The function of the narwhal tusk has eluded scientific discovery since the writings of Albertus Magnus in 1495. The long, spiraled tusk, inspiring the legend of the unicorn, has captivated artists, intrigued explorers and baffled scientists. Now, there is preliminary evidence suggesting that the tusk is a sensory organ, detecting gradients of temperature, pressure, particle and ion solutions, and having tactile sensation. The experiment will be completed in 36 degree Arctic waters on captive whales that are part of normal migration tagging efforts in Canada. Variable salt ion solutions will be introduced to a gasket that surrounds a portion of the tusk. As the tusk is exposed to these solutions, brain and muscle activity, heart and pulse rate, and vocal response will be monitored. The results are expected to confirm the micro-anatomic model developed by examining tusks under an electron microscope. The results should confirm overt visual responses observed during the 2007 expedition, of tusk waving immediately after high salt ion solutions were exposed to the tusk surface. The discovery and documentation of this sensory ability will have broad public and scientific impacts. The narwhal may be nature's best detector of global warming, as the ability to sense salt ion solutions is directly linked to ice formation and melting. Furthermore, for tooth tissue development, the narwhal tusk may be the key evolutionary link to several hundred million years ago when armored fish may have been able to detect gradients of temperature, pressure, particles in solution, and tactile events.
