Free-living nematodes from rivers in the Kruger National Park

D.Phil. (Nematology)This was the first study on aquatic nematodes from the Kruger National Park. Samples were taken more or less randomly over a period of two years from the four main rivers in the park, viz. the Crocodile, Sabie, Olifants and Luvuvhu rivers. A total of 33 species representative of 24 genera were found. Dorylaimida seemed to be dominant in most of the sampling sites in the Sabie, Olifants and Luvuvhu Rivers, but there was no dominant group in the Crocodile River. Five new Dorylaimida species are described: Dorylaimus deaconi spec. nov., Laimydorus olifanti spec. nov., Laimydorus africanus spec. nov.; proleptonchus krugeri spec. nov. and Aporcelaimellus glandus spec. nov. Previously known dorylaim species which were redescribed in detail are Mesodorylaimus sp.cf paralitoralis Basson & Heyns, 1974; M. potus Heyns, 1963, M. aegypticus (Andrassy, 1958), Aquatides thornei (Schneider, 1937), Afractinolaimus zairensis (Baqri, Coomans & Van der Heiden, 1975) and Oxydirus gangeticus Siddiqi, 1966. Further dorylaim species recorded are Aporcelaimellus micropunctatus Botha & Heyns, 1990, Discolaimus monoplanus Heyns, 1963, D. major Thorne, 1939, Xiphinema italiae Meyl, 1953, Thornenema baldum (Thorne, 1939), Tyleptus striatus Heyns, 1963 and Dorylaimellus (Axodorylaimellus) caffrae (Kruger, 1965) . The following Tylenchida species were found: Hemicycliophora labiata Colbran, 1969, Helicotylenchus africanus (Micoletzky, 1916) and Scutellonema brachyurum (Steiner, 1939). Three Araeolaimida species were recorded, viz. Chronogaster africana Heyns & Coomans, 1980, Plectus cirratus Bastian, 1865 and Rhabdolaimus terrestris de Man, 1880. The latter species is redescribed in full collected and (de Man, 1979). Only one species of the Cromadorida viz. Achromadora ruricola 1880), Enoplida viz. Eutobrilus annetteae (Joubert & Heyns, Monhysterida viz. Monhystera somereni Allgen, 1952, were Detailed descriptions are given to incorporate additional morphological information obtained. Brief descriptions and new distribution records are also given for Mononchus truncatus Bastian, 1865, M. aquaticus Coetzee, 1968 and Mylonchulus minor (Cobb, 1893) of the Mononchida and Ironus longicaudatus de Man, 1884 and I. ignavus Bastian, 1865 of the Iro~idae.A diagnostic compendium for the Mesodorylaimus species of South Africa and a checklist of the free-living and plant parasitic nematode species from both terrestrial and aquatic habitats in the park are also included. Most of this work has already been published or submitted for publication in scientific journals and is presented in this thesis in the same format as required by the editors of the journals concerned