Aliens and Returnees: Review of Neobiotic Species of Freshwater Mollusks in Siberia from the Kazakhstan Steppe to the Arctic Tundra

Abstract

(1) This article reviews all available information on the species composition, current distribution, and origins of the neobiotic (non-indigenous and restoring the lost range) freshwater mollusks in Siberia. (2) An extensive literary search has been carried out, and virtually all existing publications of recent decades on the findings of freshwater mollusk species new to Siberia were taken into account. We examined extensive malacological collections of some of Russia’s and Kazakhstan’s scientific organizations. The core of the examined material is our own observations and collections made in various parts of Siberia and adjacent areas. (3) An annotated checklist of neobiotic species of mollusks reliably recorded in Siberia is presented, and probable mechanisms and “corridors” of infiltration of these species into the region are discussed. Most of the discovered snail species belong to a group popular among aquarists, and their source of introduction is obvious. Another large portion of species infiltrate into the region with the development of fish farming. A classification of species of neobiotic freshwater mollusks of Siberia was proposed and a forecast was made for changes in the Siberian freshwater malacofauna for the coming decades. (4) In our opinion, at present it is possible to accept the newest stage in the genesis of the freshwater malacofauna of Siberia, occurring in conditions specific to the Anthropocene.

Not a Silent Invasion: The Reaction of European Naturalists to the Spread of Zebra Mussel (Dreissena polymorpha) in the 19th—Early 20th Century

“…The existence of the Pleistocene refugia situated in Central and Eastern Europe cannot be ruled out either. In a series of recent studies, the application of molecular methods helped to identify such refugia for some species of pearl mussels (Unionidae), another family of freshwater Bivalvia [8,66,68,69].…”

“…Gray, 1840) is notoriously known as an overly aggressive and successful invader; since the 1800s, it has gained a foothold in many countries of Western and Central Europe as well as in North America [2][3][4]. The zebra mussel spread is ongoing [5], and it continues to conquer new regions, like North European Russia [6] and West Siberia [7,8]. In the late 20th century, another species of the genus, Dreissena bugensis (Andrusov, 1897), or the quagga mussel, repeated the success of its congeneric, being found today in many regions outside its native range [4,9].…”

“…In other words, the zebra mussel in Europe should not be treated (in many cases) as a "true" invader. The freshwater pearl mussels of the genus Unio Retzius, 1788 represent another example of this sort, actively restoring the lost part of their former range in Western Siberia [8]. The dispersal of D. polymorpha may be viewed as a part of a much broader process named 'The faunal Ponto-Caspianization' of European water systems [17].…”