Abstract
D.Phil. (Zoology)
Fish parasites may cause disease and lead to commercial losses. In order to construct practical management systems to mitigate or manage potential adverse effects, information on basic biological variables is required. Compared to the number of internationally published papers on the subject, little is known about the monogenean parasite fauna of South African fishes. Monogeneans are largely ectoparasitic, thin, flattened, host- and site specific parasites with a simple life cycle involving a single host (often a fish). They range in size between 0.3 mm and 20 mm and are mostly bilaterally symmetrical with the body subdivided into a number of regions. Attachment organs are a necessary feature both anteriorly and posteriorly, with the morphology of the prominent posterior attachment organ (opisthaptor) highly variable between genera. It may contain suckers, clamps or large hooks (anchors) as well as marginal hooks. In some genera anchors (one to two pairs) are associated with spikes or accessory sclerites and are supported by a connecting bar. All these structures, together with the sclerotized male copulatory organ, are of taxonomic significance....