First overview on trophic relationships of the invasive ctenophore Mnemiopsis leidyi in a Mediterranean coastal lagoon (Berre Lagoon, France): benthic–pelagic coupling evidenced by carbon and nitrogen stable isotope composition

The ctenophore Mnemiopsis leidyi, ranking among the 100 most damaging bioinvaders in world, is a major predator of zooplankton, known to alter biodiversity and functioning ecosystems which it has been introduced. This first survey on trophic relationships M. leidyi Mediterranean lagoon (Berre, South France) was performed through stable isotope analyses. Carbon nitrogen composition used (1) determine types prey ingested by this (2) influence individual size its composition, (3) make assumptions explore with native jellyfish Aurelia sp.. two gelatinous species mainly (79% 97% diet) planktonic (copepods, cirriped nauplii, gastropod larvae cladocerans), but also preyed upon benthic organisms (mainly harpacticoid copepods amphipod Monocorophium insidiosum) lower proportions (2.5% 21%). Size-related changes diet were evidenced an increase level consumption larger individuals. These probably play important underestimated role benthic–pelagic​ coupling coastal lagoons transferring organic matter pelagic food webs.