Inter‐specific hybridization between Black Sea trout (Salmo labrax Pallas, 1814) and rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

Thermal shock‐induced triploid and unshocked control hybrids between rainbow trout (Oncorhynchus mykiss) and Black Sea trout (Salmo labrax) and their parental species were produced under hatchery condition by using heat shocks. Triploidization reduced eyed egg rate and alevin yield in all groups. Low survival rate was observed in both shock‐induced triploid hybrid and non‐shock‐induced control hybrids. Although hybrids demonstrated low body weight during the first feeding stage, they reached higher body weight by day 200 when compared with Black Sea trout and rainbow trout. A higher specific growth rate was calculated as 3.60 in the triploid hybrid groups, 1.41 in 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 favourable MPH was detected for specific growth rate and weight in hybrids.