Identifying British freshwater snails: Freshwater or brackish?

Families: HYDROBIIDAE and ASSIMINEIDAE

These two families are taxonomically in the same superfamily, Rissoacea. For the purposes of this guide they are considered together at this point due to the superficial similarity of their shells. There are approximately 10 to 12 species occurring in north-west Europe, depending upon the authority used. All adult shells are within a height range of between 2.5 mm and 5.5 mm, which is rather forbidding to the inexperienced.

For our purposes we will start the identification by considering the natural habitat of the species within Britain and Ireland.

Please click on the appropriate habitat below.

Brackish-water habitats

Freshwater habitats