The invasive submerged macrophyte Hydrilla verticillata as a foraging habitat for small-sized fish

Several species of aquatic macrophytes have invaded ecosystems outside their ranges, producing a variety of impacts on native biota. In this study, we tested the role of the invasive macrophyte Hydrilla verticillata as a foraging habitat for small fish species. To achieve this goal, we assessed the feeding activity and diet composition of fish captured in patches of the invasive H. verticillata and of a similar native macrophyte (Egeria najas). Feeding activity did not differ significantly between H. verticillata and E. najas, indicating that foraging activity was not affected. However, differences in diet composition were significant in three out of five fish species and marginally significant in one species, suggesting that the invasive and native macrophytes provide different types of food resources for fish. Thus, although H. verticillata does not affect the foraging activity, it has the potential to affect the assemblages of small-sized fish through changes in the proportions of food resources. © 2014 Associação Brasileira de Ciência Ecológica e Conservação. Published by Elsevier Editora Ltda.