Pisidium moitessierianum

Pisidium moitessierianum is a species of small freshwater clam.

This species is the smallest of the pea clams or Pisidium species, and the smallest of any freshwater bivalve, at 1.5 – 2.5 mm adult size.

The shell is long-oval and oblique wedge-shaped with prominent umbos which are slightly behind the midpoint.

The surface (periostracum) is silky, with regular concentric striae.

The species is native to Europe but has been introduced to northeastern North America.

Drawing of the right valve external view of Pisidium moitessierianum .
Drawing of the right valve lateral view of Pisidium moitessierianum .
Drawing of the right valve internal view of Pisidium moitessierianum .