Morphometric Indices and Enteroparasitic Infestation of Clarias gariepinus (Burchell, 1822) in a Tropical Reservoir

摘要

The study was carried out using 328 Clarias gariepinus specimens over a period of two years, from Oba reservoir (083'N to 0812'N and 0046'E to 00412'E) Ogbomoso, Oyo State, Nigeria. Standard methods were used to determine length-weight relationship, condition factor, and enteroparasitic infestation of the fish in the reservoir. Generally, Fish growth was positively allometric, while infested male and female fishes had negative allometric growth. The general well-being of the male fish was better than that of the female fish. Smaller sized fishes were better adapted to the ecological conditions of the reservoir than the bigger fishes. Parasites recovered were two Nematodes (Procamallanus laevionchus, Paracamallanus cyathopharynx), three Cestodes (Anomotaenia sp. Monobothrium sp., Polyonchobothrium clariae), and one Acanthocephalan (Neoechinorhynchus rutili). Sex ratio was 1.3:1 (male: female). Parasitic prevalence and intensity in the fish were sex and season dependent. The effect of enteroparasites in the life of infested C. gariepinus was found to probably be a major factor responsible for the low percentage of good fit to the line of regression (R~2) in females. Infestation also led to loss of weight in infested fishes and this affected morphometric values in which body weight was an index.