Stable isotope ratios of the studied food web components A all groups with means ± SD (empty symbols and error bars) B the isotopic niche overlap of the four invasive Ponto-Caspian mysid species illustrated by Stable Isotope Bayesian Ellipses corrected for small sample size (SEAc). The inner ellipses correspond to the 40%, the outer ones to the 95% credible intervals. CLA: Cladocera, COP: Copepoda, HA: Hemimysis anomala, KW: Katamysis warpachowskyi, LB: Limnomysis benedeni, PL: Paramysis lacustris.