Corbicula fluminea
Encyclopedia
Corbicula fluminea is a species
of freshwater
clam
, an aquatic
bivalve mollusk in the family Corbiculidae
.
This species is of originally mainly Asia
n origin and thus it is often commonly called Asian clam or Asiatic clam. In the aquarium and koi pond trade it is often called Golden Clam or Golden Freshwater Clam. In Southeast Asia it is known as the prosperity clam or good luck clam.
This species has been introduced into many parts of the world, including North America
and Europe
.
Right after reaching maturity these clams produce eggs, followed by sperm. Even later, they produce eggs and sperm simultaneously. They can self-fertilize, and release up to 2,000 juveniles per day, and more than 100,000 in a lifetime. Juveniles are only 1 mm long when discharged, and take one to four years to reach maturity. At this time they are about one centimeter long. Adults can reach a length of about 5 cm.
The outside of the shell is normally yellow-green with concentric rings. The color can flake, leaving white spots. The shells are lightly purple on the inside.
They feed primarily on phytoplankton
(algae
), which they filter from the sandy or muddy bottom of streams, lakes, or canals.
"An invasive clam, Corbicula fluminea, appeared at Lake Tahoe in 2002 in spotty numbers. But in the past two years, densities of the inch-long clam have jumped 100-fold. Waste from the clams, in turn, has helped trigger blooms of bright green algae". Researchers have recently found that since the early 1990s Lake Tahoe and other California and Nevada lakes have been warming at twice the rate of the surrounding atmosphere.http://europa.agu.org:8005/?view=article&uri=/journals/gl/gl0922/2009GL040846/2009GL040846.xml&t=gl,2009,Schneider. The USGS has concluded that C. fluminea is likely to continue to expand its North American range until it reaches its lower temperature tolerance.
Recently German researchers have determined that a "strong, positive effect of moderate winter warming on the clams' fitness is probably one reason for the recent invasion success of C. fluminea in the northern hemisphere."
The primary economic and social impact of the invasion of C. fluminea has been billions of dollars in costs associated with clogged water intake pipes, associated with power plants, among others. Ecologically, C. fluminea contributes to declines and replacement of highly vulnerable, already threatened native clams. http://www.issg.org/database/species/ecology.asp?si=537&fr=1&sts=sss.
, Thailand
, the Philippines
, China
, Taiwan
, Korea
, Japan
, but also in parts of Africa
.
Non-indigenous distribution of Corbicula fluminea include:
The ratio of width and height in C. fluminea is on average 1.1. In C. fluminalis it is smaller (0.97); still, there is much variation and considerable overlap in shape. Most easily, they can be distinguished by the amount of ribs on the shell; C. fluminea has 7 to 14 ribs per cm, C. fluminalis 13 to 28. This character is already clearly recognizable (albeit only by direct comparison) in very small (5 mm diameter) specimens. In addition, when viewed from the side (looking at the opening between the shells), C. fluminalis is rounder, almost heart-shaped, while C. fluminea has a slightly flatter shape like a teardrop with a notched broad end. Small specimens of C. fluminalis are almost spherical, while those of C. fluminea are decidedly flattened. All these differences except the rib number are a consequence of C. fluminalis having a markedly more swollen, pointed and protruding umbo (the oldest part of the shell valves, close to the ligament holding them together).
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
clam
Clam
The word "clam" can be applied to freshwater mussels, and other freshwater bivalves, as well as marine bivalves.In the United States, "clam" can be used in several different ways: one, as a general term covering all bivalve molluscs...
, an aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
bivalve mollusk in the family Corbiculidae
Corbiculidae
The Corbiculidae, common name "basket clams", are a family of aquatic bivalve molluscs in the order Veneroida.Clams in this family release many juveniles into the surrounding waters that have hatched inside the clams . Fertilization is internal...
.
This species is of originally mainly Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
n origin and thus it is often commonly called Asian clam or Asiatic clam. In the aquarium and koi pond trade it is often called Golden Clam or Golden Freshwater Clam. In Southeast Asia it is known as the prosperity clam or good luck clam.
This species has been introduced into many parts of the world, including North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
Right after reaching maturity these clams produce eggs, followed by sperm. Even later, they produce eggs and sperm simultaneously. They can self-fertilize, and release up to 2,000 juveniles per day, and more than 100,000 in a lifetime. Juveniles are only 1 mm long when discharged, and take one to four years to reach maturity. At this time they are about one centimeter long. Adults can reach a length of about 5 cm.
The outside of the shell is normally yellow-green with concentric rings. The color can flake, leaving white spots. The shells are lightly purple on the inside.
They feed primarily on phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
(algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
), which they filter from the sandy or muddy bottom of streams, lakes, or canals.
