Length-weight relationship and condition factor for Prochilodus lineatus, an important commercial fish, in contrasting water-quality environments of the middle Tietê River basin, Southeast Brazil

Abstract This work was carried out in order to provide the length-weight relationship (LWR) and allometric condition factor (Ka), as well its correlation with limnological variables, for Prochilodus lineatus from middle Tietê River basin. Fish were collected using gill nets two rivers contrasting environmental conditions, totaling 46 specimens highly polluted River, 37 Peixe a relatively well-conserved tributary. Environmental measures obtained concomitantly fish capture. The results showed an isometric growth (b = 3.00) positive 3.23) River. mean value of Ka unexpectedly higher main river (Ka 2.63) when compared tributary 2.42), being statistically different each other. can be explained by much availability organic sediments river, resulting long-term eutrophication process. Nevertheless, significant correlations dissolved oxygen, both rivers, negative electric conductivity, nitrogen chlorophyll indicate effects water quality deterioration on factor. contributes expansion knowledge about P. lineatus, most important commercial basin, which is severely impacted unsustainable human actions.