Isolation and Characterization of Fungal Strains from Tilapia (Oreochromis niloticus) and Machoiron (Chrysichthys nigrodigitatus) Fish in Taabo Lake, Kossou Lake, and Tagba Lagoon of Grand Lahou, Côte d’Ivoire

Abstract

This study aimed to isolate and characterize fungal strains contaminating freshwater fish (Tilapia and Machoiron) in three water bodies in Côte d'Ivoire: Lake Taabo, Lake Kossou, and the Tagba Lagoon in Grand-Lahou. A total of 120 samples were collected during four seasonal campaigns (dry and rainy seasons) and analyzed in the laboratory. Molds were isolated on acidified Potato Dextrose Agar (PDA) medium (pH 3.5) at 30°C and identified through macroscopic (color, texture) and microscopic (spore morphology, hyphae) observations. Contamination frequencies were calculated for each fungal genus. Among the 156 isolated strains, five dominant genera were identified: Aspergillus (57.69%), Rhizopus (25%), Fusarium (11.54%), Penicillium (3.85%), and Absidia (1.92%). Aspergillus was ubiquitous, while Rhizopus and Fusarium were more abundant during the rainy seasons. The analyzed fish showed high contamination rates: 75% for Aspergillus, 32.5% for Rhizopus, and 15% for Fusarium. These results confirm the presence of potentially toxigenic molds in fish, with associated risks of mycotoxin production (aflatoxins, ochratoxins). The contamination reflects environmental conditions and local practices. The study recommends establishing regulatory standards to limit consumer exposure and improve food safety.