Abstract

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During a recent investigation of parasites infecting fishes inhabiting different Canals at Behera governorate (Egypt), a total of 200 sharptooth catfish, Clarias gariepinus were examined for the presence of Myxosporidian infections. The clinical signs, postmortem lesions, histopathological and parasitological examinations were investigated. It was noted that the infected fish were off food and had respiratory manifestations, sluggish swimming, and congestion of the gills as well as the presence of cyst like structures on the gill filaments, in the cartilage of the accessory breathing organ. Parasitological examinations revealed great numbers of spores in the milky fluid inside the cysts, which identified the presence of plasmodia of Henneguya branchialis (Ashmawy et al., 1989) in the gills and accessory respiratory organ of the infected fish. Ultrastructure of H. branchialis was successfully identified by scanning electron microscopy (SEM). The prevalence of H. branchialis revealed that (20.5 %) of the examined fish were infected. It was also noted that the highest rate of infestation was found in spring and summer seasons and in female specimens more than males.

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