The Prevalence of Fish Parasites of Nile Tilapia (Oreochromis niloticus) in Selected Fish farms, Amhara Regional State

This study was conducted to assess the prevalence of fish parasites collected from selected small-scale fish farms in selected zones of Amhara regional state. Three small scale private fish farms and one government owned fish seed multiplication farm were considered in this study. Nile tilapia (Oreochromis niloticus) samples were collected from selected fish ponds in using seine nets and were transported live to the Bahirdar Fishery and Other Aquatic Life Research Center laboratory. Parasites were identified to the genera level with parasitological laboratory procedures and identification keys. Accordingly, eight genera of fish parasites belonging to trematodes (Clinostomum spp, Diplostomum spp., and Neascus), nematode (Contracaecum spp.), monogenea (Cichlidogyrus spp.), Acanthocephala spp., crustacean (Argulus spp.) and protozoan (Trichodina spp.) were identified. Among 198 sampled O. niloticus, 73.2% of the fish were infected by different external and internal parasites. Further studies of fish parasites in the region should be done the considering spatial and temporal or biotic and a biotic factor in disease causations in aquaculture