Corbicula fluminea

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Geographic Range

The Asiatic clam is found throughout Asia, North and South America, Europe and parts of Africa. The clam occurs primarily in streams south of 40 degrees latitude in the northern hemisphere.

Habitat

The Asiatic clam prefers a lake or stream that has a a sandy or gravel substrate. However, they are also located underneath large boulders and in soft silts of deepwater lakes. The clam thrives better in fast flowing waters because the currents supply a constant source of the particulate food that the clam consumes.

  • Aquatic Biomes
  • lakes and ponds
  • rivers and streams

Physical Description

Reproduction

The Asiatic clam is hermaphroditic, with single genopores on each sides of the body. Reproduction and larval release occurs biannually in the spring and in the late summer. The clam is believed to practice self-fertilization, enabling rapid colony regeneration when colony populations are low.

Behavior

A typical settlement of the Asiatic clam occurs with a population density ranging from 100 to 200 clams per square meter. However, populations can grow as large as 3000 clams per square meter. There appears to be no competition for food among individuals within the species, however within high density populations, space competition is often important.

Food Habits

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

Economic Importance for Humans: Positive

The Asiatic clam is a major source of food and is harvested by humans throughout the world. The clam, when removed from its shell, also makes good fishbait.

Economic Importance for Humans: Negative

The clam creates a problem for power plants by blocking the ventalation systems and the water intake valves. Combined costs of outages, reductions in efficiency, capital investment in equipment, labor and chemical control, exceed 1 billion annually.

Conservation Status

Historically, wild populations of the Asiatic clam were exploited and harvested, to the extent that , locally, the clams once faced endangerment or extinction. Today, the clam thrives throughout the world.

Contributors

Robert Naumann (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

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Neotropical

living in the southern part of the New World. In other words, Central and South America.

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Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

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bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

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References

Britton, Joseph C. 1982. A Dissection Guide, Field and Labratory Manual for the Introduced Bivalve Corbicula fluminea. Malacological Review, Niwot, Colorado.

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Proceedings of the Second International Corbicula Symposium. 1986. American

Malacological Union, Hattiesburg, Mississippi.