In this article we will discuss about the structure of Polystomum with the help of a diagram.
1. They are endoparasites in the urinary bladder of frogs, toads and turtles.
2. The body is dorsoventrally flattened and leaf-like.
3. They are acoelomate, triploblastic un-segmented and monogenetic trematodes.
4. Anterior end without or with a weak sucker J. Posterior end has a disc like oplsthaptor with 6 suckers arranged in a circle. The suckers have 2-3 hooks.
5. They are hermaphrodite and life history is completed in one host. Intestine is divided and eyes are absent.
6. Infection takes place through tadpole of the host.
7. Eggs are released in urinary bladder of host from where they escape to outside with urine.