"An invasive clam, Corbicula fluminea, appeared at Lake Tahoe in 2002 in spotty numbers. But in the past two years, densities of the inch-long clam have jumped 100-fold. Waste from the clams, in turn, has helped trigger blooms of bright green algae". Researchers have recently found that since the early 1990s Lake Tahoe and other California and Nevada lakes have been warming at twice the rate of the surrounding atmosphere.http://europa.agu.org:8005/?view=article&uri=/journals/gl/gl0922/2009GL040846/2009GL040846.xml&t=gl,2009,Schneider. The USGS has concluded that C. fluminea is likely to continue to expand its North American range until it reaches its lower temperature tolerance.
Recently German researchers have determined that a "strong, positive effect of moderate winter warming on the clams' fitness is probably one reason for the recent invasion success of C. fluminea in the northern hemisphere."
The primary economic and social impact of the invasion of C. fluminea has been billions of dollars in costs associated with clogged water intake pipes, associated with power plants, among others. Ecologically, C. fluminea contributes to declines and replacement of highly vulnerable, already threatened native clams. http://www.issg.org/database/species/ecology.asp?si=537&fr=1&sts=sss.
As a native species
This clam originally occurs in RussiaRussia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, the Philippines
Philippines
The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, Korea
Korea
Korea ) is an East Asian geographic region that is currently divided into two separate sovereign states — North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by the People's Republic of China to the northwest, Russia to the northeast, and is separated from Japan to the...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, but also in parts of Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
.
As an invasive species
Corbicula fluminea was probably brought to North America at the latest in 1924, by Asian immigrants who used the clams as a food source. The clams are abundant in the Albemarle region of North Carolina, as well as other areas along the east coast.Non-indigenous distribution of Corbicula fluminea include:
- It was first found in the Rhine in the late 1980s and subsequently found its way into the DanubeDanubeThe Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....
through the Rhine-Main-Danube CanalRhine-Main-Danube CanalThe Rhine–Main–Danube Canal , located in Bavaria, Germany, connects the Main and the Danube rivers across the European Watershed, running from Bamberg via Nuremberg to Kelheim...
. It reached the ElbeElbeThe Elbe is one of the major rivers of Central Europe. It rises in the Krkonoše Mountains of the northwestern Czech Republic before traversing much of Bohemia , then Germany and flowing into the North Sea at Cuxhaven, 110 km northwest of Hamburg...
in 1998 at the latest. - Czech Republic - in Elbe in Bohemia since 2000 and it is spreading.
- It is now in rivers of PortugalPortugalPortugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
, like Minho RiverMinho RiverThe Minho or Miño is the longest river in Galicia, Spain, with an extension of 340 km.Both names come from Latin Minius...
. - Cuba
- Lake Placid, NY, USA
Taxonomy
There are in fact two species present in introduced populations, C. fluminea and Corbicula fluminalis. However, the two species are often mixed together. The names themselves are sometimes confused in the literature (e.g. by being called '"Corbicula fluminata"). Care needs to be taken in order to properly distinguish the two species.The ratio of width and height in C. fluminea is on average 1.1. In C. fluminalis it is smaller (0.97); still, there is much variation and considerable overlap in shape. Most easily, they can be distinguished by the amount of ribs on the shell; C. fluminea has 7 to 14 ribs per cm, C. fluminalis 13 to 28. This character is already clearly recognizable (albeit only by direct comparison) in very small (5 mm diameter) specimens. In addition, when viewed from the side (looking at the opening between the shells), C. fluminalis is rounder, almost heart-shaped, while C. fluminea has a slightly flatter shape like a teardrop with a notched broad end. Small specimens of C. fluminalis are almost spherical, while those of C. fluminea are decidedly flattened. All these differences except the rib number are a consequence of C. fluminalis having a markedly more swollen, pointed and protruding umbo (the oldest part of the shell valves, close to the ligament holding them together).
External links
- USGS (NAS)- Nonindigenous Aquatic Species
- "Aquatic Immigrants of the Northeast, No. 4: Asian Clam, Corbicula fluminea"
- Typical specimen of C. fluminea
- Typical specimen of C. fluminalis
- Anatomy of Corbicula fluminea
- Impact of Corbicula fluminea within US waterways
- GLANSIS Species FactSheet
- Species Profile- Asian Clam (Corbicula fluminea), National Invasive Species Information Center, United States National Agricultural LibraryUnited States National Agricultural LibraryThe United States National Agricultural Library is one of the world's largest agricultural research libraries, and serves as a National Library of the United States and as the library of the United States Department of Agriculture...
. Lists general information and resources for Asian Clam.