments in Northwest Greenland in 2009–10. Narwhals can be threatened by seismic testing and more studies are urgently needed. Inuit-indigenous people of the Arctic have long hunted Narwhals for food and for the ivory of their tusks. Other causes of death, specifically among young whales, are starvation and predation by Orcas and Polar Bears.