A comparison of survival and growth of two strains of chinook salmon (Oncorhynchus tshawytscha) and their crosses reared in confinement

The growth rate and survival of the Capilano (hatchery) and Harrison (wild) strains of chinook salmon ( O. tshawytscha ) of British Columbia and their hybrids reared in confinement were compared both during the fresh-water phase and the sea-water phase. Eggs stripped from the Capilano females had better fertility, fingerlings of the Capilano strain were heavier at 25 weeks of age and had a higher average specific growth rate. The Capilano fish were also heavier both in live weight and gutted weight after 1.5 years in sea-pens. No heterosis was detected for any of the traits measured. Cross-means for body weight and specific growth rate tended to be similar to the strain-of-sire mean.