Dispersal of trematode larvae: behaviour of free-swimming cercariae and parasite-manipulated snails

Main funder

Funder's project number: 318511

Funds granted by main funder (€)

  • 10 800,00

Funding program

Project timetable

Project start date: 05/02/2018

Project end date: 31/12/2019


Free-living larvae of trematodes, cercariae, shed by first intermediate hosts, mollusks, are so numerous that it seems they easily encounter their next host in the life cycle. However, small short-living cercariae are very poor searchers, and their target hosts, such as fish, are relatively rare and evasive. This makes host searching an extremely difficult task with the transmission success of cercariae much less than 1%. In addition, transmission success in trematodes is strongly limited by non-host predators that consume both cercarial larvae as well as parasites within their hosts. Low encounter rate and mortality due to host predation on different stages of trematodes’ life cycle, may create a “bottle-neck” that hamper transmission of these parasites.
Our question is, how trematode parasites could counterbalance this? We hypothesize that the transmission success may be facilitated either by behavioural adaptations of free-living stages, or/and by modifications of host behaviour, growth and morphology.
In our study, we are going to test if there are behavioural adaptations – either by cercariae or by infected molluscan hosts - to increase transmission between intermediate hosts (from snails to fish) in a widely distributed trematode parasite, eye fluke Diplostomum pseudospathaceum.

Principal Investigator

Primary responsible unit

Last updated on 2021-17-03 at 12:07