Effects of stocking density on growth,survival and behavior of juvenile Siberian charr Salvelinus leucomaenis

The juvenile Siberian charr Salvelinus leucomaenis was cultured at 4 different stocking densities of 3.33,6.93,10.01 kg/m3 and 13.65 kg/m3 for 48 days to evaluate the influences of stocking density on growth,survival and behavior.The results showed that there were no significant effects on survival and condition factor,but significant effect on the variation in growth(P=0.001).There was a positive correlation between the body weight coefficient variation and the stocking density(CV= 0.288SD-5.999,R=0.875,P=0.004).The specific growth rate was diminished with the increase in stocking density,with significant negative correlation(SGR=15.220-5.908SD,R=-0.832,P=0.005) and the net gain was increased with the increase in stocking density(P=0.000).The behavior was,to some extent,affected by stocking density.The fishes feeding at the bottom at lower density had lower aggregation,and more uneaten food and were sensitive to the environmental stimulus including light,and sound.There was more frequency in aggregation in higher density than that in lower density,leading to irritable.