1. Laboratory of Aquatic Ecology and Evolutionary Biology; K.U. Leuven; Leuven; Belgium
2. Freshwater Biology; Royal Belgian Institute of Natural Sciences; Brussels; Belgium
3. Research Institute for Nature and Forest; Brussels; Belgium
4. National Botanic Garden of Belgium; Meise; Belgium
5. Laboratory of Protistology & Aquatic Ecology; Ghent University; Ghent; Belgium