Effects of stocking density on survival, growth and size variation of juvenile Brachymystax lenok (Pallas, 1773)

In this experiment the effects of stocking density on growth and survival of juvenile Brachymystax lenok were studied. Experimental fishes were reared at different stocking densities (5, 25, 50 and 75 fish L⁻¹) for 40 days at ambient temperatures (11.2-16.4°C). During the experiment, dissolved oxygen (DO) was above 5.4 mg L⁻¹ and other major environmental factors were controlled at the same levels in each aquarium (DO 5.4-7.2 mg L⁻¹, pH 6.6-7.4, and flow-through rates 0.3-0.4 L s⁻¹). Mortality data in each group was recorded daily and random samples of 30 juveniles were measured and weighed every 10 days. All statistical analyses were performed by anova. The survival rate was found to be significantly affected by stocking density, but not the condition factor (CF), specific growth rate (SGR) or coefficients of variation (CV).The results demonstrate that lenok juveniles can be reared at higher stocking densities, which can increase survival under intensive conditions.