| The larvae inside the snail host produce several thousands of cercariae. |
| Only the tadpoles that were exposed to cercariae developed deformities. |
| Tadpoles in ponds with snails pick up trematode larvae, called cercariae. |
| The different geotactic behaviour of the two species of cercariae brings them into the ecological range of their different second intermediate hosts. |
| Through a complex process of asexual replication, each miracidium larva gives rise to dozens, or even hundreds, of cercariae. |
| Within the snail, the miracidium transforms into a sporocyst, which divides and eventually produces thousands of cercariae. |
