Identifying British freshwater snails: Acroloxidae

Freshwater snails  » Shell shape » Shell cap shaped » Family: Acroloxidae
 

FAMILY: ACROLOXIDAE

GENUS: ACROLOXUS Beck, 1837
Acroloxus lacustris Linnaeus, 1758
Description: The apex of the shell of this freshwater limpet is inclined backwards and towards the left, although the animal itself is dextral. The shape is rather oblong, with a shell which is thin and glossy, but with a thick periostracum. It is much flatter and more compressed than Ancylus fluviatilis, but the shape is rather like Ferrissia wautieri, with which it could be confused except for the fact that in F. wautieri the apex is inclined to the right.
Size: Height: 1.2 - 2 mm. Length: 5 - 7 mm. Width: 3 - 3.5 mm.
Habitat: Frequently in quiet waters such as slow rivers, dykes, canals and lakes, where it is found on stems of water plants and the under surface of water lily leaves.

Acroloxus lacustris
Acroloxus lacustris
Linnaeus, 1758