4-7mm. A conical but rounded aquatic snail, usually with just four swollen whorls and a relatively blunt tip. The aperture (mouth) is oval and has an operculum, though this is usually missing if viewing dead shells. The shell is usually light brown (old shells can be discoloured in sediment). Like its larger relative, Bithynia tentaculata, it has long tentacles that extend from the mouth when the animal is moving.

with a quality image

Images should show the side profile and the shell aperture. Also state the size.

Larger, well-vegetated water bodies such as lakes, canals and ditches. Rarely found in ponds.

All year.

Relatively common.

Uncommon or under-recorded.