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Overview
Brief Summary
Description
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Mammal Species of the World
- Original description: Van Gelder, R.G., 1959. American Museum Novitates. 1973:2.
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Description
Links:
Mammal Species of the World
- Original description: Mearns, E.A, 1890. Description of supposed new species and subspecies of mammals, from Arizona. Bulletin of the American Museum of Natural History 4:277-307.
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Description
Links:
Mammal Species of the World
Click here for The American Society of Mammalogists species account
- Original description: Merriam, C.H., 1907. Descriptions of ten new kangaroo rats, p. 77. Proceedings of the Biological Society of Washington, 20:75-80.
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Description
Links:
Mammal Species of the World
Click here for The American Society of Mammalogists species account
- Original description: Grinnell, J., 1919. Five new five-toed kangaroo rats of California, p. 43. University of California Publications in Zoology, 21:43-47.
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Comprehensive Description
Description of Animalia
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Description of Animalia
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Physical Description
Size
Size in North America
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Size in North America
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Size in North America
Length:
Average: 326 mm males; 323 mm females
Range: 310-336 mm males; 305-323 mm females
Weight:
Average: 85 g
Range: 79-91 g
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Size in North America
Length:
Range: "1,300-1,700 mm "
Weight:
Range: 20-38 kg males; 18-30 kg females
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Ecology
Associations
Known predators
Rissa
Cepphus
Fratercula
Fulmarus glacialis
Alle alle
Somateria
Gavia stellata
Clangula hyemalis
Phocidae
Based on studies in:
Norway: Spitsbergen (Coastal)
This list may not be complete but is based on published studies.
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Associations
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Evolution and Systematics
Functional Adaptations
Functional adaptation
Defensins are naturally produced peptides that inhibit pathogen growth and degrade pathogen toxins by binding to the pathogens
“In addition to their bacterial membrane permeabilizing capacity, defensins have been shown to neutralize bacterial invasion by directly binding to bacterial toxins….Similar properties have been described for retrocyclins, a class of circular defensins found in non-human primates, which were shown to bind to the anthrax lethal factor with high affinity [66].” (de Leeuw and Lu 2007:69)
Learn more about this functional adaptation.
- de Leeuw, E.; Lu, W. 2007. Human defensins: turning defense into offense?. Infectious Disorders Drug Targets. 7(1): 67-70.
- Zou, G.; De Leeuw, E.; Li, C.; Pazgier, M.; Li, C.; Zeng, P.; Lu, W-Y.; Lubkowski, J.; Lu, W. 2007. Toward understanding the cationicity of defensins. The Journal of Biological Chemistry. 282(27): 19653-19665.
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Functional adaptation
Mucins of animals stop invading pathogens by being coated with sugar chains that trap the invaders.
"Researchers at the University of Massachusetts and Yale University are looking for ways to trap viruses. In order to reproduce, viruses need to invade a host cell and replicate using the cell's own DNA-replication system. The researchers figured that if they could lure viruses to decoy cells, they could reduce the viral load enough for someone with HIV or other disease for that person's own immune system to successfully fight off the attack. Mucins are proteins found in most body fluids. They are coated with sugar chains that trap invading pathogens. Red blood cells also appear to act as pathogen traps. One approach is to coat nanoparticles with viral receptors. Another approach is to add decoy attachment sites to red blood cells. One advantage of using viral traps is it would be hard for viruses to evolve resistance to them." (Courtesy of the Biomimicry Guild)
Learn more about this functional adaptation.
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Functional adaptation
The metabolism of animals oxidizes fat-soluble organic chemicals into excretable water-soluble substances, via P450 enzymes.
"The number of P450 genes cloned from various organisms such as animals, plants, yeasts, fungi, bacteria and sequenced is presently over 2000 and still increasing…P450s are major enzymes in drug metabolism in animal tissues and organs because they convert the pharmaceutics to more hydrophilic metabolites which are easily excreted into urine." (Hara 2000:103)
Learn more about this functional adaptation.
- Hara, Masayuki. 2000. Application of P450s for biosensing: combination of biotechnology and electrochemistry. Materials Science and Engineering: C. 12(1-2): 103-109.
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Functional adaptation
The arterial walls of many animals resist stretch disproportionately by incorporating non-stretchy collagen fibers in a particular arrangement.
"In effect, Laplace's law rules out the use of ordinary elastic materials for arterial walls, requiring that an appropriate material fight back against stretch, not in direct proportion to how much it's stretched, but disproportionately as stretch increases. Which, again in obedience to the dictates of the real world, our arterial walls do--aneurysms, fortunately, remain rare and pathological. We accomplish the trick first, by incorporating fibers of a non-stretchy material, collagen, in those walls, and second, by arranging those fibers in a particular way. Thus, as the wall expands outward, more and more of these inextensible fibers are stretched out to their full lengths and add their resistance to stretch to that of the wall as a whole." (Vogel 2003:7-8)
Learn more about this functional adaptation.
- Steven Vogel. 2003. Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.
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Functional adaptation
Aquatic organisms move effectively through water by maximizing propulsion efficiency.
"It [the Froude propulsion efficiency] says that for highest efficiency, the velocity of the fluid issuing from the propulsive unit--paddle, propeller, jet, or whatever--should be as close as possible to the velocity of the craft...Clearly the way to maximize Froude propulsion efficiency consists of moving the largest possible mass-per-time (m/t) of fluid and giving it the least possible increase in speed (v2-v1). In practical terms that means maximizing S, the cross section of the propulsive flow stream."
While the Froud efficiencies "vary in quality and involve differenty underlying assumptions and simplifications, the picture that emerges is satisfyingly consistent with our expectations."
"* Moving water with undulating body, beating wing, or swinging tail beats squeezing water out of a jet, as anticipated. A squid may jet fast, but when it wants to go far, it's more likely to use its fins.
"* The same undulating devices do better than systems that move water back-wards with a paddling system, with its alternating power and recovery strokes. We'll return to this comparison between 'lift-based' and 'drag-based' propulsion in chapter 13.
"*Bigger (or at least moderate size) is better than smaller. Except for one questionable datum for a bacterial flagellum, no creature below about a centimeter in length does better than ηf = 0.5. The pernicious effects of low Reynolds number (chapter 11) cannot be denied.
"*The broad hydrozoan medusae (essentially small jellyfish) may use jet propulsion, but they do it by pushing out an especially large volume (relative to their own) through a wide aperture. So they have a much higher m and lower v2 than the other jetters, and thus evade most of the difficulty inherent in equations (7.5) and (7.6)." (Vogel 2003:142-143)
Learn more about this functional adaptation.
- Steven Vogel. 2003. Comparative Biomechanics: Life's Physical World. Princeton: Princeton University Press. 580 p.
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Conservation
Conservation Status
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