PHYLOGENETIC-RELATIONSHIPS OF TRICLADES (TURBELLARIA, TRICLADIDA, PALUDICOLA) OF LAKE BAIKAL DEDUCED FROM 18S RIBOSOMAL-RNA SEQUENCE DATA

Data on 5-terminal sequences of 18S rRNA genes were employed to recons truct the phylogeny of the Baikal triclades (Turbellaria, Tricladida, Paludicola). Out of 14 triclade genera of the Baikal fauna, nine gener a (16 species) were analyzed and found to fall into two statistically supported monophyletic groups, the first one including Bdellocephala s pecies and the other composed of species belonging to eight genera: Ar chicotylus, Armilla, Baikalobia, Hyperbulbina, Papilloplana, Protocoty lus, Rimacephalus, and Sorocelis. Literature data on the morphology an d karyology of species from these taxa were compared with molecular da ta.