Ecology of metazoan parasites of Clarias gariepinus (Osteichthyes: Clariidae) from the Nwanedi-Luphephe Dams of the Limpopo River System, South Africa

Abstract

A total of 7748 parasites, belonging to 17 metazoan species, was recorded from 45 specimens of Clarias gariepinus (Burchell, 1822) caught from the Nwanedi-Luphephe Dams, Limpopo River System, South Africa. All host specimens were parasitized by one or more metazoan parasite species. The parasite species included five monogeneans (Gyrodactylus rysavyi, Macrogyrodactylus clarii, Macrogyrodactylus congolensis, Quadriacanthus clariadis and Q. aegypticus), four digeneans (Diplostomum type 3, Tetracotyle sp. metacercaria, Acanthostomum sp. and Glossidium pedatum), two nematodes (Contracaecum larvae and Paracamallanus cyathopharynx), two cestodes (Proteocephalus glanduligerus and Tetracampos ciliotheca), two branchiurans (Chonopeltis inermis and Dolops ranarum), one copepod (Lamproglena clariae) and one unidentified leech. Eleven parasites were satellite species, with low prevalence (<33%) and mean abundance (<12.9 parasites per host). The nematode larvae (L3)of Contracaecum sp. were the dominant species, constituting 56% of the total metazoans (100% prevalence, mean abundance and mean intensity 96.3). Infra- and component community species richness and diversity were high. The dominance of host-specific parasite species in the sharptooth catfish confirms that its metazoan fauna has a considerable degree of specificity. This study indicates the importance of ecological determinants of richness in metazoan communities of the sharptooth catfish from dams in an oligotrophic state.