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.