The integrated development and application of controlled reproduction techniques in Pacific salmonid aquaculture.

During the last several years there has been rapid progress in the development and application of controlled reproduction and associated biotechnologies to the culture of salmonids. This review focuses on the development of those techniques for Pacific salmon (Oncorhynchus species) and rainbow trout (Salmo gairdneri). These include methodologies for the induction of ovulation, storage of gametes, chromosome set manipulation, i.e., induced gynogenesis and triploidy, hormonal feminization, hormonal sterilization and hormonal masculinization of genotypic females to produce milt containing only female spermatozoa.The current and future applications of these methodologies to the commercial mariculture of salmonids and to the enhancement and management of ocean and fresh water stocks are described. The implementation of each individual methodology for the control of reproduction can in itself have a significant impact on the efficiency of culture systems. It is, however, from the combination of specific complementary methods in production systems that the greatest gains will ultimately be made.It is concluded that the utilization of single or paired controlled reproduction techniques by themselves or in combination with other biotechnologies (e.g. sterilization plus growth acceleration) offer significant advantages for both the commercial mariculture of salmonids and the rearing of salmonids by government agencies for release into the oceanic or lacustrine environment.