Selective breeding in aquaculture

Abstract

Abstract The basic techniques for selective breeding with cultured aquatic species were described and apparently practiced very early in the annals of aquaculture history; however, this approach has not been utilized in modern aquaculture as prevalently or as effectively as with terrestrial agricultural species. A large part of the aquaculture industry relies on naturally produced organisms as the primary source of seed‐stock, a practice with several negative aspects that limit the production potential of aquaculture species. Selective breeding could be very beneficial to the aquaculture industry in providing the efficient, domesticated stocks that are needed to enhance production. The process of selective breeding is very similar to architecturally creating a structure of original design with available materials. By using the gene differences as “building blocks,” organisms containing the genes which will produce the most beneficial characteristics can be “constructed” and propagated. Although there are many factors that can influence the recognition and use of genetic variation, quantitative genetic methods have been developed to estimate the important genetic components and provide information on which to base selection and breeding decisions. Aquacultural species appear to contain adequate amounts of genetic variation to warrant the use of selective breeding as an approach to creation of improved stocks. In addition, most species exhibit several other biological characteristics that would seem to enhance the likelihood of beneficial results. Although these traits and the results of early selective breeding work with fish suggested that large improvements could be made with aqua‐cultural species, several shortcomings in genetic research and its use have been identified that limited the effectiveness of this approach for aquaculture. Increased efforts are needed to (a) broaden the number of traits on which genetic information is available, (b) increase the number of species on which there are reliable genetic data, and (c) enhance the validity of genetic parameter estimates. Results from a limited number of selective breeding programs designed to increase growth have, generally, shown increases in excess of what has been obtained with agricultural animals. However, the short duration of these studies make assessment of continued response difficult. Effective utilization of selective breeding in the future will require the aquaculture industry to develop some level of “in‐house” expertise and an organization that will facilitate the availability of improved stocks. New techniques for manipulation of the genetic constitution of aquacultural species will provide unique gene combinations for future selective breeding as well as enhance the opportunities for additional stock improvement. A more complete and informed use of selective breeding in aquaculture will enable the industry to meet future market demands and effectively respond to the inevitable changes that will occur.