Sphaerium is a genus of very small freshwater clams, aquatic bivalve molluscs in the family Sphaeriidae, known as the fingernail clams. The small clams in this genus are unusual in that many of them, such as Sphaerium corneum, can climb around underwater on aquatic plants, using their long and strong foot.
See main article: List of Sphaerium species. The following species are included in the genus Sphaerium:[1]