As a result of the present study Paramecium biaurelia was found in the ponds of the Botanical Garden in Krakow. It was the only species from the aurelia complex present in the ponds. The finding confirms previous observations (KOMALA 1997, 1998 a,b) indicating that Paramecium biaurelia is a species which invades marginal habitats more easily than do the other species of the complex.
E.Przybos, Department of Experimental Zoology, Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Slawkowska 17, 31-016 Krakow, Poland