Prevalence of ecto parasites associated with juvenile oreochromis niloticus and clarias gariepinus from selected fish farms in Wakiso District

Abstract

This study investigated the prevalence and diversity of ectoparasites affecting farmed juvenile Nile tilapia (Oreochromis niloticus) and African catfish (Clarias gariepinus) in four selected fish farms across Wakiso District, Uganda. The research aimed to address the gap in knowledge regarding parasite infestations in aquaculture systems, which pose significant threats to fish health, productivity, and economic sustainability. A cross-sectional design was employed, with 117 fish samples (78 tilapia and 39 catfish) collected from hatchery tanks and ponds of the four purposively selected fish farms. Parasitological examinations were conducted using skin scrapings and gill smears, followed by microscopic analysis to identify and quantify ectoparasites. The results revealed an overall parasite prevalence of 77.8%, with Nile tilapia exhibiting a significantly higher infestation rate (93.6%) compared to African catfish (46.2%). Five parasite species were identified, with Trichodina sp. being the most prevalent (74.4%), followed by Dactylogyrus sp. (30.8%), Gyrodactylus sp. (5.1%), Myxobolus sp. (4.3%), and Tetrahymena sp. (0.9%). Notably, Gyrodactylus sp. was exclusively found in catfish, suggesting species-specific susceptibility. The high prevalence of Trichodina sp. underscores its dominance in aquaculture systems, likely due to favorable environmental conditions such as poor water quality and high organic matter content. The findings emphasize the need for improved biosecurity measures, regular monitoring, and targeted parasite control strategies to mitigate economic losses and enhance fish health. Recommendations include farmer education on parasite control, optimized stocking densities, and further research on seasonal parasite dynamics and the impact of water quality on infestation rates. This study contributes valuable data to support sustainable aquaculture practices that will improve aquaculture production in Wakiso district and Uganda at large.