Shell characteristics of land snail Eobania vermiculata (Müller, 1774) (Helicidae) from Croatia

摘要

The land snail genus Eobania P. Hesse, 1913 in Croatia consists of four taxa: Eobania vermiculata vermiculata (O.F. Müller, 1774), E. v. pelagosana (Westerlund, 1894), E. v. figarole (Rensch, 1928) and E. v. kamenensis Berberovi?, 1963. Only E. v. vermiculata and E. v. pelagosana have been included in this study. The mean shell diameters (D) of the 13 samples ranged from 19.99 mm (sample from the island of Su?ac) to 31.78 mm (?ibenik, seaside) and the mean shell height (H) from 17.31 mm (Su?ac) to 25.66 mm (Island of ?olta). Shell morphology confirms that all island populations are smaller with examples of nanism on outside islands of Palagru?a and Su?ac. However, molecular analysis (16S rDNA and COI sequence data) showed no significant differences between the South Adriatic population from the mainland and islands, thus providing no molecular evidence for classification of a single E. vermiculata species into separate subspecies within the investigated area. The observed differences might possibly be attributed to ecological influences. The population with the largest average shell size was approximately 1.5x larger than the population with the smallest average size.