The river otter is in the Mustelidae family, the Lutra species, and the Canadensis subspecies.  It is from the North American west coast, from Alaska, south to northern California and Utah, on the east coast from Newfoundland to Florida, and around streams and lake borders.  Its head and body are 26-30 inches long and its tail is 12-17 inches long.  A large weasel-like mammal with rich brown hair above and silvery sheen hair below, small ears, a broad snout, webbed feet, and 36 teeth.  It eats fish, crayfish, and other aquatic invertebrates.