Population parameters of African carp : Labeo parvus Boulenger, 1902 (Species Cyprinidae) in the Ouémé River in Bénin (West Africa).

Abstract

The population parameters (growth condition, mortality and recruitment patterns) of Labeo parvus from the Ouémé River (Bénin) are described from monthly data collected between April 2005 and March 2006. The von Bertalanffy growth function (VBGF) was fitted to the 12 consecutive month’s length-frequency data to obtain a VBGF with the following parameters: L∞ = 30.5 cm TL, K = 0.40 year-1. The growth performance index (Ø') was calculated as 2.57. The length-converted catch curve method gave the total mortality (Z) rate as 1.60 year-1, the natural mortality (M) was 0.96 year-1 while fishing mortality (F) was 0.64 year-1 and the exploitation rate (E) was 0.40. Labeo parvus recruited into the fishery from July to September corresponding to the period of the maximum water level and flow rate in the Ouémé River. The estimated potential longevity Tmax was 7.5 years.