''Corbicula'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mi ...

and

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

water

clam Clam is a common name for several kinds of bivalve mollusc. The word is often applied only to those that are deemed edible and live as infauna, spending most of their lives halfway buried in the sand of the sea floor or riverbeds. Clams h ...

aquatic Aquatic means relating to water; living in or near water or taking place in water; does not include groundwater, as "aquatic" implies an environment where plants and animals live. Aquatic(s) may also refer to: * Aquatic animal, either vertebrate ...

bivalve Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

s in the family Cyrenidae, the basket clams.Gofas, S. (2015). Cyrenidae Gray, 1847. In: MolluscaBase (2015). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=238370 on 2015-08-26 The genus name is the

Neo-Latin Neo-LatinSidwell, Keith ''Classical Latin-Medieval Latin-Neo Latin'' in ; others, throughout. (also known as New Latin and Modern Latin) is the style of written Latin used in original literary, scholarly, and scientific works, first in Italy d ...

diminutive of

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''corbis'', a basket, referring to the shape and ribs of the shell. The genus ''Corbicula'' includes numerous extant and

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

species; the status of several of them is unclear (''

species inquirenda In biological classification, a ''species inquirenda'' is a species of doubtful identity requiring further investigation. The use of the term in English-language biological literature dates back to at least the early nineteenth century. The ter ...

'').MolluscaBase eds. (2022). ''Corbicula'' Megerle von Mühlfeld, 1811. Accessed through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=238371 on 2022-05-29 The best known is ''

Corbicula fluminea ''Corbicula fluminea'' is a species of freshwater clam native to eastern Asia which has become a successful invasive species throughout the world, including North America, South America, Europe, and New Zealand. It is native to freshwater enviro ...

'', an

invasive species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

in many areas of the world. Unusually, some members reproduce via

androgenesis Androgenesis is a system of asexual reproduction that requires the presence of eggs and occurs when a zygote is produced with only paternal nuclear genes. During standard sexual reproduction, one female parent and one male parent each produce h ...

, wherein all genes are inherited from the male, one of the very few animals to do so. In many Asian countries, these clams are used as ingredients for soup. In

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

, there is popular soup made of these species of clams (usually '' Corbicula japonica,

Corbicula leana ''Corbicula leana'', known as ''chamjaecheop'' (; "true '' jaecheop''") in Korean and as ''mashijimi'' (; "true '' shijimi''") in Japanese, is a species of freshwater and brackish water clams, distributed in the Korean Peninsula and the Japanese ...

'') known as 재첩국 (jaechup-guk).

Androgenesis

Androgenesis occurs rarely in the tree of life, with only a few occurrences documented and multiple mechanisms through which it is achieved. In ''Corbicula'', androgenesis occurs through the ejection of maternal

chromosomes A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most importa ...

from the

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

following fertilization by sperm. Fertilization in androgenetic and sexual lineages of ''Corbicula'' occurs while the developing egg is arrested at metaphase 1 of

meiosis Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one c ...

. In sexual species of ''Corbicula'', the axis of the meiotic spindle orienting the duplicated maternal chromosomes is perpendicular to the

plasma membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...

of the

zygote A zygote (; , ) is a eukaryote, eukaryotic cell (biology), cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individ ...

. However, androgenetic lineages of ''Corbicula'' have an axis parallel to the membrane. As a result of this unusual orientation, the two maternal

polar bodies A polar body is a small haploid cell that is formed at the same time as an egg cell during oogenesis, but generally does not have the ability to be fertilized. It is named from its polar position in the egg. When certain diploid cells in animal ...

formed during anaphase 1 are extruded from the zygote, leading to the complete elimination of all maternal chromosomes. Androgenetic ''Corbicula'' lineages also have unreduced sperm; therefore, these lineages retain the same

ploidy Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

level after maternal chromosome extrusion. Since only maternal chromosomes are eliminated from the zygote, the zygote inherits only the paternal genome. Sperm of sexually reproducing ''Corbicula'' are uniflagellate, which is considered the ancestral trait, while androgenetic ''Corbicula'' lineages interestingly possess biflagellate sperm. While androgenesis would likely lead to species extinction in

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

species, all androgenetic lineages of ''Corbicula'' are

hermaphroditic A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

, meaning individuals can produce both sperm and egg, and these individuals can self-fertilize to create effectively clonal offspring. Androgenetic lineages of Corbicula are capable of cross-breeding with sexual and other androgenetic lineages in a phenomenon known as “egg parasitism”. This leads to several interesting consequences for determining androgenetic Corbicula

phylogeny A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...

