HISTORICAL REVIEW OF THE TAXONOMY AND BIOGEOGRAPHY OF FRESH-WATER FISHES IN SOUTH-AFRICA - THE PAST 50 YEARS

The history of systematic freshwater ichthyology in South Africa is tr aced from its origins to the present but focussing on the past 50 year s. In the 19th century freshwater fishes were described by European sc ientists and explorers. The first South African collections began arou nd the rum of the 20th century with that in the South African Museum b ecoming the dominant collection over the next 50 years through the inp ut and research of initially Dr John Gilchrist and later Dr Keppel Bar nard. A fundamental shift in locus from Cape Town to Grahamstown occur red in the 1950s when Rex Jubb began to work at the Department of Icht hyology at Rhodes University, and, from 1961 at the Albany Museum. Fre shwater fish taxonomy subsequently resumed at the J.L.B. Smith Institu te of Ichthyology, Grahamstown. The first half of the past 50 years wa s also marked by the contributions of nature conservation and colonial fishery agents. From 1970 a new generation of trained ichthyologists, locally and abroad, assumed responsibility and undertook mostly revis ions of species and genera. The impact of cladist philosophy is most e vident in the generic changes that have occurred during this latter ti me period. The alpha-taxonomy of the southern African freshwater fish fauna is about 90% complete. Modem focus is moving towards biophysiolo gical, biochemical, molecular and cytogenetic studies. Traditionally t he geographical derivation of southern African freshwater fishes was e xplained within the framework of a dispersalist paradigm. Alternative views arguing that there are two distinct historical faunas in souther n Africa, a temperate and a tropical fauna, have more recently been pr esented. The available evidence indicates that both these faunas have co-evolved largely in situ throughout the Tertiary. The patterns of sp ecies distributions that now exist are the product of a complex and dy namic process of drainage evolution.