养殖密度对循环水养殖虹鳟生长和血液生理生化指标的影响

Effects of culture density on physiology and biochemistry of cyclically cultured rainbow trout

文章旨在探究不同放养密度下虹鳟的生理和生化指标差异,为确定循环水养殖虹鳟的适宜密度提供参考。试验将体况相似的600尾健康虹鳟随机分为3组:低密度组(100尾)、中密度组(200尾)高密度组(300尾),分别于第1、23、44天进行生长及生理生化指标测定。中密度组虹鳟终末体质量、增重率、特定生长率均显著高于高密度组(P<0.05)。第1天,高、低密度组虹鳟白细胞数目极显著高于中密度组(P<0.01),高密度组虹鳟乳酸脱氢酶活力极显著高于中、低密度组(P<0.01)。第23和44天,高密度组虹鳟白细胞数目、红细胞数目、谷丙转氨酶活力、总胆红素含量极显著高于中、低密度组(P<0.01),高密度组虹鳟过氧化氢酶活力极显著低于中密度组(P<0.01),高密度组虹鳟血清中蛋白浓度极显著低于中、低密度组(P<0.01),低密度组超氧化物歧化酶活力极显著高于中、高密度组(P<0.01)。第44天,高密度组虹鳟谷草转氨酶活力显著高于低密度组(P<0.05)。当养殖密度为高密度(35.48±4.79)kg/m^(3)时会对虹鳟的生理造成严重的负面影响。

The purpose of this experiment was to investigate the differences in physiological and biochemical indices of rainbow trout under different stocking densities,and to provide a reference for determining the appropriate density of rainbow trout for recirculating water culture.The 600 healthy rainbow trout with similar body condition were randomly divided into three experimental groups:low density group(100),medium density group(200)and high density group(300),and the growth and physiological and biochemical indexes were measured on day 1,day 23 and day 44,respectively.The final body mass,weight gain rate and specific growth rate of rainbow trout in the medium-density group were significantly higher than those in the high-density group(P<0.05).On day 1,the number of leukocytes in the high and low density groups was extremely significantly higher than that in the medium density group(P<0.01),and the lactate dehydrogenase activity of rainbow trout in the high density group was extremely significantly higher than that in the medium and low density groups(P<0.01).On days 23 and 44,the number of leukocytes,erythrocytes,ghrelin activity and total bilirubin content in the high-density group were significantly higher than those in the medium and low-density groups(P<0.01),the peroxidase activity in the high-density group was significantly lower than that in the medium-density group(P<0.01),the protein concentration in the serum of rainbow trout in the high-density group was significantly lower than that in the medium and low-density groups(P<0.01),and the superoxide dismutase activity in the low-density group was significantly higher than that in the medium and low-density groups(P<0.01).Superoxide dismutase activity was significantly higher in the low-density group than in the medium-and high-density groups(P<0.01).On day 44,the glutathione transaminase activity of rainbow trout in the high-density group was significantly higher than that in the low-density group(P<0.05).When the culture density was high density(35.48±4.79)kg/m^(3),it would cause serious negative effects on the physiology of rainbow trout.