Parasites of the Invasive Snail Viviparus viviparus (L., 1758) in the Tura River (Tyumen oblast, Western Siberia)

To estimate the diversity of trematodes parasitizing the invasive mollusk Viviparus viviparus, the occurrence frequency of trematode larvae (cercariae and metacercariae) in the Tura River has been surveyed near the city of Tyumen in Western Siberia. In total, 53 snails with a shell height of 17–32 mm have been examined. Three trematode species are found: Cercaria nigrospora cercariae (3.77%), Neoacanthoparyphium echinatoides cercariae (5.56%), N. echinatoides metacercariae (58.5%, 47–279), and nonencysted Leucochloridiomorpha constantiae metacercariae (62.3%, 2–69).