Ladislavella tumrokensis: The first molecular evidence of a Nearctic clade of lymnaeid snails inhabiting Eurasia

Abstract

In this study, we provide the first molecular evidence for a possible connection between freshwater mollusc faunas across the Bering Strait via the Beringian Land Bridge using data inferred from gastropods of the family Lymnaeidae. The gastropods collected from geothermal springs in the Tumrok Mountains, West Kamchatka, Russia, share the nuclear internal transcribed spacer 2 (ITS2) and the cytochrome oxidase subunit I gene (COI) haplotypes, thus being as sister to those recorded for lymnaeid snails in the Stagnicola elodes group from Canada and the USA. Two lymnaeid species, Lymnaea (Orientogalba) tumrokensis Kruglov and Starobogatov, 1985 and Lymnaea (Polyrhytis) kurenkovi Kruglov and Starobogatov, 1989, were described from the Tumrok geothermal locality, but actually they are morphological variations of a single taxon of subspecies rank re-classified here as Ladislavella catascopium tumrokensis. This subspecies is the first discovered representative in the genus, which formed a dwarf race in a geothermal habitat. Our findings highlight the possible exchange between freshwater faunas in Beringia during the Pleistocene and an important role of geothermal ecosystems as possible cryptic refugia for freshwater hydrobionts.

Keywords:

• Beringian land bridge
• endemic species
• freshwater gastropods
• Ladislavella
• Lymnaeidae
• molecular taxonomy
• Tumrok hot springs

Acknowledgements

This work was supported by the President of Russia under grant no. MD-6465.2014.5 and МК-4855.2016.4, the Russian Federal Agency for Scientific Organizations under grant no. 0410-2014-0028, the Ural Branch of Russian Academy of Sciences under grants no. 15-12-5-3, the Russian Ministry of Education and Science under grant no. 6.1957.2014/К and the Russian Foundation for Basic Research under grant nos 14-04-98801, 14-04-01236 and 15-04-05638. We are grateful to Mr E.P. Dekin (Elisovo, Russia) and the team of the Krechet Tour Co. for their great help during field works. Special thanks to Yana G. Pchyolova, who collected the topotypes from Tumrok geothermal springs. We wish to thank museum curators: Dr Pavel V. Kiyashko and Lidiya L. Yarokhnovich (ZIN), Mag. Anita Eschner (NHMW) and Christine Zorn (ZMB) for their kind help during work with malacological collections.

Supplemental data for this article can be accessed here: http://dx.doi.org/10.1080/14772000.2016.1140244.

Disclosure statement

No potential conflict of interest was reported by the authors.