. The first is a “cytonuclear mismatch” whereby the

mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...

shows congruence with the parasitized lineage but the

genomic DNA Genomic deoxyribonucleic acid (abbreviated as gDNA) is chromosomal DNA, in contrast to extra-chromosomal DNAs like plasmids. Most organisms have the same genomic DNA in every cell; however, only certain genes are active in each cell to allow for c ...

is congruent with the selfish androgenetic lineage whose sperm fertilized the egg. Further complicating phylogenetic studies is the rare occurrence of partial or complete nuclear capture, when the maternal DNA is not completely eliminated from the zygote. Nuclear capture can result in genome recombination or

polyploidy Polyploidy is a condition in which the cells of an organism have more than two paired sets of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two complete sets of chromosomes, one fro ...

. Partial genome capture has been documented when native and androgenetic or multiple androgenetic lineages are sympatric. Egg parasitism has been offered as one explanation for the persistence of androgenetic lineages through increasing

allele An allele is a variant of the sequence of nucleotides at a particular location, or Locus (genetics), locus, on a DNA molecule. Alleles can differ at a single position through Single-nucleotide polymorphism, single nucleotide polymorphisms (SNP), ...

heterozygosity Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Mos ...

Taxonomy

Despite extensive phylogenetic study of the genus, appropriate categorization of invasive populations has remained a challenge. Lack of clarity in their phylogeny may be due to being hermaphroditic androgens, though no single species of ''Corbicula'' has been described as fully androgenetic. Rather, 4-5 specific androgenetic lineages are described in the scientific literature. Form A, B, and D are found within the

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

; Form C is in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

; and another form(s) has described in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Cross-breeding A crossbreed is an organism with purebred parents of two different breeds, varieties, or populations. A domestic animal of unknown ancestry, where the breed status of only one parent or grandparent is known, may also be called a crossbreed though ...

between androgenetic and native ''Corbicula'' lineages have made it difficult to create a clear taxonomy of the genus, and it is still unclear whether androgenesis arose independently multiple times or originated from a smaller number of lineages that then cross-bred with sexual ''Corbicula'' species.

Invasiveness

''Corbicula'' clams are remarkably proficient

, with native ranges spanning from Australia to Africa, but can now be found in most other continents. In North America, ''Corbicula'' may have initially invaded as a human food source, though the origin of invasion in other continents has not been determined. However, genotyping may aid in tracking the number of introductions occurring in non-native habitats. Part of what contributes to its invasive success is its androgenetic reproductive strategy, wherein a single individual may be capable of creating an entire population, but beyond androgenesis, ''Corbicula'' owe their invasive potential to anthropogenic factors and their life history strategies. ''Corbicula'' have high reproductive capacities, which may be in part due to their ability to self-fertilize, and the high dispersal potential of their larvae. ''Corbicula'' are also phenotypically plastic, which may allow them to outcompete native mussels, and their occurrence at high densities may drive native mussel

glochidia The glochidium (plural glochidia) is a microscopic larval stage of some freshwater mussels, aquatic bivalve mollusks in the families Unionidae and Margaritiferidae, the river mussels and European freshwater pearl mussels. These larvae are t ...

mortality. Their high competitive ability is of concern, in part due to the already endangered status of many of the world’s mussel species. Though ''Corbicula'' are proficient

competitors Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

, they have a small number of lineages, and have worldwide low genetic diversity, which is attributed to their reproductive capabilities. While this generally does not contribute to their success, phenotypic plasticity may buffer them from the effects of low genetic diversity, though it is suggested that population bottlenecks may have occurred during their invasions. Despite the potential for population bottlenecks, there is a need for better control methods, as active spread has occurred. While some eradication methods work, such as deposition of dry ice pellets, the use of a heat torch, and temperature shock, preventative measures are of utmost importance as invasives are often difficult to detect prior to establishment.

Species

Extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

species within the genus ''Corbicula'' include: * '' Corbicula africana'' (Krauss, 1848) * '' Corbicula angulifera'' E. von Martens, 1897 * '' Corbicula anomioides'' (Bogan & Bouchet, 1998) * '' Corbicula astartina'' (E. von Martens, 1860) * '' Corbicula aurea'' Nesemann & G. Sharma, 2007 * '' Corbicula australis'' (Deshayes, 1830) * '' Corbicula baudoni'' Morlet, 1886 * '' Corbicula bitruncata'' E. von Martens, 1908 * '' Corbicula blandiana'' Prime, 1864 * '' Corbicula bocourti'' (Morelet, 1865) * '' Corbicula cashmiriensis'' Deshayes, 1855 * '' Corbicula castanea'' (Morelet, 1865) * '' Corbicula consularis'' Prime, 1870 * '' Corbicula cyreniformis'' Prime, 1860 * '' Corbicula dautzenbergi'' Prashad, 1928 * '' Corbicula elatior'' E. von Martens, 1905 * '' Corbicula elongata'' Clessin, 1878 * '' Corbicula erosa'' Prime, 1861 * '' Corbicula ferghanensis'' Kursalova & Starobogatov, 1971 * '' Corbicula fluminalis'' (O. F. Müller, 1774) * ''

'' (O. F. Müller, 1774) – Asian clam * '' Corbicula formosana'' Dall, 1903 * '' Corbicula gabonensis'' Preston, 1909 * '' Corbicula gustaviana'' E. von Martens, 1900 * '' Corbicula iravadica'' Blanford, 1880 * '' Corbicula japonica'' Prime, 1864
* ''

Corbicula javanica ''Corbicula'' is a genus of freshwater and brackish water clams, aquatic bivalve mollusks in the family Cyrenidae, the basket clams.Gofas, S. (2015). Cyrenidae Gray, 1847. In: MolluscaBase (2015). Accessed through: World Register of Marine Sp ...

