Unio mancus

Unio mancus is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species can be found from northeast Spain throughout the Mediterranean zone, northeast Africa and in the Middle East. It is present in Austria, Bosnia and Herzegovina, Croatia, Cyprus, France, Greece, Italy, Lebanon, Montenegro, Slovenia, Spain, Switzerland, Syria and Turkey. Shells of Unio mancus usually reach a size of 55–65 millimetres (2.2–2.6 in), with a maximum of 10 centimetres (3.9 in). These freshwater mussels have a dark brown or yellowish-green periostracum. The shells are equivalve, inequilateral and oval-shaped, with a rounded anterior margin and a truncated posterior margin. The inner is iridescent white.