Head-body 50-82 cm; tail 35-38 cm; weight 5-6 kg.
The presence of entirely hairy nose and rhinarium (moist part of nose),
which being naked in other coexisting otter species makes this otter easy
to be recognized at close range, and its dark chocolate pelage with slightly
paler underpart in the field. Upper lip, chin and throat sharply-demarcated
white. Head flattened considerably than those of other otters. Tail flattened
and oval in cross section. Feet well-webbed and armed with strong claws.