Saturday, December 24, 2005

Of course! Narwhal tusk = sensory organ!

` Notice: Since I'm not going to have a working system until after I get back from my trip and will not be able to type many original posts for a while, I will supplement you with stashed drafts in the interim.


` The narwhal ('corpse whale') is a blotchy, blubbery cetacean that is overall not very different from a Beluga whale. As a fetus, the narwhal develops six pairs of upper teeth and two pairs of lower teeth, though all but the top pair are vestigial.

` Typically in adult males - which weigh over a ton - the tooth on the right side of the jaw grows about one foot and remains inside the skull. The other tooth develops into a clockwise-spiraling tusk up to eight or nine feet in length which is actually flexible enough to bend a foot in any direction without breaking.
` Occasionally, in fact, both teeth will become tusks.


` Previously, it has been thought that these dentary wonders evolved for some kind of aggression, but it turns out that they have a more sensitive purpose: The surface of these teeth are embedded with about ten million nerve endings, discovered when two tusks were scanned with an electron microscope.
` Why would animals that live in the partly-frozen Arctic waters have evolved teeth studded with exposed nerves?

` You'd think that would hurt.

` According to Martin Nweeia - the Harvard professor, marine mammal researcher and dentist who did the scans - the tusks can be used for detecting the density of various types of particles, as well as pressure and temperature.

` He was quoted in Scientific American Science News as saying: "The whale has a capacity to dive 400 meters and still understand the particle gradients for salinity in water or prey."
` In other words, the animals should be able to tell the composition of what they're eating, drinking and swimming in to some extent.
` In addition, male narwhals have been observed to affectionately rub their tusks together, and frequently, hold them straight up out of the water.

` Does that mean that these great left teeth play the role of 'grooming organ' and perhaps anemometer?

` I'm sure those questions will be answered in time.

` Personally, I'm kind of struck with how far Western Civilization has come in their perception of the narwhal tusk: A lot of people in medeival times thought that these twisting lengths of ivory were unicorn horns! Now we know they're the sensory organs of intelligent, social sea mammals!
` How times have changed....

` ...Although, if you ask some people, the narwhal is really a "shark with a horn on its forehead." Really, I have heard this, and saying otherwise has no effect. I pity those people. They're the type whose minds would be blown if they visited the narwhal researcher's website, Narwhal.org.
` It's pretty useful if you want to know anything more about the science of these animals and their tusks - unless you're an irritating curmudgeon.

3 comments:

Galtron said...

A tusk? Act as a giant feeler? Who knew?

heather said...

Merry Christmas!!!!

S E E Quine said...

` Thanks. I'll need it.