Cercariae of trematodes from Bythinella austriaca [Frauenfeld, 1857] agg. [Gastropoda, Prosobranchia]

Snails of Bythinella austriaca agg. from streams in karstic and mountain regions of the Czech Republic (Moravia), Slovak Republic and Poland were examined for larval trematodes. A total of 549 (14.4%) snails were infected and harboured 12 species of cercariae belonging to the families Troglotrematidae, Nanophyetidae, Allocreadiidae, Lecithodendriidae, Microphallidae, and the superfamily Opisthorchioidea. No metacercariae were found in the snails, which indicates that other aquatic invertebrates are used as second intermediate hosts in these areas. It is assumed that Bythinella austriaca agg. plays an important role as the first intermediate host in the life-cycles of trematodes in the Carpathian region of Central Europe.