The snail is a gastropod mollusc extended on a vast diversity of environments on the Earth. The most common species, typical of temperate climates –Helix aspersa-, has dark carapace, which allows it to absorb light and solar temperature, and lightly pigmented skin. On the other hand, another species of snail –Iberus gualtieranus alonensis–  typical of mountain areas -presents, in contrast to the previous one, white carapace and very pigmented skin, to protect itself from insolation.