Review of the genetics and the potential for selective breeding of commercially important bivalves

The domestication of species used in aquaculture will not be complete until we have control over all aspects of their biology including their genetics. For virtually all shellfish, we are at present far from having that control but significant advances have been made in the past few years towards understanding many aspects of their genetics. In this paper will be presented a review of recent advances in, and an assessment of the state-of-the-art of shellfish breeding. Breeding here is meant to imply that we are concerned with the genetic control, manipulation and improvement of traits of commercial interest.The ultimate objective of the breeder is to produce strains which are genetically improved. There are several studies which give us an indication of the potential of such selective breeding both through heritability studies and experimental selections. These studies indicate that there is the expected potential and that what is needed next is a major commitment to develop selected lines. The various aspects of bivalve genetics such as Mendelian genetics, population genetics and quantitative genetics will be reviewed in the light of their roles in breeding for the improvement of the economic value of shellfish.