Sex Ratio and Length-Weight Relationship of Marcusenius furcidens (Pellegrin, 1920) from Solomougou Dam Lake (Côte d’Ivoire)

Abstract

Knowledge of growth parameters contributes to the conservation and sustainable management of fish stocks. This study aimed to characterise the sex ratio and length–weight relationship of Marcusenius furcidens by sex and sexual maturity in commercial catches from Solomougou Dam Lake. A total of 199 fish were recorded over eleven sampled months, from March to February, with no observations in September. The sample comprised 106 females, 66 males and 27 individuals of undetermined sex. Fish were measured (Lt in cm) and weighed (Pt in g), and the data were processed using Excel and STATISTICA 7.1. Among the 172 sexed fish, the male:female ratio was 1:1.61, with females accounting for 61.63% (two-sided exact binomial test, P = 0.002834). Monthly female predominance remained significant in June and August after Holm adjustment. The overall relationship was Pt = 0.018993 Ltᵇ, with b = 2.719271, R² = 0.8659 and a 95% confidence interval for b of 2.5689-2.8696. Negative allometry was observed overall (P = 0.000299) and in females (P = 0.001560). In males, b did not differ significantly from 3 (P = 0.121471). Slopes did not differ significantly between sexes (P = 0.488388). Among sexed fish at stages I-V, slopes did not differ significantly among stages (F = 1.840; df = 4, 158; P = 0.123700). The sampled catches showed female predominance and overall negative allometry. The equation provides a reference for converting length to weight within the observed range of 11-24 cm, subject to limitations associated with commercial catch sampling and fish of undetermined sex.