Variation of local zoological knowledge about Southern river otter and other semi-aquatic mammals in Nahuel Huapi National Park (Argentina).

Background: The huillín (Lontra provocax, Thomas 1908) is an otter, endemic to southern Argentina and Chile. It is in danger of extinction. In the Nahuel Huapi National Park and surroundings is the only freshwater, known and stable population of huillín in Argentina.

A new microphallid (Digenea) species from Lontra provocax (Mammalia: Mustelidae) from freshwater environments of northwestern Patagonia (Argentina).

A new microphallid species of Maritrema is described from the native southern river otter, Lontra provocax (Thomas). A naturally infected otter was found dead in the Nahuel Huapi National Park, Argentina. Ovigerous adult worms were recovered from the anterior portion of the intestine.