A total of 109 samples of Clarias gariepinus (n=15) and Oreochromis mortimeri (n=94) were caught in Mashoko Dam between November 2014 and March 2015 and were examined for Contracaecum spp. larvae. The aim of the study was to determine the prevalence, mean intensity and mean abundance of Contracaecum spp. larvae in Clarias gariepinus and Oreochromis mortimeri from Mashoko Dam. 66.7% of C. gariepinus and 6.4% of O. mortimeri were infected with third-stage larvae of Contracaecum spp. in the body cavity. Mean intensity of infection by Contracaecum increased with increase in size (length) of both fish species (p>0.05). For both specimens there was no significant difference in mean intensity of infection between males and females (p>0.05). Contracaecum spp. larvae are important parasites of fish in Mashoko Dam.
Keywords: Contracaecum spp, Fish, Helminth, Mean intensity, Nematoda, Parasites