Comparison of the Spreading History of Two Introduced Cepaea Species (Gastropoda, Helicidae) in Ukraine with Remarks on Their Phenotypic Variability

Abstract

Trends of the current dispersal of Cepaea nemoralis and C. hortensis in Ukraine are analysed, which are closely related to the activities of several garden centres, which export a part of the sold seedlings of ornamental and garden plants from other European countries. Using Lviv and its environs as an example, we compared the qualitative and quantitative phenotypic composition of C. nemoralis at sites where both Cepaea species or only C. nemoralis were recently introduced. On average, the former were characterised by a greater phenotypic diversity of C. nemoralis, which may be due to a greater number of founding individuals of such colonies. At the sites of the second group, hereditary traits (brown ground colour, shell with three lower bands) or phenotypes (yellow unbanded), which are less common in the study area, were more often absent. Also, a clearly pronounced predominance of any one variant of the shell colouration was more often noted there, most often pink unbanded or yellow mid-banded.