Dwarf Wedgemussel

Alasmidonta heterodon

The dwarf wedgemussel is a small freshwater mussel. This species is unique in that it has two lateral teeth in the right valve and one in the left; other species have two lateral teeth in the left valve and one in the right. The mussel is found in small streams to medium-sized rivers with slow to moderate current and fine sediment, sand, or gravel substrates. It appears to have poor tolerance for suspended silt, and stream-side vegetation seems to be required. The only recorded Canadian location for the dwarf wedgemussel is the Petitcodiac River drainage of New Brunswick. A specimen was last collected there in 1960, at which time the species was classified as being common. It became extirpated in 1968, following construction of a causeway.