Rotifers of the Kalahari Gemsbok National Park, South Africa

The Kalahari Gemsbok National Park in the Northern Cape Province, South Africa, is bounded by two dry river beds in which 39 artificial water sources have been provided for the use of the wild animals. The water in these sources varies from fresh to highly saline and an opportunity is thus provided to determine, not only which rotifer species are able to colonise such sources, but what their salinity tolerances are. The rotifer fauna, studied in summer and winter, is dominated by mixed populations of Brachionus calyciflorus, B. plicatilis and Hexarthra jenkinae, with only a few other monogononts and bdelloids. The most striking feature of the rotifer fauna in these troughs is the very low species diversity encountered.