Population Parameters Of Distichodus Rostratus (Gunther, 1864) From The Hydrosystem Located Between The Hydroelectric Dams Of Kossou And Taabo (Bandama River; Côte d’Ivoire)

Abstract

Growth and mortality parameters, exploitation rates and annual recruitment patterns were estimated using FiSAT program from monthly length-frequency and weight samples of Distichodus rostratus captured from the hydrosystem located between the hydroelectric dams of Kossou and Taabo (Bandama River). Samples were collected from July 2004 to June 2005. The aim was to estimate growth parameters, mortality rates, exploitation rate and recruitment pattern of D. rostratus for sustainable management. The von Bertalanffy growth parameters asymptotic length L∞ (cm) and growth constant K (per year) were 69.30 and 0.27 respectively. Goodness of fit (Rn) was 0.27. The growth performance index (φ’) value was 3.11. Age at maturity was estimated at 2.87 years for males and 3.78 years for females. The maximum age estimated was 11.095 years. The annual rate of fishing mortality (F = 0.10) was low compared to the relatively high natural mortality (M = 0.60). The exploitation rate (E = 0.14) shows that the species was not over-exploited in the Bandama River.