Insights into the maintenance and consequences of asexual reproduction in rotifera

Despite much theoretical work, the evolution and maintenance of sexual reproduction in light of its apparent costs is not understood. Generally lacking are empirical data to test the proposed hypotheses. Rotifera, aquatic metazoans, are ideally suited to fill this gap as among these small, fast reproducing animals there are obligate sexual, facultative asexual and obligate asexual species. To this end the thesis focuses on the limits of asexual reproduction, primarily in the asexual bdelloid, but also in the facultative sexual monogonont rotifers. It is investigated how the ability to survive desiccation enables asexual bdelloids to survive despite missing sex. Furthermore, it was tested how monogononts versus bdelloids handle potential UVB-induced mutations, as mutations are thought to be difficult to handle for asexuals. At last it was monitored under different food- and temperature conditions when facultative sexual rotifers prefer to reproduce sexually instead of asexually.