Pea Mussel
Sphaerium corneum
6mm

A tiny, fingernail-sized bivalve mollusc. When the two shell halves are clamped shut, almost spherical. Its shape, together with the pale brown colour, make it difficult to spot among gravel and sand on beds of ponds, streams and canals. Filter feeds and has two short, white siphons to assist this process. Muscular foot enables animal to adjust position. Common and widespread in lowland sites.