Cockle as Second Intermediate Host of Trematode Parasites: Consequences for Sediment Bioturbation and Nutrient Fluxes across the Benthic Interface

Trematode parasites are distributed worldwide and can severely impact host populations. However, their influence on ecosystem functioning through the alteration of engineering behaviours remains largely unexplored. This study focuses a common parasite system in marine coastal environments, i.e., trematode Himasthla elongata, infecting edible cockle Cerastoderma edule as second intermediate host. A laboratory experiment was conducted to investigate indirect effects metacercarial infection sediment bioturbation biogeochemical fluxes at water interface. Our results revealed that, despite high intensity, reworking bioirrigation rates, well nutrient fluxes, were not impacted. finding unexpected since previous studies showed that impairs physiological condition cockles induces mechanical obstruction feet, thus altering burrowing capacity. There several explanations for such contrasting results. Firstly, behavior could arise over longer time period following infection. Secondly, modulation by be more pronounced older specimens burying deeper. Thirdly, intensity deleterious impacts metacercariae strongly vary across species. Lastly, alters fitness an interaction with other biotic abiotic environmental stressors.