The study was conducted to determine the effects of ecto- and endo- parasites on morphometric parameters and proximal composition of African sharptooth catfish, C.gariepinus (Burchell, 1822) in Lake Hawassa, Ethiopia. Samples of C.gariepinus were collected from the selected sites of the lake using gill nets. Collected fish were transported to the Hawassa University Biology Laboratory. A total of 240 C.gariepinus (60 fish/month) were randomly collected from March to June, 2021.The morphometric data of each fish were recorded before dissection. The feeding intensity was recorded depending on stomach fullness. The fecundity was estimated by weighing the ovary of ripe fishes and counting the number of eggs per gram thereby the number of egg per ovary was calculated or extrapolated. The sample of muscle tissue was taken for biochemical analysis. The data obtained were analyzed by Statistical Package for Social Science software version 20. The feeding intensity in relation to the degree of infection revealed that the increased infection coincided with the poor feeders. The fecundity registered an inverse relationship with parasite infestation and the increased infection affected the fecundity. The Condition Factor in relation to infestation showed the poor condition and the length-weight relationship showed an isometric growth. The biochemical constituents showed that it was less in fish infected with more number of internal parasites. Detailed studies are required to fully understand the effects of ecto- and endo-parasites especially the effects of diverse groups of parasites on the bionomics and nutritional value of fish species.

Keywords: Clarias gariepinus; Condition factor; Length-weight; Proximate composition