Sex Ratio and Length-Weight Relationship of Marcusenius furcidens (Pellegrin, 1920) from Solomougou Dam Lake (Côte d’Ivoire)
Fokouo Kessia Irène Kouakou *
Laboratory for Environment, Climate, Health, Engineering and Sustainable Development, Peleforo GON COULIBALY University, BP 1328 Korhogo, Côte d’Ivoire.
Koffi Sylvanus Aubert Yao
Laboratory of Biological and Animal Sciences, UFR Science and Technology, Alassane Ouattara University, BP V18 Bouaké 01, Côte d’Ivoire.
Blé Yatanan Casimir
University of MAN, UFR Agronomic Forestry and Environmental Engineering, BP 20 Man, Côte d’Ivoire.
Ibrahim Imorou Toko
Research Unit in Aquaculture and Aquatic Ecotoxicology (URAEAq), Faculty of Agronomy, University of Parakou, BP 123 Parakou, Benin.
Konan N’Da
Laboratory of Animal Biology and Cytology, Nangui ABROGOUA University, 02 BP 801 Abidjan, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
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.
Keywords: Marcusenius furcidens, sex ratio, length-weight relationship, allometry, commercial catches, Solomougou