The painter's mussel is a species of aquatic bivalve mollusc. The shell is narrow and elongated, reaching up to 145 millimetres in length. The young mussels are yellow-olive in colour, turning brown-green as they get older. They burrow in the pond bed and move very slowly, using their foot as an anchor as they drag their large shells. They leave a distinctive trail. The two valves of the mussel fit exactly together, forming a firmly closed box of a convenient size and shape for storing artists' paints, which gives the mollusc its common name.
The painter's mussel lives in slow-flowing rivers and lakes and is common throughout Europe and Russia.
This mussel can be found at depths ranging from a few centimetres to several metres. It prefers a firm, muddy substrate and is less commonly found in sand, fine gravel and soft mud. It feeds mainly on organic particles in sediment, plants and phytoplankton filtered from the water.