Jossy Bekele,Daniel Hussien*
A cross sectional study was conducted from November 2013 to March 2014 in Lake Ziway to determine the prevalence of internal parasites and identify the most common genera infecting fish. A total of 384 randomly selected fish species comprising of 221 Oreochromis niloticus and 163 Clarias gariepinus were sampled. All the sampled fish were eviscerated in laboratory to investigate the internal parasites. Chi-square statistic and comparison of proportion were used to analyse the data. The overall prevalence of internal parasites of fish was 20.83% (80/384). The major internal parasite genera identified in the body of fish were Contracaecum (62.50%), Clinostomum (31.25%) and Eustrongylides (6.25%). The distribution of parasite genera was significantly affected by fish species (p=0.022). However, the difference between sexes was not seemed to be statistically significant (p=0.362) despite the prevalence was slightly higher in male (22.75%) than female (18.97%) fish. In conclusion, fishermen and other people who have developed the habit of consuming raw fish are at higher risk of becoming infected by the zoonotic parasites. Therefore, awareness creation activities and control of fish parasites should be conducted in the study Lake.