Parasites of South African freshwater fish. I. Some nematodes of the catfish [Clarias gariepinus (Burchell, 1822)] from the Hartbeespoort Dam.

A seasonal study of the parasites of fish in the Hartbeespoort Dam was undertaken in 1979. This paper deals with 4 nematode species recovered from catfish, namely, Paracamallanus cyathopharynx (Baylis, 1923), Procamallanus laeviconchus (Wedl, 1862), Contracaecum sp. and Skrjabinocara sp. Total numbers of parasites recovered are tabulated and their seasonal variation illustrated diagrammatically. Paracamallanus cyathopharynx was recovered from 23 out of 43 catfish examined and Procamallanus laeviconchus from 13, while Contracaecum sp. larvae were present in all the catfish. Skrjabinocara sp. was recovered from 1 catfish only, but it is not regarded as being parasitic in fish, as it was also recovered from 1 out of 4 cormorant examined. Paracamallanus cyathopharynx and Procamallanus laeviconchus are illustrated and the measurements of the Hartbeespoort Dam material compared with those given by various authors who recovered the same parasites from other fish species elsewhere in Africa.