PARASITES OF SOUTH-AFRICAN FRESH-WATER FISH .7. NEMATODES OF SOME SCALED FISHES FROM THE HARTBEESPOORT-DAM, TRANSVAAL

The nematode parasites of 16 large-scaled yellowfish, Barbus marequens is, six silverfish, Barbus mattozi, six small-scaled yellowfish, Barbu s polylepis, 52 canary kurper, Chetia flaviventris, 11 carp, Cyprinus carpio, 45 Mozambique bream, Oreochromis mossambicus and a single-band ed bream, Tilapia sparrmani, caught in the Hartbeespoort Dam, Transvaa l, were collected, identified and counted. Contracaecum spp. larvae we re recovered from one O. mossambicus, 40 Chetia flaviventris, three Cy prinus carpio, one B. marequensis and five B. mattozi, Rhabdochona ess eniae from five B. marequensis, Rhabdochona spp. from one O. mossambic us and four Cyprinus carpio, and unidentified nematode larvae from two O. mossambicus, three Chetia flaviventris, two Cyprinus carpio and fr om the single T. sparrmani. Burdens in the infected fishes were genera lly small, and small-scaled yellowfish did not harbour any worms. Only Mozambique bream and canary kurper were caught at regular intervals, but even in these species no pattern of seasonal prevalence of the nem atodes was evident.