Evaluation of Nematode Parasitemia in Oreochromis niloticus from Lower New Calabar River, Port Harcourt, Niger Delta, Nigeria

A total of 100 samples of Oreochromis niloticus from the lower New Calabar River were examined to determine their levels of nematode parasitemia using standard parasitological techniques. An overall prevalence of (59%) was recorded comprising (5%) ectoparasites and (54%) endoparasites. Sex related parasitemia showed that males harboured more parasites (43%) compared to (16%) recovered in the females (P>0.05). Parasite specificity revealed three nematodes; Capillaria spp. (21%); Eustrongylide spp. (15%) and Goezia sigalasi (Ascarididae) (18%), and Lernaeocera branchialis; (5%) a crustacean were recovered from the samples. However, the study revealed a progressive increase in parasitemia as age of the fish host increased (P<0.05). The high parasitemia observed in this study was associated with the tidal effects of the water system which influences the organic load of the benthos directly and fish nutrition indirectly.