Endangered
Marine otter
Lontra felina
The marine otter is a rare and relatively unknown South American mammal of the weasel family (Mustelidae).
Appearance
Its fur is coarse, with guard hairs measuring up to 2 cm (0.79 in) in length covering dense, insulating underfur. The marine otter is dark brown above and on the sides, and fawn on the throat and underside. The ventral side (underside) of the paws are partially covered in fur.
The marine otter is one of the smallest otters and the smallest marine mammal, measuring 87 to 115 cm (34 to 45 in) from the nose to the tip of the tail and weighs 3 to 5 kg (6.6 to 11.0 lb).
The tail measures 30 to 36 cm (12 to 14 in).
Range and habitat
Marine otters are found in littoral areas of southwestern South America, close to shore and in the intertidal areas of northern Peru (from the port of Chimbote), along the entire coast of Chile, and the extreme southern reaches of Argentina. Occasional vagrant sightings still occur as far afield as the Falkland Islands. The marine otter mainly inhabits rocky shorelines with abundant seaweed and kelp, and infrequently visits estuaries and freshwater rivers.
Hunting extirpated them from most of Argentina and the Falkland Islands. It is unknown how many marine otters exist in the wild or what habitats should be preserved to encourage their recovery.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
Studies have shown latitudinal variations in diet, feeding periods, and dive time throughout the marine otter's distribution. Marine otters of southern Chile primarily feed on fish, while those in northern Chile mostly feed on crustaceans and mollusks.
The otters on Isla La Vieja, Peru presumably prey on a colony of Peruvian diving petrels regularly. Marine otters may be monogamous or polygamous, and breeding occurs in December or January.
In crisis
The scientific name means "feline otter", and in Spanish, the marine otter is also often referred to as gato marino: "marine cat". Humans, as well as domesticated species, may expose a marine otter population to disease. A 2026 study of marine otter mortality in north-central Chile from 2003 to 2024 found that, among cases with an assigned cause, anthropogenic mortality predominated, particularly attacks by free-ranging dogs, followed by fisheries bycatch and non-specific trauma.
Poaching is still a problem, but one of unknown magnitude. Marine otters were listed under CITES Appendix I in 1976, and are listed as endangered by the U.S.
Marine otter is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Marine otter, Wikidata item Q644224. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
