The focus of the study was to analyze the effects of the artificial reproduction of whitefish, Coregonus lavaretus (L.) aged from 1+ to 4+. It was confirmed that males comprised 64.5% of the brood stock. The males were sexually mature at the age of 1+, while most females were mature at the age of 2+. The females gained weight faster in comparison to the males, and the differences were highly statistically significant (P < 0.001). Survival during the period from the first spawning at age 1+ to spawning at age 4+ was 79.6% for males and 59.6% for females. The quantity of eggs obtained, the egg size, and their survival during incubation all increased as the fish aged. The weight of the eggs obtained from fish aged 3+ and 4+ was statistically significantly higher that from younger fish (1+ and 2+) (P < 0.001). The results of the current study indicate that exploiting a whitefish brood stock under controlled conditions can begin as early as at age 2+. The highest relative fecundity and largest egg size were obtained in females aged 3+.
