Taimen Hucho taimen (Pallas, 1773) of the Yenisei basin: aquaculture works 2025

In May-July 2025, work was carried out on the artificial reproduction of the Hucho taimen (Pallas, 1773) of the Bakhta River, the right tributary of the Yenisei in the Evenkiysky Municipal District of the Krasnoyarsk Territory. The capture of productive fish was carried out in late May – early June at the water temperature of 4.6-6.7 °C with spinnings. Taimen males aged 6-7 years, and females aged 10-11 years, were used for fish farming. Spawning temperatures of taimen – 7.9-9.4 °C in the Bakhta River have been identified, and a technique has been developed for the lifetime production of taimen caviar using anesthesia (clove oil suspension) and the return of fish to their natural environment after rehabilitation measures. It was noted that ovulation occurred at a temperature of 7.9 °C and the water level was decreased. Caviar production, its insemination, incubation and larval rearing were carried out according to standard methods of work in salmon farming using their own developments. The incubation time of taimen caviar on the Bakhta River was 209-245 degree days at a water temperature of 7.6-14.2 °C. The period of resorption of the yolk sac averaged 110 degree days at a water temperature of 13.5-18.1 °C. During the mixed feeding, the larval were fed with live food (zooplankton). Artifi-cial feeds (with a fraction of 0.2-0.4) and minced fish (grayling) were used for feeding. From the moment of mass hatching to reaching a weight of 216 mg, the aging and rearing periods were 256 degree days (16 days). The growing time of larval was 150 degree days (9 days) before release into the natural environment. In total, about 6 thousand specimens of taimen larval were grown and released into the Bakhta River.