Ichthyofauna diversity in a protected area in the State of São Paulo, southeastern Brazil.

The study site is located in an environmentally protected area known as an "APA" in São Pedro and Analândia, State of São Paulo, southeastern Brazil, whose watercourses are under strong anthropogenic pressure. Two basins were studied (sub-basin of the Corumbataí River and basin of the Jacaré-pepira River) with the purpose of characterizing the ichthyofauna of various streams, comparing fish diversity among assemblages. The Passa-cinco River showed the highest diversity (H'), and the Jaccard and Morisita-Horn indices showed low similarity among sites and between the basins. Diversity was correlated with the number of available habitats and with the environmental conditions.