All otters belong to the family Mustelidae, along with weasels, skunks, minks, and badgers. Mustelids are characterized by generally long, streamlined bodies; fine, dense hair; and scent glands at the base of the tail.
Species in the genus Aonyx have digits that are either clawless or have very small, often blunt claws.
Genus - Enhydra (sea otter).
sea otter (Enhydra lutris)
Sea otters are further divided into three subspecies: E.l. lutris - the Russian or Asian sea otter; E.l. kenyoni - the northern or Alaskan sea otter; and E.l. nereis - the southern or California sea otter. The subspecies are separated geographically, and vary slightly in their size, diet, use of tools, and the amount of time they spend on land.