Abstract

The possibility to improve productivity in aquaculture by applying selective breeding and hybridization is very good. This is due particularly to large genetic variability in most economically important traits and high fecundity in species of interest. To increase efficiency, individual selection should be combined with family selection. It is concluded that if additive genetic variance is present in economically important traits, selection should be practiced, and if non-additive genetic variance is considerable, selection should be combined with crossbreeding. It is recommended that breeding stations be established to carry out selection programmes. Breeding programmes need considerable investments and operating funds. However, they have been shown to produce very favourable benefit/cost relationships. In an appendix a recording scheme for rainbow trout and a description of how selection is practiced are given.