Swan Mussel
Anodonta cygnea
Shell length up to 12cm

A large and impressive bivalve mollusc which is found in slow-flowing rivers, canals and lakes. In sites where the animal is common, empty shells are often washed up on the shoreline and live mussels can sometimes be seen side by side in clear, shallow water from bridges and other overlooks. Lives part-buried in silt and filter-feeds organic particles and breathes by passing large quantities of water through its body via siphon. Can alter its position in the substrate using a large, powerful foot. If disturbed, muscles clamp the two shell halves tight. Widespread but local in England, Wales and Ireland; scarce in Scotland.