Corbicula fluminea

Corbicula fluminea is a species of freshwater clam, an aquatic bivalve mollusk belonging to the family Corbiculidae.

This species is originally from Asian origin, therefore it is often referred to as the Asian Clam or Asiatic Clam. Within the aquarium and koi pond trade it is frequently called the Golden Clam or Golden Freshwater Clam. Within southeast Asia its known as the Prosperity Clam or the Good Luck Clam.

It has been introduced into many parts of the world such as North America and Europe.

Directly after achieving maturity, these clams produce eggs, followed by sperm. Even later, they produce eggs and sperm at the same time. They can self fertilize, and release up to 2,000 juveniles per day and more than 100,000 during a lifetime. The juveniles are only 1 millimeter long when discharged and take one to four years to achieve maturity. At this time they are about 1 centimeter long. The adults can reach a length of about 5 centimeters.

The outside of the shell is usually greenish yellow with concentric rings. The color can flake leaving white splotches. The inside of the shell is light purple.

They feed mostly on phytoplankton which they filter from the muddy or sandy bottom of streams, canals, or lakes. According to the United States Geological Survey, this species is likely to continue to expand its range in North America until it reaches lower temperature tolerance.

The principle economic and social impact of the invasion of this species has been billions of dollars in costs in relation to the clogged water intake pipes, associated with power plants, among others. Ecologically, C. fluminea contributes to decreases and replacement of highly vulnerable, already threatened native clams.

It originally occurs in Russia, China, Philippines, Thailand, Taiwan, Korea, Japan, and also in parts of Africa.

This clam was most likely brought to North America at the latest in 1924, by Asian immigrants who used the clams as a source of food. The clams are common in the Ablemarle region of North Carolina, as well as other areas along the east coast. They are not native to but can be found in areas such as Rhine, the Czech Republic, Portugal, Ireland, Cuba, Venezuela, Lake Placid in New York, Allegheny River in Pennsylvania, and River Nore and Barrow in the Republic of Ireland.

Image Caption: Corbicula fluminea. Credit: USGS/Wikipedia