Malacofauna of Crimea as a possible source of introductions to other regions of Ukraine: land snails of non-Crimean origin

Abstract

Background. Due to global climate changes, a number of land mollusc species, previously known only from southern Ukraine or only from Crimea, are increasingly being recorded in different parts of the country. Apparently, not only species of the Crimean origin but also some other molluscs, native or alien to the Crimean Peninsula, could have been introduced from Crimea in different time periods. Therefore, the main purpose of this study was to generalise and give a critical analysis of data on the present distribution in Ukraine outside Crimea for 8 such species, whose primary source of dispersal could be, at least partially, the Crimean Peninsula. Materials and Methods. We used the results of our own long-term (from 1994 to 2023) research of the land mollusc fauna in different parts of Ukraine, examined collections of other researchers and amateurs, numerous stock materials of the State Museum of Natural History in Lviv, analysed a number of literature sources from the beginning of the 20th century to the present day, as well as reports from two citizen science databases (iNaturalist and UkrBIN). Results and Discussion. We have sequentially analysed the available data about the present distribution and chronology of discovery in different administrative regions of Ukraine outside Crimea for Cecilioides raddei, Phenacolimax annularis, Oxychilus deilus, Xeropicta derbentina, X. krynickii, Monacha cartusiana, Eobania vermiculata, as well as Helix lucorum with the shell colouration characteristic of the mountainous Crimea. It has been established that one or more species have now been reliably recorded in all parts and almost all administrative regions of Ukraine, with the exception of Sumy and Kirovohrad ones. Conclusion. The conducted analysis confirms the potential influence of Crimea on the formation of the present species composition of alien land molluscs not only in the south, but also in other parts of Ukraine. Most of the analyzed species are so far known only from those administrative regions that border the Black and Azov Seas. Two species, X. derbentina and M. cartusiana, are now rather widespread in Ukraine, but most of their known records were made no earlier than 1990s. The data systematized in this study can become the basis for monitoring the further spread of the species under study into different parts of Ukraine, which may become especially relevant in the post-war period.