IUCN Otter Specialist Group . . . leading global otter conservation Last Update: Sunday February 22, 2015
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Lontra longicaudis (Olfers, 1818), the Neotropical Otter(currently being revised)

:: Lontra longicaudis

Click on the images below to see more of this species
Neotropical River Otter in the water, looking up at the camera
Two neotropical river otters
A neotropical river otter, showing the long tail
Neotropical Otter in Panama, by Asheley Hennes

More photos would be welcome



The Neotropical otter is part of the Mustelidae family (weasel, polecat, wolverine, tayra). This is an average sized, robustly built otter, very similar in appearance to the other American river otters. The tail can be notably long, forming more than a third of the body length. They are around 1.2-1.5m long (in some places males can reach 1.75m), usually weighing 7-15kg (in some places males can reach 25kg). The species shows sexual dimorphism - the male is generally 20-25% larger than the female. Apart from the longer tail, these otters look like Southern and North American River Otters, and for a long time, the relationships between the species were obscure, and many species previously identified are now considered subspecies and local races. Rhinarium shape varies a great deal. This species does not appear to be social. The female only tolerates the male during oestrus, and, like the Eurasian Otter, groups of otters seen together appear to be females with cubs. The main prey of the Neotropical Otter is fish (slow moving or easy to catch, conspicuous and palatable), followed by crustaceans. Insects and frogs become very important in the diet if the main prey species decrease in numbers.

CITES Identification Sheet


These versatile otters are found in a very wide variety of environments, always associated with the presence of water: permanent, seasonal and intermittent rivers, streams and creeks, freshwater lakes, marshes and pools, saline, brackish or alkaline lakes, marshes and pools, shrub-dominated wetlands, geothermal wetlands, permanent inland deltas , shallow bays, rocky shores, estuaries, intertidal marshes, coastal freshwater, brackish and saline lagoons, reservoirs, ponds, fish farms, excavations, wastewater treatment areas, seasonally flooded and irrigated agricultural land, canals, drainage ditches (such as among rice and sugar cane plantations in Guyana), bogs, fens, swamps and peatlands. They can live in evergreen and deciduous forests, in warm and cool climates, by the sea or in the rainforest. They have been seen in the swampy areas of cushion plants and sedges surrounding glacial lakes in the High Andes of Ecuador at an altitude of 3885m.


The species ranges from northern Argentina up through south and central America to Mexico. There is then an otter-free arid zone between it and the North American River Otter.

Conservation Status

Red List Category DD Near Threatened, Decreasing
Year Assessed 2014
Assessor Rheingantz, M..
Evaluators Hussain, S.A. (Otter Red List Authority)

The species seems to be widespread, and its range does not seem to have changed, but there is no data available about population size, composition or distribution, so changes cannot be determined.

(Source: IUCN Red List)

Current Concerns

There are two major threats to the species in Latin America: habitat destruction and water pollution. This otter was declared a protected species in 1973, however, it is still being hunted illegally, mainly by fishermen.

Leading Researchers

Marcelo Rheingantz, Cristine Trinca, Helen Waldemarin, Juan Pablo Gallo-Reynoso

Key Publications


  • Harris, C.J. (1968). Otters: A Study of the Recent Lutrinae. Weidenfeld and Nicholson, London
  • Larivière, S. (1991) - Lontra longicaudis. Mammalian Species, 609:1-5.


  • Pardini, R. (1998). Feeding ecology of the neotropical river otter Lontra longicaudis in na Atlantic Forest Stream, south-eastern Brazil.  Journal of Zoology 245: 385-391.
  • Pardini, R. & Trajano, E. (1999). Use of shelters by the Neotropical river otter (Lontra longicaudis) in an Atlantic forest stream,  southeastern Brazil.  Journal Of Mammalogy 80(2): 600-610.
  • Waldemarin, H.F. & Colares, E.P. (2000). Utilization of resting sites and dens by the neotropical river otter (Lontra longicaudis) in the south of Rio Grande do Sul State, Southern Brazil. IUCN Otter Specialist Group Bulletin 17(1): 14-19.
  • Quadros, J. & Monteiro-Filho, E.L.A. (2001). Diet of the Neotropical otter, Lontra longicaudis, in Atlantic Forest area, Santa Catarina State, southern Brazil. Studies on Neotropical Fauna & Environment 36(1): 15-21.
  • Gori, M.; Carpaneto, G. & Ottino, P. (2003). Spatial distribution and diet of the Neotropical otter Lontra longicaudis in the Ibera Lake (northern Argentina). Acta Theriologica 48(4): 495-504.
  • Kasper, C.B.; Feldens, M.J.; Salvi, J. & Grillo, H.C.Z. (2004). Estudo preliminar sobre a ecologia de Lontra longicaudis (Olfers) (Carnivora: Mustelidae) no Vale do Taquari, Sul do Brasil.. Revista Brasileira de Zoologia 21(1): 65-72.


  • Trinca, CS.; Waldemarin, H.F. & Eizirik, E. (2007). Genetic diversity of the Neotropical otter (Lontra longicaudis Olfers, 1818) in Southern and Southeastern Brazil. Brazilian Journal of Biology 67(4): 813-818.

Useful Links

Revised by Marcelo Rheingantz, July 2009