The application of fish species as bioindicator in mesohabitats of streams inserted into the upper Paraná River system, Brazil

Abstract

The objective of this study was to explore the presence of fish species as potential environmental quality indicators in tributaries belonging to the Paranapanema River basin, Upper Parana River System. We also sought to verify the possible occurrence of species associated with mesohabitats that indicate good or poor environmental quality, using the Indicator Value (IndVal) method for such verification. The sample units were distributed in 28 stretches of streams, and 3,103 individuals were collected, distributed in five orders and 33 species, so that Astyanax bockmanni was the most abundant species. Regarding the potential bioindicator, only a total of 13 species showed that they are possible indicators of at least one environmental variable (significance of p <0.05), so that Phalloceros harpagos and Geophagus brasiliensis were associated with high values of Salinity and Total Solids Dissolved, allowing us to observe, in a cautious way, that these species may be associated to environments with high amount of organic and inorganic particles suspended in water, indicating poor environmental quality.