Study on temporal variation of internal fish parasites in Lake Zwai, Ethiopia

Abstract

Lake Zwai is located in the rift valley of Ethiopia. Samples of Oreochromis niloticus were collected monthly 
between July (2010) to June (2011) using gill nets of various mesh sizes. The results indicated that the major 
internal parasites recorded belong to genus Clinistomum and Contracaecum including Cestodes larval. The 
prevalence of the parasite differs from season to season. Hence, the infestation was high during the month 
July to October (2010) for Contracaecum and Clinostomum where as the frequency of Cestodes larva was 
high in July to August (2010) and in between May and June (2011). On the average, the prevalence was high 
during July to October (2010) and in June (2011). In conclusion the parasite could bring zoonotic effect on 
humans even though there is a specific species. Therefore, further studies should be made for identification 
of these parasite and other common parasites which might cause production loss in the fishery sector.