River Limpet - Ancylus fluviatilis

3-8mm. Ancylus fluviatilis is a species of very small, freshwater, air-breathing limpet, the shell has a conical, backwardly directed apex. Oval to round. It is fairly dull brown to black in colour and shows fine growth lines.

The Lake Limpet, A. lacustris, has a flatter profile and the apex of the shell is pointed to one side.

A bottom living species found in unpolluted running water of all kinds where it adheres to the sides of stones in moderate flows  It also lives on stones in the wave zone of lakes.

All year round.

Sensitive to pollution but is usually excluded from suitable habitat only by chronic pollution as it will normally recolonize lost territory after incidents.

Widespread and fairly frequent in Britain.

Fairly frequent in Leicestershire and Rutland.