The Age-Dependent Reproductive Performance of 4th Generation Black Sea Trout (Salmo labrax Pallas, 1814) Females

In this study, the age-dependent reproductive performance of 4th generation of hatchery-origin Black Sea trout (Salmo labrax Pallas, 1814) females was determined with the aim of understanding breeding characteristics of ideal broodstock management plan for Black Sea trout. The 2(+), 3(+), 4(+) and 5(+) years old females (n=131, 104, 63 and 28, respectively) with weights ranging from 919.45 +/- 36.22g to 2439.21 +/- 139.28g were used. Reproductive rates of females (2(+), 3(+), 4(+) and 5(+) years old) were determined as 22.14%, 60.30% and 17.56% for 2(+), 17.47%, 72.82% and 9.71% for 3(+), and 19.05%, 68.25%, and 12.70% for 4(+) years old in November, December and January, respectively. Fertilization rates were obtained 94.31%, 95.02%, 96.03% and 93.39%, respectively. The total fecundity was positively correlated with the age and weight (r=0.84) but negatively with the relative fecundity (r=-0.24). The difference between 2(+) and 3(+) age groups' total fecundities was insignificant, and the 4(+) and 5(+) age groups were different from all groups. In addition, there was no significant difference in fertilization rates among all age groups' rates but the 5(+) age group had slightly lower value (P<0.05). For ideal broodstock management in Black Sea trout production, based on the results of this study, it is recommended to use 3(+) and 4(+) years old females with high breeding efficiency and remove 5(+) years and older females from the broodstock.