Growth, Mortality, and Yield per Recruit of Synodontis schall (Bloch and Schneider, 1801) in Roseries Reservoir, Sudan
Résumé
This study assessed the population bio-parameters of shield-head catfish Synodontis schall (Bloch & Schneider, 1801) in the Roseries Reservoir (Sudan), using length-frequency data analyzed with FiSAT software. The von Bertalanffy growth parameters were determined as an asymptotic length (L∞) of 50.4 cm, and a growth curvature (K) of 0.17 yr.⁻¹. Mortality rates were calculated with total mortality (Z) at 0.63 yr.⁻¹, natural mortality (M) at 0.46 yr.⁻¹, and fishing mortality (F) at 0.17 yr.⁻¹, resulting in an exploitation rate (E) of 0.28 yr.⁻¹. The species exhibited continuous recruitment, with a maximum exploitation rate (Emax) of 0.409. Results indicate low fishing pressure on S. schall in the reservoir, which is a relatively low level of productivity. The relationship between total length and body weight also revealed a negative allometric growth pattern (b = 2.193) with a moderate correlation (r = 0.764).