Zoological Studies

Vol. 53, 2014

Invasive lumbricid earthworms of Kamchatka (Oligochaeta)

Sergei V Shekhovtsov1*, Elena V Golovanova2 and Sergei E Peltek1

1Laboratory of Molecular Biotechnology, Institute of Cytology and Genetics SB RAS, Novosibirsk 630099, Russia
2Omsk State Pedagogical University, Naberezhnaya Tukhachevskogo 14, Omsk 644099, Russia

Background: Invasive earthworms often have huge ecological impact, especially when they colonize previously earthworm-free zones. Kamchatka is a remote and weakly populated region whose invertebrate fauna is insufficiently studied. We investigated earthworm diversity in several natural and anthropogenic habitats of Kamchatka by morphological analysis and barcoding using the mitochondrial cox1 gene.
We added four new species (Dendrobaena octaedra, Dendrobaena attemsi, Lumbricus rubellus, and Aporrectodea caliginosa) and one subspecies (Dendrodrilus rubidus subrubicundus) to the four earthworm species known previously from this region. Moreover, this is the first report of Dendrobaena attemsi in Asia. We found one mtDNA haplotype for each Eisenia fetida, Dendrodrilus rubidus subrubicundus, and Dendrodrilus rubidus tenuis; two significantly diverged haplotypes for Dendrobaena octaedra and A. caliginosa; and three for L. rubellus. In addition, cox1 sequences of Eisenia nordenskioldi nordenskioldi, the only earthworm species that could be of native origin, were identical to those of Eisenia nordenskioldi pallida from Khakassia and Tuva.
Conclusions: Molecular genetic analysis demonstrated that all earthworms found by us are of invasive origin, and for some of them, there were most probably several independent introduction events. This turned out to be true even for E. nordenskioldi, the species that was earlier considered to be native to this region. Our results suggest it might be possible that the whole earthworm fauna of Kamchatka is of invasive origin, which makes it a good model for studying the effects of earthworm invasions into previously earthworm-free regions.

Key words: Earthworms; Lumbricidae; Kamchatka; cox1.

*Correspondence: E-mail: shekhovtsov@bionet.nsc.ru