ARTIFICIAL REPRODUCTION OF JUVENILES IN TEMPORARY HATCHERY COMPLEX

Abstract

A technology for cultivating viable juveniles in a temporary hatchery complex near the spawning areas in the Yenisei basin is described for the first time. It has been developed at the Scientific Research Institute of Ecology of Fishery Reservoirs, Krasnoyarsk. The work was conducted on the right tributaries of the Yenisei, the Agul and Mana rivers, in 2010-2014. The temporary fish breeding complex is designed for obtaining and rearing the planting material of freshwater fish species for the purposes of artificial reproduction and field research. It has equipment, which allows conducting the entire complex of fish breeding autonomously. The novelty of this biotechnology is the technical solution of the fish breeding work, which allows obtaining viable fish juveniles at relatively small costs to stock natural water bodies. We have identified spawning temperatures for lenok Brachymistax lenok (Pallas, 1773) of 8.2-9.0 °C, and taimen Hucho taimen (Pallas, 1773) of 6.8-8.6 °C. We have improved the technique for in vivo obtaining of spawn of Siberian grayling Thymallus arcticus (Pallas, 1776), lenok and taimen, using anesthesia (suspension of clove oil), and returning fish to the natural environment. We have defined incubation periods of taimen and lenok, temperature conditions for all fish breeding processes, and feeding regimes for these species. We provide the ways of water treatment and prevention of fungal and bacterial diseases of fish. The results are shown for juvenile salmon fishes. In all for 2010-2014, 869443 samples of grown-up juveniles were delivered to the Yenisei basin including 21677 samples of lenok, 267123 of taimen, and 580700 of Siberian grayling.