Theba pisana, common names the white garden snail, sand hill snail, white Italian snail, Mediterranean coastal snail, and simply just the Mediterranean snail, is an edible species of medium-sized, air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Helicidae, the typical snails. This species is native to the Mediterranean region, however, it has become an invasive species in many other countries worldwide. Theba pisana is a well-known agricultural pest in numerous parts of the world. The shell color varies from white to yellow-brown with light brown spiral markings.

Description

The shell background color is a creamy white. Different individuals may have shells with varying degrees of pale to dark brown markings. The markings, when present, may be in the form of uninterrupted spiral bands, spiral dotted lines, or small radial smudges. The shell can be found in various colour variants, but is basically yellow or white with dark color bands or spots and often a dark bluish grey apex. The shells of juveniles are sharply keeled, however the keel is not present on the final adult whorl. The aperture often has a lip that is light reddish on the inside, and the lip margin is only reflected at columellar side. The umbilicus is narrow and half covered by the reflected columellar margin. The apex has a characteristic size in the eastern Mediterranean when compared with other species, where there are no other Theba species. The umbilicus is also rarely seen in other species. Juveniles of Eobania vermiculata have a considerably larger apex. The width of the shell is 12–25 mm, but in Greece the adult shells are usually below 15 mm in width. The height of the shell is 9–20 mm. The visible soft parts are very light yellowish with dark colour bands running from the sides to the upper tentacles; the tentacles are very long. This snail is sometimes confused with Cernuella virgata, a species with a much smaller and less inflated shell.