The maximum-likelihood tree of genus Branchiobdella based on cytochrome c oxidase subunit I gene analysis was inferred with IQ-Tree (Nguyen et al., 2015). The numbers on the branches present ultrafast bootstrap values (≥0.7). Sequences were annotated with haplotype number according to Table S1. As presented in the legend, the symbols next to the haplotype names indicate the crayfish host. Asterisks (*) represent the new haplotypes obtained in this study. Groups recognized by mPTP analysis are displayed on the right side of the phylogram before the branchdiobdellidan species affiliation or name.