In the comments to an earlier post about the snail Helix aspersa, a reader (Nemo Ramjet), who had photographed a live Eobania vermiculata, inquired about the differences between that species and H. aspersa (with apologies to non-Turkish speaking readers, I should point out that the subject comments and my answer were in Turkish). Both E. vermiculata and H. aspersa are edible species that have been introduced to places away from their original homelands. They are common in Turkey, where they are not native, in fields, gardens and ruins.
With a little practice, it is quite easy to tell the two species apart. There are many differences between their shells, but the most significant and the easily noticeable is the width of the body whorl, which is much larger relative to the width of the preceding whorl in H. aspersa than it is in E. vermiculata. As a result, the aperture of H. aspersa is also relatively wider than that of E. vermiculata.
The pattern on the shells of E. vermiculata almost always consists of brown bands with little variability, while the pattern and the colors on the shells of H. aspersa are more variable. Adult H. aspersa shells also tend to be larger than adult E. vermiculata shells, but size, in this case, is not always a reliable criterion to distinguish the 2 species from each other.
The variability of the patterns and colors of H. aspersa shells.