Multiple infections of Helminths in the alimentary system of Clarias gariepinus (Burchell, 1822) in a tropical reservoir

摘要

The study was carried out in Erinle Reservoir accessed through Oore (Latitude 7° 58' 12" North; Longitude 4o 33' 36" East), in Osun State, Nigeria, between August 2011 and November 2013. A total of 103 live fishes purchased from local fishermen were examined. In the laboratory, morphometric parameters? were measured, the sexes determined and the fish species Clarias gariepinus were dissected to separate the alimentary system. Parasites recovered were identified and counted and the data were subjected to statistical analyses. The parasites recovered were Procamallanus laevionchus, Paracamallanus cyathopharynx (Nematodes.), Anomotaenia sp., Monobothrium sp., Polyonchobothrium clariae. (Cestodes) and Neoechinorynchus rutili (Acanthocephalan). Using a non parametric (NPar) (Kolmogorov-Smirnov; K-S) test, infection was significant at p = 0.05 within seasons, and female fishes were more infected than male. Monobothrium sp. had the highest range of infection (0 to 44) and intensity (18.5±2.65) while Anomotaenia sp. had the least (0 to 1) and (1.00±0.02) respectively. Six parasites were found in the intestine, while four were in the stomach. There was high prevalence in medium and large sized fish and a direct linear relationship exist between length and intensity. The body weight was significant in relation to infection at p = 0.05 (K-S test) and was also significant in sex. Multiple infections were common, which showed a positive correlation between most of the parasites except Anomotaenia sp. which showed negative correlation with P. clariae.