Ecomorfologia trófica de Psalidodon paranae (Eigenmann, 1914) em riachos com diferentes graus de antropização

Abstract

This study analyzed the trophic ecomorphology of the species Psalidodon paranae in three streams with different levels of anthropogenic impact (urban, peri-urban, and rural) located in Londrina, Paraná, Brazil. The central hypothesis considered that Psalidodon paranae populations would exhibit trophic and ecomorphological differentiation according to the environmental impacts of each stream. To test this, limnological, morphometric, ecomorphological, and trophic analyses were carried out, combined with multivariate statistical analyses such as PCA, PERMANOVA, PERMDISP, and RDA. The dietary analysis indicated that individuals from all streams mainly consumed aquatic macroinvertebrates, terrestrial insects, and animal remains. Cambé Stream showed greater exploitation of autochthonous resources such as phytoplankton and algae, while Cafezal and Taquara streams presented a higher consumption of allochthonous resources. PERMANOVA and PERMDISP analyses revealed that despite differences in dietary composition, there were no significant differences in niche breadth among the streams. The Principal Component Analysis (PCA) applied to the ecomorphological indices showed that only the first axis was significant, indicating that most of the morphological variation occurs within the streams themselves rather than among them, reinforcing the absence of expressive morphological differentiation. Furthermore, the RDA analysis demonstrated that trophic and ecomorphological variations are subtly associated with environmental gradients, indicating that the species has high morphological and trophic plasticity, which favors its persistence in environments with different levels of degradation. It is concluded that, although there are tendencies in resource use, the environmental pressures associated with anthropization were not sufficient to generate significant differentiation in the ecomorphological characteristics and trophic niche breadth of the species among the evaluated streams, demonstrating its ecological resilience.