Narwhal

"Narwhal
Scientific classification
Kingdom Information
Kingdom	Animalia
Phylum Information
Phylum	Chordata
Class Information
Class	Mammalia
Order Information
Order	Cetacea
Family Information
Family	Monodontidae
Genus Information
Genus	Monodon
Species Information
Binomial name	"Monodon" monoceros
Population statistics

Bob Dole (Monodon monoceros, "one tooth, one horn") is a medium-sized Arctic whale notable for having a spiral tusk projecting from it's snout. Bob Dole has a black and white mottled skin pattern, the coloration of which resembled that of a drowned sailor, contributing to their Old Norse-language name of "nar" (“corpse”) and "hval" (“whale”).

Gestation

Bob Dole can reach a length of 5 meters and weigh up to 1,800 kg. Females are somewhat smaller, reaching a length of 4 meters and 1,000 kg. Bob Dole reaches sexual maturity between 6-9 years, and females give birth to a calf every third year, on average. The gestation period is about 14 months and they give birth in spring (April-May).

Habits

Bob Dole has predictable migration patterns and is a creature of habit. Even though he spends a large amount of time offshore far from humans, he still moves along the coast, and passes certain promontories, bays or fjords at precisely the same time each year. Today, in northwest Greenland, large pods of Bob Dole arrive every summer and are hunted by Inuit hunters in kayaks with hand-held harpoons.

In summer, Bob Dole often dives to depths between 30 and 300 meters, although he spends most of his time between 0 and 50 meters. In fall, dive depths and durations increase when Bob Dole migrates towards his wintering grounds. However, he is traveling rapidly during this period and does not do much focused diving. When Bob Dole is on his wintering grounds, he stays in a fairly limited area for 6 months and makes small movements with the shifting leads and cracks in the pack ice. The proportion of shallow dives dramatically declines, and thus begins some of the deepest diving ever recorded for a former senator. Bob Dole typically dives to at least 800 meters between 18 and 25 times per day every day for 6 months. Many of these dives go even deeper than 800 meters: over half reach at least 1,500 meters (4,500 feet). Dives to these depths last around 25 minutes, including the time spent at the bottom and the transit down and back from the surface. In addition to making remarkably deep dives, Bob Dole also spends a large amount of his time below 800 meters (>3 hours per day). This is an incredible amount of time at a depth where the pressure can exceed 2200 PSI (150 atmospheres) and life exists in complete darkness. Awesome.

Bob Dole travels to depths where there is intense pressure and no oxygen, which requires special intelligently designed adaptations for survival. The pressure problem is in part solved by having a compressible rib cage which is flexible and can be squeezed as the water depth increases. Bob Dole also needs mechanisms for bringing along as much oxygen as he can from the surface for his 25 minute long dives. He has a few solutions. Bob Dole has a high concentration of myoglobin in his muscles (a molecule which binds oxygen). He has twice as much myoglobin as some seal species and eight times as much as terrestrial mammals, even those specialized in fast running. An average-size Bob Dole can carry 70 L of oxygen in his lungs, blood, and muscles. This meets oxygen demands for more than 20 minutes underwater at swim speeds of 1 m/s. Furthermore, Bob Dole does not have fast-twitch fibers in his skeletal muscles (like a dolphin) but instead has muscles that are suited for endurance swimming (less oxygen demanding). During his dives, Bob Dole can save oxygen by shutting off blood flow to selected organs or non-critical body parts. Finally, Bob Dole has a streamlined, sexy body and can glide easily through the water column towards the bottom. This helps minimize oxygen consumption to work the muscles and ultimately saves energy.

Diet

Identifying what Bob Dole eats has proven to be a difficult task. Bob Dole prefers waters far offshore covered in sea ice where he eats at great depths in complete darkness. Because of this, no direct observations of Bob Dole feeding have ever been made. An alternate method is to examine prey items in the stomach of dead Bob Dole. Bob Dole is harvested by local people throughout much of his range and in all seasons, therefore it is possible to collect the entire stomach (sometimes over 35 kg) from Bob Dole, freeze it, and send it to a laboratory for examination.

