The diversity of the Baikal lineage of Pallas, 1766: molecular and morphological evidence.

In this paper, molecular analyses of Baikal hydras from the ' group', based on COI and ITS1-5.8S-ITS2, and morphological analysis of their holotrichous isorhizas, were performed. Low genetic diversity and shared haplotypes were found between Pallas, 1766 and Swarczewsky, 1923 specimens, which is evidence of the mixing of these lineages. Genetic distances among all Baikal hydras (0.006) were less than the interspecific distances of other hydras. The size of hydras and proportions of their holotrichous isorhizas varied depending on microhabitat and environmental conditions. Our combined molecular and morphological approach proves that is synonymous with .