Title: Narwhals of the Arctic Facts and Adaptations - Monodon monoceros
Headings: Narwhals - Facts and Adaptations
Monodon monoceros

Narwhals - Facts and Adaptations
Monodon monoceros
Medium sized toothed whales with just the single long tusk is present in males and about 15% of females. Animals of the far north and the original unicorns.
What are Narwhals like? how do they survive?
Narwhals live in groups of 10-100 individuals though can sometimes form much larger groups.
Historically
Narwhal Adaptations:

Content: Very occasionally a male will grow two tusks, one from each side though the right tusk also has a left hand spiral rather than being a mirror image as might be expected, around 1 in 500 male narwhals have two tusks. The tusks don't grow out below the lip, they actually grow entirely horizontally in relation to the skull so actually break through the upper lip rather than emerging from the mouth as do other animals tusks. While the tusk is essentially a tooth it has a structure rather different to that of a typical tooth being sort of inside-out with the outside being porous and the hard, usually external enamel layer in the center the opposite way to your teeth. There is a pulp at the very center (like other mammalian teeth) which has blood vessels and nerves and in the order of ten million channels that allow sea-water to enter the tusk. The purpose of the tusk was for a long time unknown or at least unproven. That only males always have fully developed tusks indicates that there is some element of sexual selection in its function in that the tusk somehow enables males to compete for access to females. There is no evidence to show that male narwhals use the tusks to fence in duels with each other as once thought, though males have been seen touching their tusks with other males in non-combative interactions. It is possible that the tusks are largely for show only when it comes to mate selection like a peacock's tail. It has been suggested that they may be used to break ice or spear prey (how will it get it off?) though there is no evidence for either of these things.