Length–weight relationship of eight native fish species from Paraguaçu River basin, Brazil

Abstract

This study reports the first record of Length-Weight Relationships (LWR) of eight endemic freshwater fish species from the Paraguaçu River basin, Northeast Brazil. Sampling was conducted in thirteen streams using electrofishing. Only Kalyptodoras bahiensis specimens from the middle section of Paraguaçu river were obtained from local fishermen. Fishes were fixed with 4% formalin before measurement, so some shrinking should be considered. Total weight (TW) was measured to the nearest 0.1 g and standard length (SL) to the nearest 0.1 cm. The LWR parameters were determined using the linear regression model: log TW = log a + b log SL, where ‘a’ is the intercept and ‘b’ is the slope of the linear regression. All LWRs were significant (p < .01) with r2 values ranging from 0.796 to 0.97. The allometric coefficient ‘b’ values ranged from 2.39 to 3.32. New maximum lengths are recorded for Geophagus diamantinensis and Copionodon lianae.