Studies on the life cycle of Asymphylodora tincae (Modeer, 1790) (Trematoda: Monorchiidae) in a small lake near Amsterdam. Part 1. The morphology of various stages.

Aspects of the life cycle of Asymphylodora tincae have been studied in a small lake near Amsterdam. Bithynia tentaculata, being the only snail species that was very numerous in the lake, was the first as well as the main second intermediate host; adult trematodes were found exclusively in the tench, Tinca tinca. A small part of the cercariae that penetrate into B. tentaculata was able to develop into progenetic specimens. A morphological description is given of the following stages of A. tincae: adult, egg, redia, cercariaeum, metacercaria and progenetic stage. The cercariaeum is identified as Cercariaeum paludinae impurae De Filippi, 1854. It is concluded that A. tincae is a species, capable of large variation regarding both morphological structure (e.g. body spination, size) and life cycle.