The age-dependent reproductive performance of 4th generation black sea trout (Salmo labrax Pallas, 1814) females

Abstract

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.