Did you know there’s a whale with a horn like a unicorn?

The narhwal (Monodon monoceros) is an arctic whale, closely related to the beluga whom it resembles.

Like the beluga, it has teeth though it doesn’t use them for chewing.  All but two of the teeth are vestigial but one of those, the left canine, grows though the male’s upper lip spiraling counter-clockwise, straight out, in a single tusk as much as nine feet long.

The tusk is not a sword.  Instead, like our teeth it’s made up of layers but it’s hollow inside and much more sensitive.  The outer layer is permeable, allowing seawater to pass through the dentin into the hollow core filled with millions of nerves. Scientists know the tusks can sense salinity but they probably can sense a lot more. When narwhals surface to breathe and rub tusk to tusk they’re not fighting, they’re communicating.

Narwhals are so specialized it may lead to their extinction.  They live only in the Arctic Ocean where they depend on its icy habitat for food and shelter.  They roam in pods of 5-10 individuals and may migrate in groups of 1,000 but they seem more loyal to their favorite sites than to following their food.  As climate change heats the water and melts the arctic ice, narwhals will have less food and fewer places to live. Like the polar bear, narwhals are threatened by climate change.

If or when this whale goes extinct it may pass into mythology, like the unicorn.

(photos from Wikimedia Commons. Click on the images to see the originals)