REVISION OF THE GENUS LYCODRILUS AND DESCRIPTION OF THE EVOLUTION OF LIMNODRILUS (OLIGOCHAETA, TUBIFICIDAE) SPECIES IN LAKE-BAIKAL - I - REVISION OF LYCODRILUS-DYBOWSKII GRUBE SPECIES AND TUBIPENIFER SEMERNOY GENUS

The genus Lycodrilus Grube, 1873; was considered endemic for Lake Baik al and until 1982 included five species characterized by simple setae located in pairs or singly. The Lycodrilidae family for this genus was setup in the Lumbricomorpha order (Chekanovskaya, 1962), but was clos ed (Snimshchikova, 1984, 1987) after revisions by Grabe (1982) and Bri nkurst (1984), who proved that two species of this genus belonged to t he Tubificidae family (Naidomorpha order). As a result of these revisi ons the genus Lycodrilus was left with only the species Lycodrilus dyb owskii Grube, 1873, Based on examination of the inner morphology and a nalysis of relevant literature, the genus Lycodrilus is abolished, the species L. dybowskii is again attributed to the genus Limnodrilus Cla parede, 1862. Four morphological variations of this species and one su bspecies Limnodrilus dybowskii haplochaetus ssp. n. are described. Tub ipenifer tendens Semernoy, 1982 is declared a junior synonym of L. dyb owskii. Tubipenifer nitens Semernoy, 1982 is attributed to the genus L imnodrilus in the rank of species.