Survey of protozoan parasites of selected freshwater fish species in Dinder National Park, Sudan

Abstract

Freshwater protozoan parasites constitute a persistent ecological and economic challenge in both wild fisheries and aquaculture systems. However, baseline epidemiological data from protected wetlands in Northeast Africa remain extremely limited. This study investigated protozoan parasites infecting selected wild freshwater fish species in Dinder National Park (DNP), Sudan, integrating morphological identification, epidemiological indices, and molecular characterization. Six protozoan genera were detected: Chilodonella, Trichodina, Trypanosoma, Myxobolus, Henneguya, and Microsporidia. Parasites exhibited marked organ specificity, with ciliates colonizing skin and gills, haemoflagellates infecting blood and spleen, and myxozoans/microsporidians targeting ovary, kidney, and liver tissues. Oreochromis niloticus displayed the highest parasite richness, particularly ovarian myxozoan infections. Epidemiological analysis revealed variable prevalence and mean intensity across host species, with statistically significant differences among infection sites (p<0.05). The findings establish foundational parasitological data for DNP and highlight potential implications for ecosystem health monitoring and aquaculture biosecurity in Sudan.