Length-weight relationship of selected catfish species from the stretch between downstream Lloyds Barrage and upstream Kotri Barrage, Indus River, Sindh, Pakistan

Abstract

Catfishes are the crucial group in order Siluriformes occupy upper trophic levels due to their predatory feeding habits. This study examines the length-weight relationships of selected catfish species including Bagarius bagarius, Ompok bimaculatus, Heteropneustes fossilis, and Clupisoma garua collected from downstream Lloyds Barrage to upstream GM Barrage (Kotri Barrage) in the Indus River, Sindh, Pakistan. Fish samples were obtained over a year (July 2017 - June 2018) with the help of local fishermen and analyzed at the University of Sindh, Jamshoro. Measurements were taken using a digital balance, and regression analysis was performed using the cube law formula. The study found the regression parameters b and R² for B. bagarius (2.71 and 0.98), O. bimaculatus (2.82 and 0.94), H. fossilis (2.95 and 0.98), and C. garua (3.016 and 0.99). The "b" values suggested isometric growth for C. garua, while the other species indicated negative allometric growth. These values fall within the range (2.5-3.5), supporting the suitable growth of H. fossilis in the Indus River. This research provides vital baseline data for fisheries scientists, enhancing future studies and management strategies for these catfish species.