1. Department of Hydrobiology, Institute of Environmental Biology , Adam Mickiewicz University , Umultowska 89, 61-614 , Poznań , Poland
2. Department of Botany, Institute of Biology , Jan Kochanowski University , Świętokrzyska 15, 25-420 , Kielce , Poland
3. Department of Botany and Zoology , Makaryk University , Kotlarska 2, 611 37, Brno, Czech Republic