Length-Weight Relationship (LWR), Gonadosomatic Index (GSI) and Fecundity of Johnius borneensis (Bleeker, 1850) from Lower Agusan River basin, Butuan City, Philippines

Abstract

Length-weight relationship (LWR) and Reproductive phenology of Johnius borneensis (Bleeker, 1850) collected from Lower Agusan River was studied from the months of May 2017 to January 2018. Throughout the sampling period, a total of 304 specimens with 185 female and 119 males were examined and analyzed. The overall sex ratio is 2:1 with female preponderance. LWR of females showed positive allometric growth (b>3; p=0.0000) while male specimens followed negative allometric (b<3; p=0.000). Ovarian GSI showed to peak in reproduction during September. Fecundity-length and fecundity-weight shows low correlation coefficient in their relationship. J. borneensis had a short reproductive period with this it is highly recommended that fishing be strictly restricted during its spawning season (September) for this fish species to propagate their population in the area.