Poststress levels of lysozyme and cortisol in adult rainbow trout: heritabilities and genetic correlations

Abstract

Lysozyme response in stressed rainbow trout was compared with measurements of poststress cortisol activity. Estimates of heritability of lysozyme and cortisol were both moderate‐to‐high and both traits displayed positive genetic correlations in pair‐wise comparisons of stress exposures. Genetic correlations between lysozyme and cortisol in stressed rainbow trout tended to be negative, although insignificant. Neither lysozyme, nor cortisol exhibited significant correlations with serum haemolytic activity. It is concluded that the data do not confirm earlier suggestions that lysozyme should be superior to cortisol in consistency of stress response in rainbow trout.