User:Mjoh364/Sea Otter

Description
Unlike most other marine mammals, the sea otter has no blubber and relies on its exceptionally thick fur to keep warm. With up to 150,000 strands of hair per square centimetre (nearly one million per sq in), its fur is the densest of any animal. The fur consists of long, waterproof guard hairs and short underfur; the guard hairs keep the dense underfur layer dry. There is an air compartment between the thick fur layer and the skin where air is trapped and is heated by the body .Cold water is kept completely away from the skin and heat loss is limited. '''However, this air compartment can be disadvantageous because as the sea otter dives deeper into the water column, the air compartment compresses and heat needed to warm the body is lost. .''' The fur is thick year-round, as it is shed and replaced gradually rather than in a distinct molting season. As the ability of the guard hairs to repel water depends on utmost cleanliness, the sea otter has the ability to reach and groom the fur on any part of its body, taking advantage of its loose skin and an unusually supple skeleton. The coloration of the pelage is usually deep brown with silver-gray speckles, but it can range from yellowish or grayish brown to almost black. In adults, the head, throat, and chest are lighter in color than the rest of the body.

Diet
'''High energetic requirements of sea otter metabolism require them to consume at least twenty percent of their body weight a day. Foraging and surface swimming are major factors in their high energy expenditure due to drag on the surface of the water when swimming and the thermal heat loss from the body during deep dives when foraging '''.

Sea otters consume over 100 prey species. In most of its range, the sea otter's diet consists almost exclusively of marine benthic invertebrates, including sea urchins, fat innkeeper worms, a variety of bivalves such as clams and mussels, abalone, other mollusks, crustaceans, and snails. Its prey ranges in size from tiny limpets and crabs to giant octopuses. Where prey such as sea urchins, clams, and abalone are present in a range of sizes, sea otters tend to select larger items over smaller ones of similar type. In California, they have been noted to ignore Pismo clams smaller than 3 inches (7 cm) across.