Growth and exploitation parameters of ladyfish Elops lacerta Valenciennes, 1847 in the Ivorian's exclusive economic zone, Cí´te d'Ivoire

Growth parameters Von Bertalanffy model Population dynamics Exploitation rate West Africa.


January 13, 2022


West African ladyfish, Elops lacerta is a pelagic fish present in the coastal waters of West Africa from Mauritania to Angola. This study is conducted to provide data on the growth and exploitation parameters of E. lacerta important for the management and conservation of this species in the Ivorian's Exclusive Economic Zone (EEZ). These parameters were estimated by the indirect method using length frequency data collected in the Ivorian's EEZ during January 2019 to December 2020. Monthly length frequency data were analyzed by FiSAT II software. A total of 865 specimens were examined. The growth parameters from von Bertalanffy growth function (VBGF) estimations were L∞ = 60.38 cm fork length, K = 0.39 year−1, and t0 = 0.46 year. The estimated potential longevity (tmax) was 7.69 years. The exploitation parameters showed that the total mortality rate (Z), natural mortality rate (M) at 28.35°C and fishing mortality rate (F) were 1.57 year−1, 0.80 year−1 and 0.77 year−1, respectively. The exploitation rate (E = F/Z) was 0.49. This value is lower than the optimal exploitation value (E50), thus expressing a case of under-exploitation of the species in the Ivorian's EEZ. The size of first capture (Lc) below the size of first sexual maturity (FL50) and the optimal size of capture (Lopt) requires the implementation of an adequate mesh size management policy to allow fish to reproduce several times before being captured.