Scientific classification: Otters belong to the family Mustelidae. The otter of Europe and Asia are classified as Lutra lutra. The North American otter is classified as Lutra canadensis.
Introduction
Otters are aquatic carnivore found worldwide except in Australia, New Zealand, and Antarctica. In the common species distributed throughout Europe and Asia, the body may attain a length of 75 cm (30 in), with a tail half as long as the body. The head is broad and flat, with short, rounded ears; the blunt snout bears lateral, otter attack slitlike nostrils. The ears and nostrils can be closed when the animal is diving. The fur is chestnut, the legs are short but strong, and the webbed feet have claws. A similar species is found in North America. An otter species found in South America, known as the giant otter, reaches about 1.8 m (6 ft) in length.
Characteristics
Otters live in dens, usually by the side of water and with an underwater entrance to the den. They feed on fish and also on small mammals, birds, frogs, and crayfish. The animals breed in the spring, and authorities have reported a gestation period of about 61 days for the species already mentioned. Certain investigators have also observed delayed implantation in the North American species, with a gestation of almost 12 months. Development still lasts only two months, however, since almost no development occurs between mating and the time when the fertilized eggs are implanted in the uterus. The litters range from one to five pups, otter attack which stay with the mother for about a year. See also Sea Otter.
Physical description
The sea otter is the smallest of all marine mammals. The body of an adult otter reaches a length of about 1 to 1.2 m (about 3.3 to 4 ft), and the tail extends another 30 cm (12 in). Males generally weigh about 29 kg (65 lb), and females 20 kg (45 lb).
The sea otter uses its large hind feet and rudderlike tail for propulsion in the water. The hind feet look like broad flippers, otter attack, with webbed toes. The forefeet have semi-retractable claws, similar to those of the paws of a cat.
The sea otter’s fur is the thickest of any mammal, with about 150,000 hairs per sq cm (about 600,000 hairs per sq in). The fur color varies from reddish brown to dark brown. The head, throat, and chest are lighter, in shades of cream or gray.
Reproduction
Female sea otters reach sexual maturity between 2 and 5 years of age. Males usually do not become active breeders until they are more than 5 years old. Sea otters generally live 10 to 20 years, with females living slightly longer than males.
Males and females stay mostly separate except when they meet briefly for courtship and mating. A mating pair usually bonds for about three days. Some males establish territories in female areas and mate with multiple females. Females may have more than one male partner as well. Mating takes place entirely in the water. A male usually bites the female on the nose during their encounter, otter attack, so one way to identify a female is by a badly scarred nose.