For the genetic analyses PSR was
defined as the day of death for each fish. We also recorded HW in 41,597 genetically related individuals of the
challenged fish from the same breeding population. A linear bivariate animal model was used to estimate (co)-
variance components and to calculate genetic parameters. Estimated heritabilities for PSR and HW were
0.16 ± 0.04 and 0.41 ± 0.03, respectively. The genetic correlation between PSR and HW was −0.50 ± 0.13.
The levels of genetic variation detected in the present study indicate that selective breeding for these traits is feasible.
However, the magnitude and direction of the genetic correlation between PSR and HWmust be taken into
account when selecting both traits simultaneously.