Growth and exploitation parameters of Oreochromis niloticus (Linné, 1758) in Guessabo Lake (Middlee - West: Côte d’Ivoire).

Abstract

Growth and exploitation parameters of Oreochromis niloticus were determined in Guessabo Lake. The study involved 515 individuals of Oreochromis niloticus collected monthly between August 2019 and July 2020. The values of the asymptotic length (L∞), growth coefficient (K) and growth performance index (Φ') are 21.57 cm; 0.93 yr-1 and 2.66, respectively. The values of total (Z) natural (M) and fishing (F) mortality obtained in this study for the species Oreochromis niloticus are 2.84 yr-1, 1.82 yr-1 and 1.02 yr-1 respectively. The operating ratio E is 0.36. The Z/K and M/K ratios are 3.05 and 1.95 respectively. The results show that natural mortality predominates over fishing mortality. Recruitment occurs twice a year with peaks in June and July.