Molecular phylogenetic analysis of monogenean COI sequences using the Maximum Likelihood method. Bootstraps percentages (1000 replicates) are indicated next to the branches when higher than 70. There were a total of 389 positions in the final dataset. The Neighbour-Joining tree had a similar topology and is not represented. All specimens of Pseudaxine trachuri, whether with no vagina or with “multiple vaginae”, and whether from the type-host Trachurus trachurus or from Boops boops, were grouped into a single monophylum and showed little variation (<2%).