'' (Mousson, 1849) * '' Corbicula lamarckiana'' Prime, 1864 * '' Corbicula largillierti'' (Philippi, 1844) * '' Corbicula larnaudieri'' Prime, 1862 * ''

'' (Prime, 1864) * '' Corbicula leviuscula'' Prime, 1864 * '' Corbicula loehensis'' Kruimel, 1913 * '' Corbicula lutea'' Morelet, 1862 * '' Corbicula lydigiana'' Prime, 1861 * '' Corbicula madagascariensis'' Smith, 1882 * '' Corbicula mahalonensis'' Kruimel, 1913 * '' Corbicula malaccensis'' Deshayes, 1855 * '' Corbicula manilensis'' (Philippi, 1844) * '' Corbicula maroubra'' (Iredale, 1943) * '' Corbicula masapensis'' Kruimel, 1913 * '' Corbicula matannensis'' Sarasin & Sarasin, 1898 * '' Corbicula messageri'' Bavay & Dautzenberg, 1901 * '' Corbicula moltkiana'' Prime, 1878 * '' Corbicula moreletiana'' Prime, 1867 * '' Corbicula mortoni'' M. Huber, 2015 * '' Corbicula nitens'' (Philippi, 1844) * '' Corbicula noetlingi'' E. von Martens, 1899 * '' Corbicula ovalina'' Deshayes, 1855 * '' Corbicula poppei'' Thach & F. Huber, 2021 * '' Corbicula possoensis'' Sarasin & Sarasin, 1898 * '' Corbicula pulchella'' (Mousson, 1849) * '' Corbicula pullata'' (Philippi, 1850) * '' Corbicula rectipatula'' B.-Y. Huang, 1981 * '' Corbicula regia'' Clessin, 1879 * '' Corbicula rivalis'' (Philippi, 1850) * '' Corbicula sandai'' Reinchardt, 1878 * '' Corbicula senegalensis'' Clessin, 1877 * '' Corbicula siamensis'' Prashad, 1928 * '' Corbicula similis'' (W. Wood, 1828) * '' Corbicula solida'' Clessin, 1887 * '' Corbicula solidula'' Prime, 1861 * '' Corbicula straminea'' Reinhardt, 1877 * '' Corbicula striatella'' Deshayes, 1855 * '' Corbicula subnitens'' Clessin, 1887 * '' Corbicula subplanata'' E. von Martens, 1897 * '' Corbicula tenuis'' Clessin, 1887 * '' Corbicula tibetensis'' Prashad, 1929 * '' Corbicula tobae'' E. von Martens, 1900 * '' Corbicula towutensis'' Kruimel, 1913 * '' Corbicula tsadiana'' E. von Martens, 1903 * '' Corbicula virescens'' Brandt, 1974

References

* Bogan, A., Bouchet, P. (1998). Cementation in the freshwater bivalve family Corbiculidae (Mollusca: Bivalvia): a new genus and species from Lake Poso, Indonesia. Hydrobiologia, 389: 131-139 * Suzuki, K.; Oyama, K. (1943). Überblick über die Corbiculiden Ostasiens (Materialien zur Monographic der Ostasiatischen Corbiculiden 1). Venus. 12(3-4): 138–149. * Ota, Y. hta, Y. (1970). A review of some Cretaceous corbiculids in North America. Transactions and Proceedings of the Palaeontological Society of Japan, new series. 79: 291–315.

External links

von Mühlfeld J.C. (1811). Entwurf eines neuen Systems der Schaltiergehäuse. Magazin für die neuesten Entdecklungen in der gesammten Naturkunde von der Gesellschaft Naturforschaft Freunde zu Berlin. 5(1): 38-72, plate 3

Dall, W. H. (1903). Review of the classification of the Cyrenacea. Proceedings of the Biological Society of Washington. 16: 5-8.

Lindholm W.A. (1933). Eine verschollene Muschel aus Zentralasien. Archiv für Molluskenkunde. 65: 264–268

Sandberger, C.L.F. (1870-1875). Die Land- und Süßwasser-Conchylien der Vorwelt. C. W. Kreidel, Wiesbaden.
{{Authority control Cyrenidae Bivalve genera