The presence of erratic cercariae of Fasciola hepatica in the lumina of the digestive gland of molluscs preying on Lymnaea truncatula.
D000818:Animals; D004064:Digestive System / Q000469:parasitology; D004463:Ecology; D005210:Fasciola hepatica; D008195:Lymnaea / Q000469:parasitology*