According to Kirpichnikov (1999) the common carp is divided into three subspecies: the European subspecies Cyprinus carpio carpio, the Far Eastern subspecies Cyprinus carpio haematopterus and the South-East Asian subspecies Cyprinus carpio viridiviolaceus(Fig. 3). Microsatellite polymorphism data suggest an ancient separation of European/Central Asian from East/South-East Asian carps and a single origin of European carp in Central Asia as already inferred from previous allozyme and mitochondrial DNA (mtDNA) restriction fragment length polymorphism (RFLP) studies (Kholman et al. 2005). According to Kholman et al.(2005) the taxonomic status of subspecies assigned to European (C. c. carpio) and East Asian carp (C. c. haematopterus) is supported. However, because of its close relationship to European carp, it is generally thought that Central Asian carp does not deserve a separate subspecies status (i.e. C. c. aralensis).
Asian carp diversity in aquaculture
There are many hypotheses about the origin of common carp in Asia. China has a long history, at least 2500 years, of culturing common carp (Balon 2006). There are now many varieties of common carp that are commonly used for aquaculture in India, Indonesia, Bangladesh, Thailand and Vietnam. The species is distributed naturally in rivers, lakes, reservoirs and swamps. It is also cultured in ponds and ditches and in cages in rivers, lakes and reservoirs. In addition, the concurrent and rotational culture of rice and fish using common carp has its origin in Asia (Halwart & Gupta 2004).
In China, examples of common carp varieties (see Table 1) include Cyprinus carpio wuyuanesnsis, Cyprinus carpio singuonensis, Jian carp (Cyprinus carpio var. jian) and mirror carp among many others. Selection, crossing, gynogenesis, polyploidy, gene transfer and introducing alien varieties have been used for carp genetic improvement and have resulted in advances in production and economical benefits.
Table 1. List of the 20 varieties of common carp approved for extension by the Chinese National Certification Committee for Aquatic Varieties (Lou 2001)
|Hebao red carp||Cyprinus carpio var. wuyuanensis||Selection||Aquaculture, parent fish for breeding|
|Xingguo red carp||Cyprinus carpio var. singuoensis||Selection||Aquaculture, parent fish for breeding|
|Huanghe carp||C. c. haematopterus||Selection||Aquaculture|
|Wan’an transparent red carp||C. carpio var. wananensis||Selection||Aquaculture|
|Jian carp||Cyprinus carpio var. jian||Selection, crossing, gynogenesis||Aquaculture|
|Anti-cold strain of Hebao red carp||C. carpio var. wuyuanensis♀ and Heilongjiang local common carp||Selection, crossing||Aquaculture|
|Selected strain of Germany mirror carp|| ||Selection||Aquaculture, parent fish for breeding|
|Selected strain of scattered mirror carp|| ||Selection||Aquaculture, parent fish for breeding|
|Songpu carp||C. carpio var. wuyuanensis, Heilongjiang local common carp, Germany mirror carp, scattered mirror carp||Selection, crossing, gynogenesis||Aquaculture|
|Xiangyun carp|| ||Triploid||Aquaculture|
|Songhe carp||C. carpio var. wuyuanensis, Heilongjiang local common carp, scattered mirror carp||Selection, crossing, gynogenesis||Aquaculture|
|Feng carp||C. c. var. singuonensis♀ and Scattered mirror carp ♂||Hybrid||Aquaculture|
|Heyuan carp||C. carpio var. wuyuanensis♀ and C. carpio var. yuankiang♂||Hybrid||Aquaculture|
|Tri-crossed carp||(C. carpio var. wuyuanensis♀ and C. carpio var. yuankiang♂) ♀ and Scattered mirror carp ♂||Hybrid||Aquaculture|
|Ying carp||Scattered mirror carp ♀ and nuclear-cytoplasmic hybrid fish f2♂||Hybrid||Aquaculture|
|Yue carp||C. carpio var. wuyuanensis♀ and Xiangjiang local species ♂||Hybrid||Aquaculture|
|Lotus carp||Scattered mirror carp ♀ and C. c. var. singuonensis♂||Hybrid||Aquaculture|
|Molong carp||Koi species||Selection, crossing||Ornamental fish|
|Germany mirror carp||Introduced from Germany||Domestication||Aquaculture, parent fish for breeding|
|Scattered mirror carp||Introduced from Russia||Domestication||Aquaculture, parent fish for breeding|
National natural ecological pools (gene banks) have been created to preserve, develop and utilize the germplasm resources of common carp in China, for example, Heilongjiang local common carp, Wuyuan hebao red carp and Xingguo red carp, Huanghe common carp, and Xiangjiang local common carp in the provinces of Heilongjiang, Jiangxi, Henan and Hunan, respectively (Lou 2001). These gene banks play an important role in the conservation of genetic resources and in the extension of broodstock and quality seed.
The Chinese National Certification Committee for Aquatic Varieties is an organization that was established to evaluate genetic resources, broodstock, seed quality, alien species and hybrids in China. The committee has approved more than 60 breeds to be distributed through extension programmes around China. Among them are 20 varieties/hybrids/alien strains of common carp (Table 1) (Lou 2001).
