Enhydra lutris is in the domain eukarya because it has membrane bound organelles and has a nucleus.  The species’ kingdom is animalia because the sea otter is motile at some point in their life cycle, multicellular, heterotrophic, and also lacks cell walls.  The sea otter is in the phylum chordate because sometime during its life cycle it has a notochord, dorsal nervechord, pharyngeal slits, endostyle, and a post-anal tail.  Sea otters are also bilaterally symmetrical, like all other chordates.  The class is Mammalia because it is a warm blooded vertebrate.  Also the sea otter has sweat glands, hair, and gives birth to their pups live and not from an egg like other members of this class do.  Enhydra lutris is in the order carnivora because this species is a meat eating animal.  The sea otter also has teeth and claws that adapted to the habitat that it lives in along with the animals it consumes.  The sea otters family is Mustelidae because this family contains mostly small animals with short legs, short round ears, and thick fur.  The sea otter fits all of these characteristics and also is active year round like members in this family.  All sea otters belong to the genus Enhydra.  The sea otter is the only member of this genus.  This particular species is given the scientific name of Enhydra lutris.

Domain: Eukarya

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Mustelidae

Genus: Enhydra

Species: Enhydra lutris

This phylogenetic tree for the sea otter contains all the sea otter genera.  The sea otter is the only member of the genus Enhydra.  Each genus is a monophyletic group, meaning that the organisms in each genus share a common ancestor.  The sea otter is sister to the speckle-throated otter (Hydrictis maculicollis) and is by far the closest relative to the sea otter.  This also shows that the sea otter shares a common ancestor with the Eurasian otter (Lutra Lutra), African clawless otter (Aonyx capensis), small-clawed otter (Aonyx cinerea), and the speckle-throated otter (Hydrictis maculicollis).

To learn about the where the sea otter lives click next. 

This page was last updated April 2008.