 Reservoirs have been built in almost all of the hydrographic basins of Brazil. Main impact is the change from Lodic to Lentic water, which influences aquatic fauna, including fishes. Most affected species are the rheophilic and long-distance migratory that require distinct habitats to fulfill their life cycles. This article was authored by A.A. Augustino, F.M. Pelicis, and L.C. Gomez.