PHYLOGENETIC ANALYSIS OF OPISTHADENA (DIGENEA, HEMIURIDAE)

Systematic study of the closely related hemiurid genera Mitrostoma, Ne opisthadena and Opisthadena revealed that Opisthadena cortesi is a jun ior synonym of Opisthadena dimidia and Opisthadena fujianensis and Opi sthadena marina are species inquirendae. Phylogenetic analysis of the 7 recognized species, based on 21 transformation series derived from c omparative morphologic characters, produced a single tree with a consi stency index of 0.735. The five species of the genus Opisthadena const itute a monophyletic clade and Neopisthadena habei is their sister gro up. Mitrostoma nototheniae is the sister group of the other 6 members of the clade. Geographic distribution suggests an ancient circum-Pacif ic distribution of the group. The association between kyphosids and th is group of hemiurids appeared with the ancestor of Neopisthadena and Opisthadena.