Snails (Gastropoda)

The species group can often be identified without enlarging aids
  • Common periwinkle. Littorina littorea. Photo: Aquatilis
  • Flat periwinkle. Littorina obtusata. Photo: Aquatilis
  •  Grey top shell. Gibbula cineraria. Photo: Aquatilis
  • Snails on a colony of Moss animals (Bryozoa). Photo: Mikael Olsson
  • A Nudibranch. (Nudibranchia)

Snails belongs to the group molluscs (Mollusca) and are found both in water and on land. Snails is one of the most species-rich groups with around 100 000 species.The aquatic species often have shells, but there are several exceptions, such as the nudibrachs (Nudibranchia). A shell consists basically of a viscera and a creep sole, called foot. In the front part of the foot there is a more or less clearly dedicated head with one (sometimes two) pairs of eyes bearing tentacles. The viscera can be pulled into a cone, which in turn is spiral shaped and covered by a large lime shell. In the front part, there is space for the snail to withdraw their entire body



Common periwinkle (Littorina littorea)

Rough periwinkle (Littorina saxatilis)

Flat periwinkle (Littorina fabalis and Littorina obtusata)