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Marine Mammal: The Nawhal Monoceros

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The Narwhal, Monodon monoceros, is a social, specialized deep-water marine mammal characterized by a unique tooth growth protruding from the upper jaw. Narwhals lives along the coasts and rivers throughout the Arctic,characterized by icy ocean temperatures. Narwhals are usually found in groups of 15 to 20, but herds of several thousand have been seen in the Arctic waters since 1871. Regularly found eastwards from the Canadian Arctic to central Russia they have also been distributed throughout the Eurasian Arctic and in an especially high abundance around the oceans west of Cape Farewell on the east coast of Greenland in the summers and during the winter primarily in the Baffian Bay, and in the Canadian archipelago in the springtime (Reeves, Tracey). The Narwhal has two teeth, located in the upper jaw, however only the left tooth usually develops leaving the underdeveloped right tooth in males and typically both teeth in females vestigial (Das). The protruding tusk grows to about 3 meters forward in a counterclockwise spiral pattern (Drury). The distal end of the tusk appears polished, with the remainder commonly covered by a growth of algae. There is an outer layer of cement, an inner layer of dentine, and a pulp cavity that is rich in blood (Reeves, Tracey). The Narwhal’s head and body ranges from 3-6 meters, with the pectoral fin being around 30-40 cm, and the tail flukes expanding over one meter (Reeves, Tracey). The males are typically larger in size than the females averaging about 3,500 pounds in males and 1,000 in females (Drury). Their bodies begin as an uneven grayish hue and as they mature darken to a mottled bluish black color, darker above than below (Reeves, Tracey). Narwhals posses relatively small heads, a blunt sno...

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...ility probably advanced early in the development of life to counter cellular degradation.

Work Cited

Lindahl, Karen, and Susie Balser. "Tardigrade Facts." Tardigrade Facts. Illinois Wesleyan University, 2 Oct. 1999. Web. 20 Feb. 2014.
Das, Darshana, John P. Dafferty, and Grace Young. "Tardigrade (animal)." Encyclopedia Britannica Online. Encyclopedia Britannica, 15 May 2013. Web. 21 Feb. 2014.

Das, Darshana, and John Higgins. "Narwhal (mammal)." Encyclopedia Britannica Online. Encyclopedia Britannica, 20 Dec. 2013. Web. 21 Feb. 2014.
Drury, C. "Animal Diversity Web." ADW: Monodon Monoceros: INFORMATION. University of Michigan, 2002. Web. 21 Feb. 2014.
Reeves, Randall R., and Sharon Tracey. "Monodon Monoceros." Mammalian Species127 (1980): 1. Print.
Wright, J. "Animal Diversity Web." ADW: Tardigrada: INFORMATION. University of Michigan, n.d. Web. 21 Feb. 2014.
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