Abstract
This study focused on the diversity of fish fauna, its conservation status and its vulnerability in the Aghien freshwater lagoon (southeast of Côte d'Ivoire). For the fish data collection, two sampling approaches were used: experimental fishing and artisanal fishing. As a result, 80 species observed in this lagoon are distributed into 55 genera, 27 families and 10 orders. The best represented orders are the Perciformes, Siluriformes, Osteoglossiformes, Characiformes, Cyprinodontiformes and Pleuronectiformes. The Cichlidae, Mormyridae and Clupeidae represented the best diversified family. With an occurrence of 100%, the most frequent species are: Brycinus longipinnis, Chrysichthys nigrodigitatus, Pellonula leonensis, Schilbe intermedius and S. mandibularis. In the whole fish population, according to IUCN red list, four species where described as Near Threatened (Coptodon walteri, Marcusenius furcidens, Galeoides decadactylus and Cynoglossus senegalensis), four as Vulnerable (B. brevis, Rhexipanchax nimbaensis, Enteromius raimbaulti and Tilapia busumana) and one as Endangered species (Pseudotolithus senegalensis). These categories of species that have a conservation interest according to the IUCN Red List represent respectively 10.26% of the whole population. Fish population of the Aghien Lagoon are divided into seven classes ranging from “low” to “very high” vulnerability, regarding the vulnerability to stress due to fishing pressure.