Asiatic clams (Corbicula fluminea) also know as the Asian clam was first discovered in the United States in the state of Washington in 1938 along the banks of the Columbia River and in 1964 in Florida. Currently, it is found in forty-six states including the District of Columbia and Puerto Rico. It is native to Asia, Afric, and Australia.
Asiatic clams are a filter feeder that removes particles from the water column. Found at the sediment surface or slightly buried. Population size can swing from year to year as they have the ability to reproduce rapidly and adapt to cold temperatures. The yellow and brown morphs are simultaneous hermaphrodites and brood their larvae in the inner demibranchs. They are also able to reproduce by self-fertilization at different ploidy levels. The lifespan is from one to seven years.
It is believed it entered the United States as a food item used by Chinese immigrants, but there is no direct evidence. It is also that it may have come in with the importation of the Giant Pacific oyster, which is also from Asia. It is unknown what the mechanism for dispersal within North America. What is known is it is mostly a biofouler of many electrical and nuclear power plants across the country. Water draws in from rivers, streams, and reservoirs for cooling purposes and so is the larvae. Inside a plant, the mussel can clog condenser tubes, raw service water pipes, and firefighting equipment. Further, this decreases the efficiency of the energy generated. The warm water from the power plants makes for a hospitable environment for stabilizing populations.
Asiatic clams have caused millions of dollars of damage to intake pipes in the power and water industries. Whether they are dead or alive, large numbers clog water intake pipes to an estimated cost of about a billion dollars a year removing them. Numerous nuclear reactors have had to be closed down temporarily in the US for removing from the cooling systems.
The Asiatic clam is consumed mainly by fish and crayfish. Some factors that might affect the population density and distribution include excessively high or low temperatures, salinity, drying, low pH, silt, hypoxia, pollution, bacterial, viral and parasitic infections, interspecific and intraspecific competition, predators and genetic changes. Predators include birds, raccoons, crayfish, and flatworms.