Genetic variation in non-indigenous populations of the land snails Harmozica ravergiensis and Brephulopsis cylindrica (Gastropoda: Stylommatophora) in the south of the Central Russian Upland (Eastern Europe).
The Caucasian snail Harmozica ravergiensis Férussac, 1835 (Gastropoda, Stylommatophora, Hygromiidae) and the Crimean snail Brephulopsis cylindrica Menke, 1828 (Gastropoda, Stylommatophora, Enidae) have been spreading across the northern borders of their ranges in recent years. Here I present a study of the variability of ISSR loci in the populations of H. ravergiensis and B. cylindrica outside their natural range, in the south of the Central Russian Upland (Belgorod Region, Russia). A comparison is made with populations of these snail species in their native area (respectively, the Caucasus and Crimea). Genetic polymorphism is generally at the same level in alien and natural populations of the species. However, in some geographically isolated alien populations, the variability indices are lower than in the native area. The level of genetic differentiation between geographically distant populations indicates different sources of invasion. A high level of genetic differentiation was also detected between native populations. No isolation by distance was found for the Belgorod populations of H. ravergiensis (Mantel test, R2=0.065; P = 0.110). The exchange of migrants between these local populations is probably occurring anthropogenically.