GROWTH AND SURVIVAL OF RAINBOW TROUT PARASALMO MYKISS WAL. WHEN GROWING IN THE BAY OF THE GREAT ONEGO OF THE ONEGA LAKE (KARELIA, RUSSIA)

Dzyubuk Irina Mikhailovna

The article presents the results on the growth and survival of rainbow trout Parasalmo mykiss Wal., obtained from producers from the Kaluga region (Russia), in the Great Onego Bay of Onega Lake (Karelia). The conditions (temperature, oxygen) for growing rainbow trout were generally favorable, in June they were close to optimal, but in May and some days of July they were close to critical values. Under these conditions, the absolute weight gain was 220 g for yearlings and 520 g for two-year-olds. The intensity of mass accumulation was greater in yearlings than in two-year-olds. The absolute increase in the mass of rainbow trout was greatest in June, under optimal temperature and oxygen conditions of the aquatic environment of the Great Onego Bay. The survival rate of rainbow trout was high (96.6–99.9%). The decrease in the survival rate of rainbow trout yearlings in May is probably due to low water temperatures. Correlation analysis showed a high degree of relationship between growing conditions (temperature, oxygen) and the mass of rainbow trout. An effective increase in mass and a high survival rate of rainbow trout are possible under optimal and close to them temperature and oxygen conditions of the aquatic environment of the Great Onego Bay of Onega Lake. A decrease in absolute weight gain and survival of rainbow trout is observed when the water temperature and oxygen content in water change to values close to critical.

Keywords:cage fish farming, rainbow trout, weight, absolute weight gain, survival rate, Onega Lake