How do snails handle their need for water?
Most snails are probably more water sensitive than is usually believed. The humidity of the air affects the surface of their skin to a considerable extent. Every one has noticed how the snails ‘come out’ on a damp evening, especially after rain. The mucus of slugs and snails besides its use in facilitating locomotion, is a contrivance for checking evaporation by surrounding the exposed parts of the bodies with a viscid medium. The mucus has an affinity for water. Consequently when you try to rid your fingers of mucus do not get them wet. This will only make the mucus more fluid and sticky. To remove the mucus rub your hands together and the mucus will dry and peel off like glue. The pulmonate snail can carry an extra supply of water in the pallial cavity. This extra water supply permits them to be more active than operculates. Since the pulmonate can be active at lower humidity because of its extra water supply, they will return to activity before the operculates.
