Ecological Risk Screening Summary - Pygmy Peaclam (Odhneripisidium moitessierianum) - Uncertain Risk

Species that are considered uncertain risk need a more in-depth assessment beyond the Ecological Risk Screening Summary to better define the species’ risk to U.S. environments.

Odhneripisidium moitessierianum, Pygmy Peaclam, is a small mollusk with a native range that spans from western Europe to western Russia and to some areas of the Middle East. O. moitessierianum is found in a variety of sediments as well as in the littoral zone of lakes and wide slow-moving rivers. It has been introduced to and become established in the United States, likely introduced via international shipping. While O. moitessierianum is established outside its native range, impacts of introductions remain unknown. The History of Invasiveness for O. moitessierianum is classified as Data Deficient due to a lack of evidence on either impacts of its introduction or lack of impacts, as well as no information found on its use in trade. The climate matching analysis for the contiguous United States indicated establishment concern for this species. Areas of highest match were found in the Great Lakes, Midwest, Mid Atlantic, New England, and in small areas of the Appalachian and Rocky Mountain ranges. The Certainty of Assessment for this ERSS is classified as Low due to limited information on the History of Invasiveness of O. moitessierianum. The Overall Risk Assessment Category for O. moitessierianum in the contiguous United States is Uncertain.