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

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 gene tic correlations in pair-wise comparisons of stress exposures. Genetic corr elations between lysozyme and cortisol in stressed rainbow trout tended to be negative, although insignificant. Neither lysozyme, nor cortisol exhibit ed significant correlations with serum haemolytic activity, It is concluded that the data do not confirm earlier suggestions that lysozyme should be s uperior to cortisol in consistency of stress response in rainbow trout. (C) 1999 The Fisheries Society of the British Isles.