White-lipped Ramshorn - Anisus leucostoma

Description

Height 1.5 mm. Width: 5 to 7 mm. A small air-breathing freshwater snail. The shell is slightly glossy and rather thick, with close transverse striae, and is of a light horn colour. It has 6 to 6.5 rounded whorls which are evenly arranged in one plane, although the spire may be depressed and the lower surface rather concave. The periphery is generally only slightly shouldered above. There is sometimes a white rib around the inside of the mouth aperture, which is rounded, not oval.

Similar Species

The other small and tightly coiled species found in Leicestershire and Rutland is Anisus vortex. This has a strong angled keel around the edge whereas A. leocostoma is smoothly round.

Photo ID?
Habitat

It is commonly found in streams, ponds and ditches which dry out in summer, and in marshes.

When to see it

All year round.

UK Status

Common and widespread throughout Britain but less common further north.

Leicestershire & Rutland Map

UK Map