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This species is of originally mainly Asian 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.
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. According to the United States Geological Survey, C. fluminea is likely to continue to expand its North American range until it reaches its lower temperature tolerance.
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. .
Distribution[edit source | edit]
As a native species[edit source | edit]
As an invasive species[edit source | edit]
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 Danube through the Rhine-Main-Danube Canal. It reached the Elbe in 1998 at the latest.
- Czech Republic - in Elbe in Bohemia since 2000 and it is spreading.
- It is now in rivers of Portugal, like Minho River. First recorded in Ireland in 2010. 
- Lake Placid, NY, USA
- Allegheny River, Pittsburgh, PA
- River Nore & Barrow, Republic of Ireland. First recorded in April 2010.
Taxonomy[edit source | edit]
There are in fact two species present in introduced populations, C. fluminea and C. 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).
See also[edit source | edit]
References[edit source | edit]
- USGS (2001): Nonindigenous species information bulletin: Asian clam, Corbicula fluminea (Müller, 1774) (Mollusca: Corbiculidae). PDF fulltext
- Jueg, U. & Zettler, M.L. (2004): Die Molluskenfauna der Elbe in Mecklenburg-Vorpommern mit Erstnachweis der Grobgerippten Körbchenmuschel Corbicula fluminea (O. F. Müller 1756). Mitteilungen der NGM 4(1): 85-89. [in German] PDF fulltext
- Beran L. (2000) "First record of Corbicula fluminea (Mollusca: Bivalvia) in the Czech Republic". Acta Societatis Zoologicae Bohemicae 64: 1-2.
- (Czech) Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. [Annotated list of mollusc species recorded outdoors in the Czech and Slovak Republics]". Malacologica Bohemoslovaca, Suppl. 1: 1-37. PDF.
- Beran L. (2006). Spreading expansion of Corbicula fluminea (Mollusca: Bivalvia) in the Czech Republic. – Heldia 6 5/6: 187-192.
- Hayden, B. and Caffrey, J.M. 2013. First recording of the Asian Clam (Corbicula fluminea (Müller, 1774)) from the River Shannon, with preliminary notes on population size and class distribution. Ir. Nat. J. 32: 29 - 31.
- Vázquez A. A. & Perera S. (2010). "Endemic Freshwater molluscs of Cuba and their conservation status". Tropical Conservation Science 3(2): 190-199. HTM, PDF.
- Martítnez E, Rafael. 1987: Corbicula manilensis molusco introducido en Venezuela. Acta Científica Venezolana 38:384-385
- Ojasti, Juhani., González Jiménez, Eduardo, Szeplaki Otahola, Eduardo. y García Román, Luis B. 2001: Informe sobre las especies exótica en Venezuela. Ministerio del Ambiente y de los Recursos Naturales Caracas. 207p. ISBN 980-04-1254-9
- Lasso, Carlos A., Martínez E, Rafael, Capelo, Juan Carlos., Morales Betancourt, Mónica y Sánchez- Maya, Alejandro. 2009: Lista de los moluscos (Gastropodos_Bivalvia) dulceacuícolas y estuarinos de la cuenca del Orinoco (Venezuela). Biota Colombiana, 10(1 -2):63-74.
- It is not entirely clear that this is the correct name (Jueg & Zettler, 2004)
- Jueg & Zettler (2004), and see "External links"
7. ^ Weitere, M. et al. (2009) Linking environmental warming to the fitness of the invasive clam Corbicula fluminea, Global Change Biology, Volume 15 Issue 12, Pages 2838 - 2851