PHYLOGENETIC RELATIONS BETWEEN SPECIES OF THE GENUS COTYLURUS AND ITSPOSITION IN THE SYSTEM OF THE TREMATODE FAMILY STRIGEIDAE

Cladistic analysis of phylogenetic relations between species of the ge nus Cotylurus was carried out. The obtained data show that the genus i s homogenous and monophyletic and serve as a basis for unification of the genera Cotylurus and Cotylurostrigea as the species assigned to th e latter do not form a monophyletic branch. The same analysis of separ ation phylogenetic relations between the genera of the family Strigeid ae has confirmed the validity of separation of the genus Pseudapatemon into a distinct subfamily. The other genera form two distinct monophy letic groups differing in the structure of copulatory organ. It seems to be expedient to accord the above groups the rank of subfamilies: Co tylurinae (the genera Cotylurus and Ichthyocotylurus) and Strigeinae ( all the other genera excluding Pseudapatemon).