Journal of Basic and Applied Research International

Reservoir lakes in northern Côte d’Ivoire support important fisheries that contribute to local livelihoods and food supply. However, increasing fishing pressure and changes in fish assemblage structure highlight the need for reliable biological information to support sustainable management. Baseline data on the size structure, length–weight relationships, and condition of dominant fish species in Sologo Dam Lake are particularly important before rehabilitation activities are undertaken. This study assessed the size structure, length-weight relationships, and condition factors of the most abundant fish species in Sologo Dam Lake, northern Côte d’Ivoire, before rehabilitation. Fish were sampled monthly from artisanal fishers’ catches from January to December 2022, identified, measured for standard length, and weighed. Five dominant species were examined: Chrysichthys nigrodigitatus, Coptodon zillii, Oreochromis niloticus, Sarotherodon galilaeus, and Hemichromis bimaculatus. Size-frequency distributions were dominated by relatively small individuals, with modal classes of [8.5–10 cm[, [9.25–10.20 cm[, [10.75–13.70 cm[, [8–10.04 cm[, and [7.66–8.52 cm[, respectively. Length-weight analysis showed positive allometric growth in C. nigrodigitatus (b = 3.37) and H. bimaculatus (b = 3.18), whereas C. zillii (b = 2.23), O. niloticus (b = 2.74), and S. galilaeus (b = 2.34) exhibited negative allometric growth. Mean condition-factor values were 1.920 ± 0.431, 3.641 ± 0.813, 3.975 ± 0.768, 3.222 ± 0.865, and 3.186 ± 0.530, respectively. These findings characterise the pre-rehabilitation status of the principal fish species and provide baseline information for subsequent assessment of changes in the Sologo reservoir and for fisheries management and conservation planning. The results also establish a quantitative reference point for evaluating biological responses after planned rehabilitation activities.