Abstract

• Labeo rohita, Piaractus brachypomus and Pangasius hypopthalmus are the most important fish species for Myanmar aquaculture and intensive investigation for protozoan parasites in these fishes are essential to develop methods for disease control. This study was conducted to examine the prevalence and infection intensity of protozoan parasites in cultured Labeo rohita, Piaractus brachypomus and Pangasius hypopthalmus collected from Lay Daung Kan fish farm. Thirty individuals from each species were collected monthly from January 2017 to December 2017. Gills, skin and internal organs were examined for protozoan infection. In total ten protozoan species were recorded including one species of Thelohanellus, two species of Myxobolus, one species of Zschokkella and one species of Trichodina in Labeo rohita. Two species of Myxobolus and one species of Trichodina were found in Piaractus brachypomus. In Pangasius hypopthalmus, one species of Myxobolus and one species of Trichodina were recorded. Among the recorded parasite species, the highest prevalence of infestation was found in Trichodina spp.