Pseudanodonta complanata

The depressed river mussel or compressed river mussel, Pseudanodonta complanata, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. The species name comes from the flattened shape of its shell. This species is found throughout northern Europe, but it is endangered throughout its range. While the survival of this species is thought to be threatened by pollution and the dredging of the slow-moving channels of water in which it lives, the species is also said to be 'easily overlooked' (it can be confused with Anodonta anatina or juvenile Anodonta cygnea) and thus it may be actually be more prevalent than current records show.