Selective Breeding

Selective breeding is the process of breeding plants and animals for particular traits. Typically, strains that are selectively bred are domesticated, and the breeding is ordinarily done by a professional breeder. The cross of animals results in what is called a crossbreed.

Selective breeding in aquaculture specifically holds high potential for the genetic improvement of fish and shellfish for foodstuff. For example, aquaculture species are reared for particular traits such as growth rate, survival rate, meat quality, resistance to diseases and age at sexual maturation, along with other traits such as shell size & colour, etc.

With regards to ornamental species, most aquarium fish are selectively bred forms that have never actually existed in the wild. This is especially noticeable in species such as the humble goldfish (and it's variants) and guppies, where there is a tendency to produce unusual colours and fin patterns. In the wild, these brighter individuals would be quickly removed by predators but in the safety of an aquarium, mutations such as albinism can be fixed by careful selective breeding. This means that the natural habitat of most aquarium fish is, in fact, an aquarium!