The influence of the longitudinal gradient on fish assemblages in a neotropical river: exploring the functional and taxonomic diversity in different stretches of the Mogi-Guaçu river

• Grant number: 13/27200-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2014
• End date: October 31, 2016
• Field of knowledge: Biological Sciences - Ecology
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Marlene Sofia Arcifa Froehlich
• Grantee: Fabio Teruo Mise
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Different stretches of Mogi-Guaçu river (headwaters, medium and inferior), São Paulo State, Brazil, will be sampled in order to study the influence of the longitudinal gradient on fish assemblages on a Neotropical basin. The differences in fish assemblages from distinct portions of the basin will be verified using taxonomic and functional beta diversity. Two components of beta diversity, turnover and nestedness, will be addressed to verify whether the differences between the assemblages are due to replacement or addition of species. Functional traits will be related to occupation of habitats, feeding habits and reproduction. Morphologic data will be used to predict the occupation of habitats according to ecomorphological studies. Null models will be used to test if the functional patterns of the assemblages are different than expected by chance. This will be made with the intention to verify if there is a factor responsible for structuring these assemblages. At last a RLQ will be performed in the different parts of the basin to check if there is a relationship between functional traits and environmental variables. In summary the proposed hypotheses are: I) taxonomic and functional beta diversity increase towards the headwaters-mouth way; II) the importance of the beta diversity components (turnover and nestedness) change along the longitudinal gradient; III) the patterns of functional diversity in each stretch of the river are not at random; IV) there is a relationship between functional traits and environmental variables. (AU)