Genetic, Environmental, and Interaction Effects on Growth and Stress Response of Chinook Salmon (Oncorhynchus tshawytscha) Fry

Abstract

Eight full- and half-sib families of chinook salmon (Oncorhynchus tshawytscha) were held during egg development at two temperatures (8.0 and 10.2 °C). As fry, these families were measured for relative growth rate, initial and final wet weight, hematocrit values before and 2 h after a 30-s handling stress, and plasma cortisol and glucose concentrations before and after stress. Significant sire effects were found for all measured traits, and significant dam effects were found for all traits except for the poststress increases in cortisol concentrations. There were significant genotype-by-environment interactions for all traits except unstressed (control) plasma glucose concentrations. Incubation temperature had a significant effect on relative growth rate and final wet weight only. We found a significant correlation between poststress plasma glucose concentration and relative growth rate for all fish, independent of family, while resting plasma cortisol concentration and poststress hematocrit correlated with wet weight only when analyzed within the eight individual families. Genetic contributions to stress-related parameters and genotype-by-environment interactions should be considered as a factor in stress-related research with fish.