The Strange Case of the Tetragenous Anodonta anatina

Unionoid freshwater mussels have a unique life cyclewith a form of parental care where the larvae are developed and kept inside the gills until release, followed by an obligate parasitic stage on fish. The size and location of the marsupium have been used as important phylogenetic characters in unionoids and in Anodontini its location was described exclusively on the outer demibranchs. Two rece…