engleski

Phylogenetic relationships among populations of the vineyard snail Cernuella virgata (da Costa, 1778)

Cernuella virgata (da Costa, 1778) (Mollusca: Hygromiidae), commonly known as the “vineyard snail” is endemic species in Mediterranean and Western Europe including the British Isles, but in the Eastern U.S.A. and Australia represents an introduced invasive species. The present work examines the genetic variability and phylogenetic relationships among the four populations of this land snail sampled along the East-Adriatic region of Croatia using mitochondrial markers (partial 16S rDNA and COI gene) in addition to traditional methods of shell’s shape analysis. All three molecular- phylogenetic approaches (Median Joining haplotype network analysis, Bayesian analysis as well as Maximum likelihood analysis) revealed two - three major sub- networks for both 16S rDNA and COI, with a clear distinction between south- Adriatic haplotypes (Pisak) and north-Adriatic haplotypes (Krk and Cres). The population from Karlobag was comprised of both north and south haplotypes thus representing a putative contact zone between these two groups. The morphometric analysis showed that individuals from Cres island population were statistically significantly wider and higher than individuals from Pisak population. Analysis of the SW/SH ratio and the relationship between shell width and shell height showed no differences in shell growth between the two examined populations, indicating equally shell growth and shape, which give the possibility that differences in size of individuals from those two populations could be influenced by biotic (physiological) or abiotic (environmental) factors. This study represents the first analysis of genetic variability and relatedness among native populations of C. virgata.

Cernuella virgata ; phylogeography ; 16S rDNA ; COI ; spatial genetic structure

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