BLATNA, CZECHOSLOVAKIA

The life cycle of the tapeworm Khawia sinensis was studied on the basis of exa-mination of 280 stock carp (Cyprinus carpio- K 1-2 » and 9 671 water oligochae-tos of the families Tubificidae and Naididae from the pond Dra~skY Skalieany near Blatna from May 1987 to July 1988. The results showed the presence of the para-site in the pond throughout the year; the highest infestation of the carp was observed in late spring (May) and was followed by subsequent gradual departure particu-larly of gravid K. sinensis from the hosts at the end of June and at the beginning of July. Reinfection of the fish began in mid July. K. sinensis with eggs were found throughout the observation period. After dehelminthization the number of infested carp decreased but rose again within a month in consequence of reinfections. The intermediate host of K. sinensis in Czechoslovakia was ascertained for the first time under natural conditions. In the locality under study it was Tubifex tubifex (probably the exclusive intermediate host of K. sinensis there) which is not the dominant species in the pond compared with members of the genus Limnodrilus. K. sinensis larval stages can survive in intermediate hosts over winter when the pond is drained an