1. Faculty of Science, University of South Bohemia, Branišovská 31, CZ-37005 České Budějovice, Czech Republic
2. Biology Center of the Academy of Sciences of the Czech Republic, Institute of Parasitology, Branišovská 31, CZ-37005 České Budějovice, Czech Republic
3. Institute of Biological Sciences, National Research Council of Canada, 100 Sussex Dr., Ottawa, ON, Canada K1A 0R6