image courtesy of Jimmy Hu
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Thermoregulatory Adaptations |
| Sea otters possess several adaptations to reduce heat in loss in area with high surface to volume ratios. These parts include their tails and feet. Sea otters tails are significantly smaller than the tails of other otter species, thus reducing surface area. (Tarasoff, 1974) |
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image courtesy of Jimmy Hu |
| Enhydra feet also have reduced surface to volume ratios. Feet are areas of increased heat loss because of their movements during locomotion. When swimming, sea otters' feet move thorugh the water faster than the rest of their body. Thus, they suffer more heat loss to convection. Sea otters have adapted counter current heat exchangers in theri feet to compensate for this loss. (Tarasoff, 1974) |
 picture courtesy of Jimmy Hu |
| Countercurrent
heat exchangers in sea otter legs are similar those found in porpoise fins.
Arteries to the leg are surronded by veins. Before the arteral
blood reaches the leg skin, it is precooled by the cooler veinous blood
traveling back to the heart. Thus, the blodd entering the body is
warmed up and the blood going to the skin is cooled, limiting heat loss
from the surface of the foot.(Schmidt-Neilson, 1998)
In sea otter's, the countercurrent heat exchangers are in the upper part of the leg. There the collateral arteries are closely associated with two large, thin walled veins. Using the pinciple decribed above, the blood is warmed up before re-entering the body and cooled down before entering the leg. This adaptation helps to minimize the heat loss to water in the foot which has less insulation. (Tarasoff, 1974) |
 Sea otter leg displaying veins and arteries. From Tarasoff, 1974 |
| Sea otters use vasocontriction in thermoregulation. Vessels to the skin and periferial parts of the body are contricted, reducing blood flow to those areas. This reduces heat loss by reducing the amount of blood exposed to the skin. (Tarasoff, 1974) |
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other physiological adaptations oil spills and sea otters references |