| mallard ducklings (anas platyrhynchos) experimentally infected with echinostoma trivolvis (digenea). | of 8, day-old mallard ducklings, each fed 50 encysted metacercariae of echinostoma trivolvis, 4 (50%) were infected 15-31 days postinfection (pi) with a total of 10 (2.5%) worms. the worms were attached loosely to the mucosa of the lower ileum and rectum-cloaca, and some were ovigerous by day 15 pi. ducklings, 4-14 days old when fed encysted metacercariae, became infected with e. trivolvis adults, but ducks 150 days old were refractory to infection. compared to our previous studies on experiment ... | 1990 | 2380872 |