Fish species that migrate within thegreat rivers of South America support important localfisheries but are little known outside their native range.This book, written specially for the World Bank and theInternational Development Research Centre, represents thefirst collection of the work of local scientific experts onthese remarkable fish. The authors cover the Upper Parana,Paraguay-Parana, Uruguay and São Francisco basins in Brazil,as well as the Brazilian and Colombian Amazon. They discussnot only the principal migratory species and theirfascinating relationship with the water cycle in the riversand wetlands, but also the fisheries they support, and theiroften precarious conservation status.