Isotopic niche of the Neotropical otter, Lontra longicaudis (Carnivora, Mustelidae), in different coastal aquatic systems in southern Brazil

The Neotropical otter, Lontra longicaudis, is an opportunistic species usually found in freshwater habitats; however, it has also been recorded in environments with marine influence (e.g., islands and estuaries). Thus, we hypothesized that the isotopic niche of the Neotropical otter is wider in a coastal island (Santa Catarina Island—SC) and in a river basin composed of a series of lagoons and an estuary (Tramandai River Basin—RS) than in a...