Prevalence of Internal Nematode Parasites of Nile Tilapia (Oreochromis niloticus) Fish Species caught from Southwestern Part of Lake Tana, Central Gondar, Ethiopia

Background: Nile Tilapia a freshwater cichlid that is indigenous to the Nile basin and one of the world’s most important food fishes. Owing to its hardy nature and its wide range of trophic and ecological adaptations and the second most i mportant cultured species. Even though, it is susceptible to the parasite. Methods: A cross-sectional study was conducted from December 2017 to April 2018 to determine the prevalence of internal nematode parasites of Nile Tilapia (Oreochromis niloticus) fish in a southwestern part of Lake Tana, Central Gondar, Ethiopia. The study was performed on a total of 384 Oreochromis niloticus fish species which were purposively selected from local fisherman caught using different mesh sized gill nets. Results: The overall prevalence of internal nematode parasites in this study was 57.3% (220/384). The genera of nematode identified in the body of Oreochromis niloticus were Contracaecum the most prevalent 209 (54.4%), the second genus was Eustrongylides 7 (1.8%) and the list prevalent was Camallanus 4 (1%). The prevalence of nematode was slightly higher in female 196 (58.2%) than male 188 (56.4%) fishes. Similarly, the infection rate in adult and young and in larger and medium fish was higher. Conclusion: This higher prevalence observed was predominantly related to the distribution of piscivorous birds which are more abundant in an area, where there are high fishing activities and increase the number of discarded filleted wastes. Peoples who have developed the habit of consuming raw fish are at higher risk of becoming infected by the zoonotic nematode parasites. Therefore, awareness creation activities and control of fish parasites should be conducted in the study Lake.