受短期饥饿胁迫下麦瑞加拉鲮鱼(Cirrhina mrigola)幼鱼的生长、肌体组分及其内脏消化酶活力的变化特征

DEVELOPMENT,BIOCHEMICAL COMPOSITION AND DIGESTIVE ENZYME ACTIVITY OF JUVENILE CIRRHINA MRIGALA UNDER SHORT-TERM STARVATION

以麦瑞加拉鲮鱼幼鱼为实验动物,进行短期饥饿对其生长、肌体组分及内脏消化酶活力的影响实验。结果表明,随着饥饿时间的延长,麦瑞加拉鲮鱼幼鱼各生长参数观测值,体内粗脂肪、碳水化合物和粗蛋白的含量以及能值均逐渐减小或减少;实验期间体内各组分的同期相对损失率以粗脂肪和碳水化合物为最高,且粗脂肪降幅高峰的出现时段总早于碳水化合物,而粗蛋白的消耗量和损失率则一直处于较低的水平。淀粉酶活力的损失量均高于同期其他消化酶,蛋白酶活力在13—16天间出现反弹现象,其第16天的酶活力值与实验起始值相当。

Demanded from fish farming for improving culture efficiency and optimize the profit, the authors carried out a 16-day starvation experiment between July and August 2005 on juvenile Cirrhina mrigala collected in a seedling farm near Yuyao, Zhejiang, for determining the changes in body development, biochemical composition and digestive enzyme activity of the animal. The samples were （5.38 ± 0.40）cm in body length, body weight at （2.58 ±0.51 ）g. They had been acclimated in lab for 7 days. Natural sea water was used as the experimental water after 48h-exposure to the air. The experimental fish were raised in foamed plastic boxes sized 40 × 50 × 60cm^3. The experiment was conditioned at （27.5 ±2.5 ） ℃ in water temperature and pH at 7.0 ±0.2. Five data-reading stages were set in the experiment at Days 0, 4, 8, 12, and 16 respectively for observing and recording the parameters, including body length, body weights in wet and dry, and water and ash weight; the biochemical ones of crude protein, crude fat, carbohydrate and energy value; and those of digestive enzyme activity such as proteinase, lipase, and amylase. The results showed that the growth, energy value, the contents of the crude fat and crude protein decreased with the starvation time. In terms of relative total lost amount, crude fat and carbohydrate were greater than crude protein, and the peak of crude fat decrease appeared earlier than that of carbohydrate. The consumption and lost amount of crude protein were in lower level. During the experiment, the activity of amylase reduction was higher than that of other digestive enzymes, while the proteinase activity increased significantly during Day 13 to Day 16 and the activity value at Day 16 equaled to that in Day 1. The authors defined the time or period when starvation effect was most prominent for the experimental fish as significant-starvation-point or significant-starvation-period, respectively.