Experimental crossbreeding reveals variation in growth among brown trout (Salmo trutta) strains and their reciprocal crossbreeds

The purpose of the current study was to evaluate culturing potential of Brown trout (Salmo trutta) strains belonging to Danubian lineage and their reciprocal crosses. Using all possible combinations Fl generation crosstypes were produced by crossing Abant (A), Black Sea (L), Caspian (C) and Anatolian (F) strains of brown trout which were previously recognized as different species. Growth performance and growth parameter indices of fourteen out of sixteen cross-types were evaluated. Growth performances of nine of the cross-types were monitored for eighteen months in trial-I, rest of them (5 cross-types) were monitored for ten months in trial-II. The mean weight of fish reached 455.4 +/- 7.27 g (LL) and 87.36 +/- 12.03 g (AF) in first and second trials, respectively. The mean weights of the cross-types were similar at the end of the 18-months in trial-I and no significant difference was observed between cross-types except for CC and CL. The highest growth rate was observed in LL, LA and LC cross-types at the end of the 18-month. The mean weights of the cross-types were similar at the end of the 10-month period in trial-II and no significant difference was observed between cross-types except for FF and FL. The highest growth rate was observed in LL, AF and FA cross-types at the end of the 10-month. The best FCR were calculated for LL, LA, LC and AL cross-types in trial-I and LL, AF and FA cross-types in trial-II. Direction of the crossbreeding and maternal effect appeared to be decisive on growth performance of the cross-types. Along with selective breeding for better growth traits Black-Sea strain (LL), LA, LC and AF cross-types have a promising potential for aquaculture.