The cases of assortative mating are known in varied species of Gastropoda, however it is unclear how widely distributed this reproductive strategy is across the class. The data concerning land snails (Stylommatophora) are especially contradictory. By using two model species of stylommatophoran mollusks, Brephulopsis cylindrica (Menke, 1828) and Xeropicta derbentina (Krynicki, 1836), we conducted a long-term observation of their copulatory behavior in Southern Ukraine. In X. derbentina, a clear pattern of the positive assortative mating with respect to body size was found, whereas assortative mating in relation to shell banding polymorphism was revealed in 2 cases out of 7. B. cylindrica snails copulate with any available mate partner, regardless of its size.
Spatial Variation of the Land Snail Brephulopsis cylindrica (Gastropoda, Pulmonata, Enidae): a Fractal Approach. Kramarenko, S. S., Dovgal, I. V. - Th e results of investigations of intrapopulation patterns in the land snail Brephulopsis cylindrica (Menke, 1828) variation are discussed in the article. Th e self-similar intrapopulational groups (demes) with sets of random (chaotic) and ranked (clinal) patterns of morphological characters were observed. It is argued that the self-similar elements lead to the formation of spatial variability patterns with distinct fractal nature. Thus the relative roles both of the random and the regular components can be detected for separate characters according to the degrees of nearness or remoteness of fractal dimension to 2.0.