Genetic differences in growth and survival between strains and hybrids of rainbow trout ( Salmo gairdneri) stocked in aquaculture lakes in the Canadian prairies

Several thousand small, shallow, highly productive lakes across the Canadian prairies are used by farmers for commercial and recreational production of rainbow trout. This report summarizes the results of evaluations of genetic differences between strains of trout from 1972 to 1978. Strains of fish were obtained from the wild and from private and government hatcheries in Canada, the U.S.A., and Europe. Matched plantings of different strains were made in several experimental lakes annually and growth and survival were determined. The relative effects of strains (genetic effect), lakes (environment effects) and strain × lake interactions were determined in each study. Significant hybrid vigour for both growth and survival was observed for some but not all crosses.