Patterns of spatio-temporal variation in land snails: a multi-scale approach

Abstract

Mechanisms which govern patterns of intra-specific vatiation in land snails were traced within areas of different size, using Brephulopsis cylindrica (Menke), Chondrula tridens (O. F. Müller), Xeropicta derbentina (Krynicki), X. krynickii (Krynicki), Cepaea vindobonensis (Férussac) and Helix albescens Rossmässler as examples. Morphometric shell variation, colour and banding pattern polymorphism as well as genetic polymorphism (allozymes and RAPD markers) were studied. The results and literature data were analysed in an attempt to link patterns to processes, with the following conclusions. Formation of patterns of intraspecific variation (initial processes of microevolution) takes different course at three different spatial scales. At micro-geographical scale the dominant role is played by eco-demographic characteristics of the species in the context of fluctuating environmental factors. At meso-geographical scale a special part is played by stochastic population-genetic processes. At macro-geographical scale more or less distinct clinal patterns are associated with basic macroclimatic indices, while the stochastic processes tend to lose importance. The basic factors of microevolutionary process which act at different spatial scales result from processes which progress over different lengths of time: micro-geographical variation patterns reflect processes which are in progress at the moment; meso-geographical variation is to a larger extent determined by processes which occurred in historic past; macro-geographical variation reflects processes which coincided with formation of the respective landscapes or climate zones.

Land Snail Sphyradium doliolum (Stylommatophora Orculidae), in Ukraine and Moldova: Distribution, Habitats, Variability and Origin

“…Therefore, we are dealing with an example of a large-scale geographic variability also complemented with a high level of a low-scale variability within regions. The latter could be a result of the microhabitat differences or some random factors (Kramarenko, 2016). Studied populations of S. doliolum are not significantly different in the number of the columellar teeth in the shell aperture (Pearson's chi-squared test: χ 2 = 14.016; df = 10; P = 0.172).…”

Intrapopulation variation in shell morphological traits and banding polymorphism of the land snail Cepaea vindobonensis (Gastropoda; Pulmonata; Helicidae)

“…However, earlier we noted a high level of conchiometric variation within continuous populations (metapopulations) of a land snail Brephulopsis cylindrica (Menke, 1828). Generally, the intrapopulation shell size and shape variation component is nearly 1/5 from the sum of the intra-and interpopulation variation (Kramarenko, 2016). Thereby the change in sampling strategy from "single population -single sample" to "single population -several samples" has been required.…”

“…The last detailed review of cases of the land snails intraspecific variation in shell shape and shell size with special consideration of its causes was given more than 30 years ago (Goodfriend, 1986). However, a large amount of actual material, which illustrates the formation of different patterns of the conchological variation among numerous species of land snails, has been accumulated over the last few years (see review Kramarenko, 2016).…”

Land snails <i>Brephulopsis cylindrica </i>and <i>Xeropicta derbentina </i>(Gastropoda: Stylommatophora): case study of invasive species distribution modelling

“…In their native ranges, both species inhabit open steppe areas where their populations are numerous. Both are typical xerophilous species having various adaptations to arid environments [Di Lellis et al, 2012;Troschinski et al, 2014;Dieterich et al, 2015;Kramarenko, 2016]. Studies of dispersal and locomotor activity of X. derbentina indicate its ability for successful geographical spread [Popov, Kramarenko, 2004;Aubry et al, 2006].…”