Occurrence of a Sphaerium species (Bivalvia: Sphaeriidae) of Nearctic origin in European Arctic Russia (Vaigach Island) indicates an ancient exchange between freshwater faunas across the Arctic

Abstract

Although a recent series of studies has examined the phylogeography and diversity of Arctic invertebrates related to the glacial history on a pan-Arctic scale, large gaps remain in the knowledge on the origin, dispersal and biogeography of freshwater mollusks in the Russian Arctic. In samples from two lakes on Vaigach Island, Arctic European Russia, we found five specimens of an undescribed Sphaerium species (Bivalvia: Sphaeriidae), which is most closely related to Nearctic species (particularly Sphaerium rhomboideum), with the majority of known occurrences in the Great Lakes region of North America. This finding suggests a Nearctic rather than Palearctic origin of this lineage. Genetic evidence demonstrated the existence of freshwater refugia in the European Arctic during the last glacial maximum, and a Nearctic origin of the Vaigach lineage would suggest the existence of a phylogeographic element distinct from other bivalve molluscs of Northern and Alpine Europe origin inhabiting the European Arctic.