they reached higher
body weight by day 200 when compared with Black
Sea trout and rainbow trout. A higher speci¢c
growth rate was calculated as 3.60 in the triploid hybrid
groups,1.41in the triploid Black Sea trout groups
and 2.27 in the triploid rainbow trout groups between
days 110 and 200. A lower condition factor
was determined in the hybrid than in the diploid parental
species. A negative value of mid-parent heterosis
(MPH) performance was deected for condition
factor, and a favourableMPHwas detected for speci¢c
growth rate and weight in hybrids.