Dispersal potential of aquatic invertebrates via endozoochory by semiaquatic mammals in Neotropical wetlands

Abstract

Abstract Aquatic invertebrate dispersal is crucial for maintaining connectivity among wetlands, yet mechanisms across fragmented landscapes remain poorly understood. Here we analyzed 68 fecal samples from three Neotropical semiaquatic mammals—the capybara, coypu, and Neotropical otter—in southern Brazil to assess their role in dispersing aquatic invertebrate propagules. A total of 5444 propagules from 12 distinct invertebrate taxa were recovered from 68 fecal samples: nine from capybaras, 31 from coypus, and 28 from otters. Nematodes were the most abundant taxon overall (5146 individuals), both across all samples and within each mammal species. Excluding nematodes, a total of 298 propagules from 11 taxa recovered from 48 fecal samples was observed. We identified 298 propagules from 11 taxa, including viable eggs, resting stages, and live individuals. Invertebrate assemblages differed significantly among mammal species, with variation primarily driven by taxa such as Heleobia, Plumatella, and Ephydatia facunda. These findings reveal that semiaquatic mammals may contribute to linking aquatic ecosystems through the terrestrial matrix, suggesting their movements may support invertebrate metacommunity dynamics and wetland biodiversity maintenance more broadly than previously recognized.