Theba pisana pisana (Müller, 1774)
Family: Helicidae.
Sizes vary from 12 to 25mm (width) 9 to 20mm (height)
Theba pisana, is a very common, edible snail, found around the Mediterranean coastal countries of Europe and adjacent Atlantic coasts.
It is known locally by the following names: The White Garden Snail, Sand Hill Snail, White Italian Snail and Mediterranean Snail. This species is native to the Mediterranean region.
The shell colours do differ, mainly to the exposure to the sunlight. The colour can vary from yellow-brown with light brown spiral markings to almost completely white.
It prefers sandy habitats and hot climates where it aestivates, (similar to hibernation) attached to a variety of wild plants and various man-made upright structures, like fence posts and walls. Numerous numbers of snails will be seen gathered close together, on just one plant. It will be seen regularly on beaches where vegetation sparsely grows. In colder regions the snails do not aestivate and will be seen more active all year round climbing on plants, when the conditions are dry. This species cannot tolerate serious winter frosts.
In the Mediterranean countries they have a biennial life cycle, breeding in the Autumn as well as the winter months. As they are a very invasive species, it has been known that they have been responsible for the decline in a number of other native species of snails, because of the competition of available food supplies. Theba pisana is a well-known pest to agricultural, in many countries where it is found in numerous numbers. Many types of plants and shrubs growth are also impacted, just by the vast numbers of snails feeding and aestivating on them.