Fig. 4

Haplotype networks for Diplostomum pseudospathaceum: (a) based on the novel cox1 sequences from metacercarial isolates sampled from nine fish species in the River Danube; (b) based on all currently published cox1 sequences from metacercarial isolates sampled from fishes in Europe. Numbers indicate the haplotype code number (see Table 2 and Additional file 2: Table S2 for details). Black dots represent inferred unsampled intermediate haplotypes and connective lines represent one mutational step. Pie chart size is proportional to the number of isolates sharing a haplotype; haplotype frequency is indicated by colourless semicircles. Hosts reported in this study (a) and host families (b) are colour-indicated. Abbreviations: C, Cyprinidae; L, Lotidae; P, Percidae