1. Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno 611 37, Czech Republic
2. Department of Ecology and Diseases of Zoo Animals, Game, Fish and Bees, University of Veterinary Sciences, Brno 612 42, Czech Republic
3. Department of Zoology, Fisheries, Hydrobiology and Apiculture, Mendel University in Brno 613 00, Czech Republic
4. Institute of Vertebrate Biology, Czech Academy of Sciences, Brno 603 65, Czech Republic