This study aimed at inventorying and analyzing the species of monogeneans parasitizing the gills of Chrysichthys nigrodigitatus Lacépède, 1803 (Siluriformes: Claroteidaein the reservoir of Bagré in Burkina Faso. It took place between June 2024 and March 2025 and examined a total of 120 specimens of these species of fish.
A qualitative study was carried out using a binocular magnifying glass and an optical microscope. Parasitological analysis identified a single genus divided into three species of monogeneans: Protoancylodiscoides spirovagina, Protoancylodiscoides valentini and Protoancylodiscoides sanagaensis. Among them, P. sanagaensis had the highest average intensity (AI=5.06), while P. valentini (AI=2.46) and P. spirovagina (AI=1.90) were observed at low average intensity. This high average intensity reflects a strong adaptation to its host. The study also showed a statistically significant difference (?² = 10.59; ddl = 2; p = 0.005) between the size classes of the fish and the infestation rate: large individuals were more strongly parasitized (P = 60%). In addition, the sex-specific analysis of C. nigrodigitatus shows a slightly higher prevalence of monogeneans in males than in females, regardless of the species considered: P. spirovagina (50% vs. 44%), P. valentini (40% vs. 37%) and P. sanagaensis (25% vs. 12%). P. sanagaensis was also favoured by the rainy season (P=28%), gill arches II and III are preferentially infested, these differences are statistically significant (the Kruskal-Wallis test (p= 0.021)).
International Journal of Fisheries and Aquatic Studies
