Amino acid Bayesian phylogeny, based on 13 mitochondrial protein-coding genes depicting the evolutionary relationships amongst the focal taxa (highlighted with colour). Native European surface-dwelling species are shown with green shading, while invasive Ponto-Caspian species are in purple. Stars indicate taxa sequenced in this study. Green circles indicate nodes that received strong support in all analyses. Nodes with numbers received moderate to strong support. Numbers above nodes indicate statistical support (posterior probabilities—PP; ultrafast bootstrap—UFBS) for amino acid-based trees; below nodes for nucleotide-based trees. Nodes that are not annotated received weak/no support (PP < 0.5, UFBS < 50%). Inset photographs from top to bottom: G. fossarum, P. quadrispinosa, C. warpachowskyi and S. ambulans (D. Copilaș-Ciocianu).