Common carp is one of the most important fish cultured throughout Bangladesh and the varieties cultured are the scaly carp Cyprinus carpio var. communis, the mirror-carp Cyprinus carpio var. specularis and the leather carp Cyprinus carpio var. nudus(Hussain & Mazid 2005).
Cyprinus carpio is also one of the three major species cultured and caught in the inland waters of Thailand. This species is found naturally throughout the country in rivers, reservoirs and swamps. It is also cultured in ponds, paddy fields and ditches (Pongthana 2005).
Its hardiness, fast growth, easy propagation, omnivorous feeding habit, ability to readily accept supplementary feed, resistance to disease and tolerance of a wide range of climatic conditions have made common carp a popular species in India, where production reached 443 000 t in 2003. Production is mostly based on two introduced strains, the Prussian and Bangkok (Reddy 2005), and the many farm stocks that have evolved from them through the continuing process of domestication.
Common carp is a popular indigenous cultured cyprinid species in Vietnam, particularly in North Vietnam where it is readily marketable and commands a good price. There are eight local varieties of C. carpio in Vietnam. The local varieties, identified on the basis of morphology and coloration are: white scaled, Bac Can, Ho Tay, South Hai Van, Red, Violet, High Body Depth and Scattered Scale (Dan et al. 2005).
Similarly, C. carpio is one of the most economically important species for aquaculture in Indonesia; several strains that vary in colour and body form are cultured in Indonesia. Culture of C. carpio began in the middle of the 19th century and it is cultivated in ponds, rice fields, bamboo or wooden cages in rivers and floating net cages in lakes and reservoirs. Presently, common carp is cultured in all provinces of Indonesia and comprises 50.8% of total fish production (Emmawati et al. 2005).
Intraspecific hybridization of common carp has been conducted in Japan since the late 1960s. Six crossing groups with different varieties, including local strains, mirror carp and scale carp from Europe and China, have obvious heterosis (Lou 2001). Artificial selection and hybridization have been used to improve different strains of Koi carp and 100 strains have been bred as ornamental fish.
European carp diversity in aquaculture
European strains of common carp are derived from wild carp of the Danube valley. Productive populations were domesticated from ancestral forms, as well as from their mutual crosses and backcrosses followed by mass selection. These populations have been widely spread throughout the continent (Fig. 4). The earliest attempts at culture date back to the Roman Empire and the spread of Christianity in Europe, and this is where domesticated forms were later introduced to other continents (Balon 2006). At present, the main common carp producer countries in Europe are: Russia, Ukraine, the Czech Republic, Poland, Hungary and Germany (FAO 2009a).
Pokorny et al. (1995) reported 12 ‘original’ Czech common carp populations that were bred in the 1930s, 1940s and 1950s as well as 11 breeds imported from neighbouring countries. Ten hybrids, developed from pure breeds, are also maintained in the live gene bank of the Research Institute for Fisheries at Vodnany. Nine pure breeds of common carp have been considered to be important genetic resources and are used in farming in the Czech Republic (Flajšhans et al. 1999).
In Hungary, work on the genetics and selection of common carp resulted in collections of strains during the 1970s and 1980s. Bakos and Gorda (1995) reported that 15 Hungarian and 15 foreign strains were maintained in the live gene bank in Hungary. Three highly productive hybrids were produced using the genetic resources maintained in the live gene bank. By the mid 1980s, 80% of carp production in Hungary was based on these three hybrids (Bakos & Gorda 1995).
In Poland, the live gene bank at the Institute of Ichthyobiology and Aquaculture at Golysz, comprises 19 breeding lines with considerable genetic variation in survival rate, forming a strong basis for genetic improvement. Out of these 19 lines, five are Polish and 14 are ‘foreign’: five Hungarian lines, two Ukrainian lines, two Lituanian lines, one line each from Israel, France, Germany and Yugoslavia, and one ornamental line (Irnazarow 2008).
In Germany, aquatic genetic resources are described at the following website: http://www.genres.de/genres_eng/agr/agr_index.htm. The National Inventory for Aquatic Genetic Resources is available in German at http://agrdeu.genres.de/agrdeu/index. This inventory lists all German common carp broodstocks genetically characterised by microsatellites to date. No live gene banks exist for carp in Germany and local carp farmers maintain the strains. Currently, financial support is not available for maintaining such strains. However, this may change in the near future. Farmers will then get limited support for keeping strains if they meet specific conditions, such as, for example, minimum broodstock sizes. No state-approved strains exist in Germany at present (Klaus Kholman, pers. comm., 2009).
Bogeruk (2001) described 14 Russian strains of common carp, officially recognised by the Russian State. In a recent study, Bogeruk (2008) gave an overview of carp breeds in seven important carp-producing countries, with detailed data on biology, genetics, production and other parameters. In total, 60 ‘national strains’ (including four wild strains) and 25 ‘foreign strains’ are described in the Catalogue of Carp Breeds (Cyprinus carpio L.) of the countries of central and eastern Europe by Bogeruk (2008); these breeds are summarised in Table 2.
Table 2. Genetic resources of common carp in major European carp-producing countries based on Bogeruk (2008)
|Country Strains||Belarus||Czech Republic||Hungary||Moldova||Poland||Russia||Ukraine|
|Foreign||5|| 8||NR||NR||11|| 1||NR|