U.S. Fish & Wildlife Service Dwarf Wedgemussel heterodon

When we think about the other species This reproduces sexually. The eggs Why bother? sharing this planet, it is easy to overlook are carried in the gills of the female and Human beings also are sensitive to metals, the very small creatures, and easier still if fertilized as sperm-laden water passes fungicides, herbicides, insecticides and those creatures live under the water's through the gills. Within the female's gills, fertilizers in the water. With the same surface. The dwarf wedgemussel is just the fertilized eggs develop into larvae sensitivities, dwarf wedgemussels serve as such an . Barely 1.5 inches long, this called glochidia, which the female releases a signal of a river or stream's health. Their tiny mollusk lives in freshwater streams into the water. A larva then attaches to a presence or absence indicates the health of and rivers. Although they once thrived in host fish's gills to continue growth. It a natural ecosystem. If the water is too about 70 different river systems on the appears that the glochidium only uses the silted or polluted for dwarf wedgemussels, Atlantic coast from New Brunswick, fish as a means of dispersal; after some it is not good for people, either. Lining Canada, to , dwarf weeks, the larva detaches itself from the stream banks with natural vegetation helps wedgemussels are now considered unharmed fish and drops to the river to buffer the flow of pollutants and control endangered. No longer found in Canada, bottom, where it may live as an adult for erosion, protecting both the water and the the species appears to be declining in 10 years. endangered dwarf wedgemussels living in and North Carolina. Small it. Ensuring the survival of dwarf populations remain in , while Changes that harm wedgemussels maintains healthy aquatic large populations have been found in New Degradation of dwarf wedgemussel habitat habitats for aquatic residents as well as the Hampshire, and additional populations is the greatest cause of this species' decline, rest of us. have been discovered in the Delaware and water pollution and construction of River watershed in , New impoundments are the primary threats to Northeast Region Jersey and . its survival. This mussel is sensitive to U.S. Fish and Wildlife Service elevated concentrations of potassium, zinc, 300 Westgate Center Drive Life on the bottom, and hitching a ride copper, cadmium and other elements. Hadley, MA 01035 Dwarf wedgemussels live on sand, firm Pesticides, chlorine, excessive nutrients and 413/253 8200 muddy sand, firm clay, and gravel bottoms silt carried by agricultural runoff also http://northeast.fws.gov in creeks and rivers of varying sizes with a present a threat to this species. Erosion slow to moderate current. To survive, they and siltation from land clearing as well as Federal Relay Service need a silt-free, stable streambed and well- grading and construction of bridges, roads for the deaf and hard-of-hearing oxygenated water free of pollutants. and other structures can bury and kill 1 800/877 8339 these bivalves. U.S. Fish and Wildlife Service Scientists believe another reason the http://www.fws.gov species is declining is that one of its hosts 1 800/344 WILD may be an anadromous fish species that has been blocked from some habitat areas December 2005 by dams and causeways. It is speculated that this is the reason dwarf wedgemussels disappeared from the Petticodiac River in Canada after a large causeway was built near the river's mouth. In addition, dam construction alters a river's current speed, oxygen levels, and amount and placement of silt, and may well result in unnatural water level fluctuations or drying out of the mussel habitat. Riprap and other artificial bank stabilization methods destroy the dwarf wedgemussels' substrate (bottom)

USFWS requirements.