Hydrobiological Studies on Alkaline and Acid Still Waters in the Western Cape Province

The invertebrate fauna of permanently alkaline and permanently acid small lakes in the western Cape Province is described. It is discussed from the point of view that the faunal associations present are related to the pH conditions. An important part of the fauna of permanently alkaline lakes consisted of species which appeared to be limited to alkaline conditions, whereas in acid, humic lakes there were few specialized, ‘acidobiontic’ species.