| Tadpoles in ponds with snails pick up trematode larvae, called cercariae. |
| Within this intermediate host, the parasite passes through a series of further stages known as sporocysts, rediae, and cercariae. |
| It was not only possible to generate mother sporocysts from miracidia in vitro, but also to obtain adult worms from cercariae through in vitro cultivation. |
| The different geotactic behaviour of the two species of cercariae brings them into the ecological range of their different second intermediate hosts. |
| The larvae inside the snail host produce several thousands of cercariae. |
| Through a complex process of asexual replication, each miracidium larva gives rise to dozens, or even hundreds, of cercariae. |
