A large otter with a very, very long tail (hence the latin name), the Neotropical River otter seems to have a large distribution but an unknown population size. It is a versatile otter that is found in many habitats – one sighting in Chile was made at 3885 m above sea level! Sympatric with the giant otter, it has different habits and preferences – they seem to ignore each other.

The Neotropical River otter may be diurnal or nocturnal and hunts fish, crustaceans, sometimes small mammals, birds, reptiles and insects. It is sometimes kept as a pet by fishermen and trained to help them corral fish into nets.

Between the 1950s and the 1970s, an extremely high hunting rate nearly drove this little mustelid nearly into extinction when over 30,000 otters were killed every year for their pelts. Now, they are protected in every country in which they occur.