Studies on microbial and helminths associated with Parachanna obscura in Eleyele Reservoir and Ajilete-Yewa River, SouthWestern, Nigeria

Abstract

This research aimed to increase our understanding of the microbial and parasitic composition of Parachanna obscura (African Snakehead) which is a commercially important freshwater fish species in Nigeria. The study was conducted in two locations, the Eleyele Reservoir in Oyo State, and the Ajilete-Yewa River in Ogun State, both in the southwestern, Nigeria. A total of 130 healthy P. obscura was collected from June to December, 2022 and examined for microbial and parasitic presence using standard methods. The prevalence of parasites was calculated, and the results were analyzed using one sample T test with p ≤ 0.05. Out of the 130 fishes examined, 94 (74.31%) were found to have parasites. The prevalence of parasites was higher in the Ajilete-Yewa River (75.9%) than in the Eleyele Reservoir (69.7%). Seven types of parasites were identified, including Procamallanus, Camallanus, P. africanus, C. metacercaria, Genarchopsis, Pallisentis and Trichodina. The female P. obscura had a higher parasite intensity of 50.36% than males (49.63%). Additionally, bacterial analysis conducted, reveal the presence of Bacillus spp, Escherichia coli (13.79 x 104CFU/g), Staphylococcus aureus (9.59 x 104CFU/g), Listeria monocytogenes (7.46 x 105CFU/g), and Salmonella spp(21.10 x 105CFU/g),. The findings highlight the need for public education on the potential dangers associated with consuming P. obscura and imply that the fish may contain variable degrees of parasitic and bacterial infections, some of which may be higher than the allowable amount.