“We are all here today to talk about a tooth,” Dr. Martin Nweeia, a dentist from Sharon, Conn., said to a captive audience at The Maritime Aquarium Monday night.
For more than an hour, he spun tales of his encounters with “the unicorn of the sea”: the mysterious and rarely seen narwhal.
As a dentist by trade, Nweeia’s side job is one most patients would least expect. When he’s not drilling or cleaning, he spends months at a time on research missions in the Arctic; to the point that he has become one of the world’s leading experts on narwhals.
Nweeia’s initial interest in the tusked Arctic whale, which is closely related to the beluga, and its unique orthodontics began superficially enough. The narwhal’s single tusk is actually one giant exposed tooth, which can reach up to 9 feet in length and up to half the length of the narwhal’s body.
“It’s a tooth. I’m a dentist. Maybe I’m the right guy!” he said, recalling his initial foray into narwhal research.
With support from Harvard University and the Smithsonian Institution, Nweeia has spent the past 14 years studying what he calls “the most extraordinary tooth in all of nature.”
The tooth, which typically grows out of the left side of the males’ upper lip, actually pierces through its skin and is as strong as it is flexible. It has been known to flex up to a foot in any direction, but can withstand large amounts of force. It is also the only straight and spiraling tusk in nature.
Narwhals, whose scientific name means “one tooth, one horn,” aren’t aptly named, especially because their tusk is not a horn, Nweeia said, explaining that he much prefers the more poetic Inuit translation: “The one that points its tooth to the sky.”
The function of the tusk, which he described as a bundle of exposed nerves, has remained a mystery to scientists. The pursuit of explaining its peculiar dentistry has been at the heart of Nweeia’s decade and a half of research.
Dismissing a common theory about narwhals, Nweeia doesn’t believe the tusk is used between males to assert dominance, such as seen in instances of “sword fighting.” Rather, his findings suggest that the whales use their porous and extremely sensitive tooth to sense changes in temperature and barometric pressure, fish and other food, changing salinity levels in the water, and migration patterns.
What Nweeia has discovered throughout his many treks to the Arctic Circle is that they are unlike any other toothed whales. Namely, the tusk is normally its only exposed tooth – it has none whatsoever inside its mouth. Rarely, a narwhal will exhibit two tusks protruding from its lip.
Even stranger, narwhals COULD have teeth, but their bodies reject them. According to Nweeia, while narwhal fetuses develop, they have eight pairs of teeth, which are genetically silenced at birth. However, they do have a total of four teeth: the erupted tusk, an embedded tusk and two vestigial teeth, which are embedded in their skulls and have likely been rendered obsolete during the narwhals’ evolution.
The whales remain largely unstudied, and Nweeia hopes to meld traditional knowledge, largely gathered by Inuits he works with in the Arctic, with scientific research to better understand all facets of the narwhal population.
Four events remain in the Aquarium’s 2013-14 lecture series:
• Dr. Patricia Wright, the scientist featured in the new IMAX movie “Island of Lemurs: Madagascar,” on Thurs., April 17.
• Zookeeper/ TV host Jack Hanna for two shows on Tues., May 7.
• and Weston, CT, author Richard Hyman, who will talk about his expeditions aboard Jacques Cousteau’s Calypso, on Mon., June 23.
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