摘要
在实验室条件下,采用观察、测量记录外部形态特征等方法研究了饥饿胁迫下白甲鱼(Onychostoma sima)仔鱼的摄食、生长、形态和存活的变化。结果显示:在水温(20±1.5)℃时,饥饿组和投喂组白甲鱼仔鱼在孵化后第4天开始摄食,初次摄食率为48%,第6天初次摄食比率达到100%。饥饿组仔鱼抵达饥饿不可逆点(PNR)的时间为13.5 d,50%累计死亡率出现时间基本上与PNR出现时间相同(13.5 d),表明第13.5天为白甲鱼早期发育中较为敏感的阶段。试验期间,饥饿仔鱼体重、体长、眼间距和体高分别在第6、7、11和12天后均显著低于对照组(P<0.05)。试验结束(16 d)时饥饿组仔鱼体重、体长和眼径的瞬时增长率均显著低于摄食组(P<0.05),而头长、体高和眼间距差异不显著(P>0.05)。结果表明饥饿对仔鱼生长发育起延迟作用,混合营养期延迟投喂,仔鱼生长发育水平明显低于正常投喂仔鱼。
Studies were conducted to examine the effects of starvation on feeding, growth, morphological development and survival of Onychostoma sima （20 ± 1.5 ）℃ on laboratory conditions. All larvae were divided into 3 groups： feeding group, unfed group and mortality observation group, each group was reared in three 11.5 L bowls. Every day 10 larvae were taken from the culture aquarium of unfed or feeding group to measure the morphological indexes, while 10 larvae were taken to examine feeding ratio and intensity. The dead larvae of mortality observation group were recorded and removed every day. The results showed that： the larvae in the feeding group and unfed group had feeding ability first time on 4th d after hatching; the initial feeding rate was 48% , the highest feeding rate was 100% on the 6th d. The yolk exhausted 8 - 10 d after hatching. While the unfed larvae had feeding ratio at 100% when re-fed from 6 d to 11 d following by decreasing rate; On the 11 th d, feeding ratio of unfed larvae decreased compared with those of feeding larvae, and it was 0 on the 16th d. The-point-of-no-return （PNR） was 13.5 day of unfed larvae. At the same time, the unfed group had 50%, which indicated that the 13.5 d larvae stage is more sensitive to starvation in the early life stage. During the experiment, the weight, standard length, eye distance and body depth in unfed group were significantly lower than that of feeding group on the 6th d, 7th d, 11th d and 12th d respectively （P 〈0. 05）. At the 16 day after hatching, the different part of the body had different growth rate. Compared with the feeding larvae at the same time, the unfed larvae grew very slowly. The weight, standard length and eye diameter were significantly lower than feeding group （P 〈 0. 05）. It can be concluded that starvation can delay the larvae＇s growth and development. The level of the growth and development in unfed larvae will be lower than feeding larvae＇ if there have no food in mixed feeding stage.
出处
《淡水渔业》
CSCD
北大核心
2009年第5期32-37,共6页
Freshwater Fisheries
基金
四川省财政育种攻关专项资金项目(2006YZGG08-002)
