Phylogeography of Eisenia nordenskioldi nordenskioldi (Lumbricidae, Oligochaeta) from the north of Asia

Eisenia nordenskioldi subsp. nordenskioldi is an earthworm species inhabiting a large part of Asia, from approximately the 40(A degrees) of north latitude to the shores of the Arctic Ocean. This taxon is known to have very high genetic diversity and contains several cryptic genetic lineages. In this study, we investigated phylogeography of E. n. nordenskioldi populations from the northernmost part of its range, from tundra and north taiga, using mitochondrial cox1 sequences. The studied populations were mostly represented by the 9th lineage of this subspecies. This lineage was estimated to have diverged about a million years ago, and many of its populations probably survived several glacial cycles in situ. Judging by phylogeographic patterns, the ancestral range of the 9th lineage was most probably located in southern Yakutia. From this area, it dispersed to the rest of the current distribution, where specific haplotype groups were detected in certain geographic regions: the Urals, the Kolyma river basin and the shore of the East Siberian Sea, the Taui bay, the Anadyr river valley, and Kamchatka. It is noteworthy that the Verkhoyansk ridge did not act as a barrier to earthworm dispersal, as populations from the Lena, the Yana, and the Indigirka basins were genetically similar but distinct from the populations of the Kolyma river basin.