Novel integrated experimental and analytical approaches to unravel parasitic interactions by stable isotope analyses

Parasitic trophic interactions have been largely excluded in food web studies, but recent research has highlighted their integral role in affecting food web properties.

Previous efforts to unravel trophic interactions between parasites and their hosts have used stable isotope analysis of whole tissues (bulk SIA, 13C and 15N), but these studies show considerably higher variability in the isotopic differences between parasites and their resources than usually observed for free-living species.

This variability, combined with likely effects on the isotopic composition of infected hosts further confound trophic interactions within food webs.

PARAISO aims to make a significant contribution to our understanding of parasitic trophic interactions and their potential to affect the isotopic composition of infected hosts through an innovative integrated approach combining field sampling and laboratory feeding experiments with the simultaneous analysis of bulk SIA and compound-specific stable isotope analysis of amino acids (CSIA-AA).

This novel technique allows for the detection of changes in individual amino acids during trophic transfer and for comparison of source vs trophic amino acids to identify the trophic level of individual animals.

Combining field samplings, laboratory-based feeding experiments with four common coastal parasite-host systems, and the use of bulk SIA and CSIA-AA will allow for determination of isotopic changes caused by dietary shifts or parasitic infections in both hosts and parasites.

With this novel interdisciplinary approach using cutting-edge technologies, PARAISO will significantly advance our understanding of trophic transfer during parasite-host interactions.

Through successful implementation of this project, the gained skills and dissemination actions will considerably contribute to EU excellence in isotope ecology and ecological parasitology and place the applicant in a powerful position to continue her career.