Metacercarial production of Lymnaea viridis experimentally infected with Fasciola hepatica.

Three groups of Lymnaea viridis snails were infected with one, three or five Fasciola hepatica miracidia, and their metacercarial production was observed. In all groups cercarial shedding commenced in some snails as early as day 27 post-infection. The duration and pattern of cercarial shedding varied from snail to snail in each group. Snails infected with three or five miracidia produced more metacercariae than those infected with a single miracidium. The overall metacercarial production was influenced by the temperature at which the snails were kept during infection.