9615620 Vanni The major premise of this research is that sediment-feeding and algivorous fishes and amphibians are important ecological engineers in tropical streams, and can generate significant resource heterogeneity over a variety of spatial and temporal scales. Specifically, this research will examine whether the diverse guild of epibenthic-feeding fishes is ecologically redundant, and whether species identities are important to stream community and ecosystem dynamics including the generation of resource heterogeneity. The main objective of this research focuses on the importance of biodiversity, species identities, and density to resource heterogeneity, community and ecosystem dynamics. A series of experimental and observational tests will be used to address this main objective. This study will provide insight into the importance of biodiversity to the structure and function of stream communities. The proposed research will further our knowledge of community and ecosystem roles of sediment feeding and algivorous fishes, and demonstrate whether these organisms vary significantly in their capacities as ecological engineers. Sediment and algal-feeding fish are among the most important components of the freshwater fisheries throughout South America, yet their ecology is very poorly known. Overall, this project will broaden our limited knowledge of patterns and processes in tropical stream communities.
