Common carp Cyprinus carpio is one of the principal cultured
species in China. The production of cultured common carp
reached 2.05 million ton in 1999 and accounted for 20% of total
freshwater fish production. Since the farming of this fish extends
back to ancient times, common carp has a wide distribution in
China. As a result of long-term selection (both natural and
artificial), common carp populations have acquired a great deal
of genetic diversity – there is a great deal of polymorphism in
its phenotype and genotype and its genetic structure has high
heterozygosity. This heterosis provides the opportunity to
improve the productivity of carp through selective breeding.
The utilization of heterosis in selective breeding is an effective
way to improve fish quality and increase fish production. Since
1970s, Chinese fisheries scientists have made broad studies on
the utilization of heterosis in common carp and achieved
significant results. Traits in which crossbreeds express heterosis
include improved survival, growth and tolerance to cold and
specific diseases. The followings are some hybrids of common
carp that have been successfully extended to the practice