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Asian Clam

Corbicula fluminea

Regulatory Status

Asian Clams are not regulated by the FWC, and no permit is required to import this species or transport specimens within the state. Exportation of them from Florida into another state may require a permit depending on other state laws.

Description

The Asian Clam is a small species of freshwater mollusk, typically less than 50 mm (2 in) in length, characterized by a yellowish-brown shell with brown concentric rings. They have a lifespan ranging from 1 to 7 years, and reproduce annually.

The Asian Clam is hermaphroditic, allowing reproduction through both sexual and asexual means. Newly formed larvae disperse in water systems through passive currents-allowing rapid spread and establishment in downstream areas of rivers.

Their habitat consists of muddy benthic substrates in lakes, streams and rivers, where they burrow in shallow water areas and forage by filtering food particles from the water column.

 

Diet

The Asian clam is a filter-feeding bivalve. It filters microscopic organisms, such as plankton, from the water.

Native Range

They are native throughout Asia, North and South America, Europe and parts of Africa. They occurs primarily in streams south of 40 degrees latitude in the northern hemisphere.

Florida Distribution

Asian clams are distributed all throughout the state of Florida, with the largest populations established near Tallahassee, Pensacola and Gainesville. They are thought to have been brought into the United States by Asian Immigrants, and released into river systems as a food item. Additional release from bait buckets and the aquarium trade has contributed to the widespread distribution we see today. See where the species has been reported in Florida.

Potential Impacts

Asian Clams cause widespread economic problems through clogging the pipes of many Electric and Nuclear Power Plants. Water currents from streams, rivers, and reservoirs deposit the larvae within raw service pipes and condenser tubes of the plan. Here they attach themselves and grow to full size adults, resulting in reduced water flow and decreased efficiency of energy generation. This harmful impact is referred to as ‘biofouling’ and results in estimated costs of about $1 billion USD a year nationwide, presenting a large problem to the nation’s energy industry. Additionally, Asian Clams are known to be found in concentrations high as thousands of individuals per square meter, resulting in elimination of native freshwater mollusk populations through competition for food.