超声波对尼罗罗非鱼幼鱼生长的影响

The effect of ultrasonic wave on growth in Nile tilapia

选择尼罗罗非鱼Tilapia nilotica幼鱼(平均体重为1.95 g±0.60 g)为试验对象,用3种不同强度的超声波对其进行辐射刺激,共设3个试验组和1个对照组。经过60 d的超声波辐射养殖,结果表明:各组间体重存在极显著性差异(P【0.01),其中每天受频率为23 kHz、声源声强为200 mW/cm2的连续超声波辐射刺激5 min的试验组鱼,其体重最高,比对照组鱼体重增长约7.58%;但每天受频率为23 kHz、声源声强为600 mW/cm2的连续超声波辐射刺激5 min的鱼体,其体重反而比对照组体重减少约5.80%。各试验组尼罗罗非鱼体重与胃蛋白酶活性之间没有明显关系。当环境声强为1.58~1.60 mW/cm2时,对尼罗罗非鱼幼鱼生长比较有利。

The Nile tilapia(Oreochromis niloticus) juveniles weighing(1.95±0.60)g held in tanks of each 1.2 m × 0.7 m × 0.7 m were exposed to 3 levels of ultrasonic waves(23 kHz,acoustic intensity of 200 mW/cm2,and 5 min,group A;23 kHz,acoustic intensity of 400 mW/cm2,and 5 min,group B;23 kHz,acoustic intensity of 600 mW/cm2,and 5 min,group C;and 0 kHz,acoustic intensity of 0 mW/cm2,and 0 min,Group D)to evaluate the effect of ultrasonic wave on growth of the fish with triplication at water temperature of 27.0 ℃ for 60 days.The results showed that the fish in group A had the maximal specific growth rate(SGR) in body weight,7.58% higher than that in group D(P<0.01).However,there was 5.80% less in SGR in the fish in group C than that in group D.There was no significant relationship between the SGR and the protease activity in the stomach.The good growth was found at the acoustic intensity of 1.58-1.60 mW/cm2.