Species Diversity, Settlement Routes, and Ecology of Freshwater Mollusks of Kolguev Island (Barents Sea, Russia)

It is established that the mollusk fauna of Kolguev Island (eastern part of the Barents Sea) is represented by 20–22 species of freshwater mollusks, of which 13 have been identified for the first time. The mollusk fauna of the island belongs to widespread Palearctic and Holarctic species. Canonical correspondence analysis (CCA) was used to study the relationship between environmental factors and the density of the freshwater mollusk. According to our data, the joint influence of the substrate type, the abundance of algae, and the chemical composition of water plays a significant role in the distribution of mollusks in the studied water bodies and watercourses. An analysis of gene sequences of 16S rRNA samples of bivalve species of the family Sphaeriidae showed that the specimens from Kolguev Island, Novaya Zemlya Archipelago, Vaygach Island, Yamal Peninsula, Gydan Peninsula, Europe, Siberia, the Far East, China, and North America have identical haplotypes or differ by one or two nucleotide substitutions. The molecular data indicate that the mollusk fauna of Kolguev Island is a result of recent migration after the digression of the ice. The dispersal of freshwater mollusks to the island could occur both through natural settlements through water systems and with waterfowl.