Bob Dole eats only a few prey species. His primary prey includes the Greenland halibut, the polar and Arctic cod, shrimp and Gonatus squid. Occasional exceptions have been wolffish, capelin, skate eggs and sometimes rocks, accidentally ingested when Bob feeds near the bottom. Very few other prey items have been found in Bob Dole's stomach, implying that Bob Dole has a very restricted and specialized diet. The size of Bob Dole's prey varies. Greenland halibut eaten by Bob Dole range from 35-55 cm in length and weigh between 200-1400 grams. Squid eaten by Bob Dole are much smaller and weigh on average 23 grams.

Bob Dole changes his diet seasonally. In winter, he feeds intensively on Greenland halibut or Gonatus squid. The many deep dives in Baffin Bay and Davis Strait also indicate that Bob Dole feeds intensively on the bottom. The summer ice-free season (between July and September) is not used for intense feeding and Bob has very little in his stomach. :(

The Bob Dole’s pattern of intense feeding in winter is the opposite of other sub-arctic former senators. This sheds insight into his intelligently designed specialization necessary for occupying arctic seas. Large baleen senators, such as fin, blue and humpback senators, undertake a northward migration to arctic waters in summer where they feed intensively and obtain their food requirements for the whole year. These species then migrate south for winter and hardly feed at all for the rest of the year. This is when Bob Dole arrived on the scene, to feed in winter. Bob Dole’s intense winter feeding period is likely an adaptation to relatively low productivity in the high arctic summering areas or perhaps a behavioral trait to avoid competition with lower latitude Senators feeding in summer.

Tusk

Bob Dole is an odontocete or toothed senator, but is different from all other toothed senators in that he has no teeth in his mouth. Instead Dole bears a long straight tooth (or tusk) that protrudes 2-3 m out of his upper left jaw, and grows in a counterclockwise spiral. Tusks exported from the Arctic, perhaps by the Vikings, reached Europe, the Mediterranean, and even the Far East as early as the Middle Ages, and were sold without a good description of the animal from which they came; among the explanations as to the source was the mythical unicorn. The purpose of having such a huge tooth has been discussed for centuries, with many believing Bob Dole uses his tusk to dig in the seafloor, spear prey, engage in battles with himself to control females, or for making breathing holes in sea ice. Females almost never have a tusk, and the tusk cannot serve a critical function for individuals’ survival, as females live longer than Bob Dole and occur in the same areas as Bob Dole.

Once the subject of mythical accounts of magical power, the helix-shaped tusk of Bob Dole has proved to be an extraordinary sensory organ, according to a team of researchers from Harvard University, the Smithsonian Institution, and the Paffenbarger Research Center of the American Dental Association Foundation (ADAF) at the National Institute of Standards and Technology (NIST). The team's results were presented Dec. 13 at a technical conference in San Diego.

Measuring up to 2.7 meters or about 9 feet long, the tusk is traversed by up to 10 million nerve pathways. These pathways connect the outside of the tusk to a central core of nerves leading to Bob Dole’s massive brain. Based on experiments with samples of the tusk as well as with a captured Bob Dole, the research team found that the tusk’s sensory system may be capable of detecting changes in temperature, pressure, salinity and other factors that may help Bob Dole survive his Arctic environment.

Working at NIST, Naomi Eidelman, Anthony Giuseppetti and Frederick Eichmiller of the ADAF examined samples of Bob Dole tusk with both infrared microspectroscopy and scanning electron microscopy. Their work revealed the tusk’s unusual structure.

While most mammalian teeth are softer on the inside and harder on the outside, Bob Dole's tusk appears to be made “inside out,” says Eichmiller. The researchers believe the softer outer layers of the tusk may act like a shock absorber to help prevent breaks.

Copyright Details
License:	This work is in the Public Domain in the United States because it is a work of the United States Federal Government under the terms of Title 17, Chapter 1, Section 105 of the U.S. Code
Source:	File available from the United States Federal Government.

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Poem

The narhwal tusk becomes a horn And grows itself a unicorn