Structural variation of stream freshwater fishes metacommunity from Atlantic Forest

Abstract

Several factors influence stream ichthyofauna structure (e.g. habitat heterogeneity, spatial scale and dispersal) and the metacommunity framework can help to understand the mechanisms and process which regulates spatial organization of species, as this concept is focused on interaction linking dispersal and community dynamics within and between local and regional scales. The aim of this study is to determine how much of the environmental and spatial variables (local and regional factors, respectively) explain the variation of fish community structure from Juréia-Itatins reserve, considering the metacommunity theory. In a previous study at this site, it was found that the habitat structure (i.e. depth, stream flow, and bottom type) can influence the diversity of fish species, but there was evidence that the altitudinal gradient and the isolation between the streams are spatial factors that may also be responsible for the organization of this ichthyofauna. Fifty nine sites distributed in upper, middle and lower stream stretches were already sampled. Ichthyofauna was sampled using electrofishing. Multivariate statistical analyses will be conducted to evaluate species abundance at each site considering environmental variables (stream width, depth, flow, and bottom type, pH, conductivity, dissolved oxygen and water temperature), and spatial variables (geographic and longitudinal position, isolation degree, channel order, and preservation status of riparian vegetation). The present project will be developed with collaboration of Dr Robert Holt and his colleagues at University of Florida. (AU)