Heritability (h
2
) estimates for body weight were relatively stable
across time of recordings and generations (Table 7), and of similar magnitude (0.40±0.04) when analyzing all harvest data combined. The h
2
of pond survival was considerable lower (0.05±0.01 and 0.08±0.11,
respectively), but suggested a significant additive genetic component
(Table 8), while that of cold-water tolerance was intermediary
(0.20±0.04 and 0.30±0.31, respectively) when estimated on the
observed and underlying scales. When including all available data in
the analysis (G0–G4), the effect common to full-sibs (c
2
) accounted for