ECTO-PARASITES INFESTATION OF NILE TILAPIA (OREOCHROMIS NILOTICUS) IN CONCRETE PONDS IN TAMALE, GHANA

Abstract

The demand for concrete pond culture in the Northern Ghana is increasing. The safety and health of Nile tilapia produced in concrete ponds is of public concern. This study investigated the prevalence and mean intensities of ecto-parasites on the gills, skin and the fin of Nile tilapia (Oreochromis niloticus) in some concrete ponds in Tamale, Northern Region of Ghana. A total number of 240 randomly sampled fish specimens consisting fingerlings and adult fish of Nile tilapia were examined using microscope and hand-held lens from November, 2013 to April, 2014. Physico-chemical characteristics of the pond were suitable for culture. Mean temperature was 28.48 ℃ ± 2.31, mean dissolved oxygen was 4.32 mg/l ± 0.38, mean pH was 6.17 ± 0.23 and mean nitrate was 30.60 ppm ± 1.03. A total of 35 of the specimens examined were infested with ecto-parasites representing a prevalence of 15% during the study period. Out of 155 fingerlings examined, 14.8% were infested while 85 adult fish examined had 14.1% infested with ecto-parasites. The prevalence rate encountered was Ichthyophthirius multifilis (60%) ≥ Trichodina sp (23%) ≥ monogeneans (17%).The mean intensity of Trichodina sp ranged from 0 to 2.5. Monogeneans and Ichthyophthirius multifilis mean intensity ranged from 0 to 1.7. The low prevalence and intensities of ecto-parasites recorded indicated that with good water quality, ecto-parasites may not pose a threat to O. niloticus production in concrete pond.