摘要
【目的】确定黄鳝(Monopterus albus)的初次摄食期和不可逆点(PNR),为提高人工繁育黄鳝苗成活率和饵料利用率提供理论依据。【方法】对刚出膜黄鳝仔鱼分别进行饥饿试验和正常投喂试验,观察卵黄囊吸收、仔鱼生长及初次摄食率的变化,分析饥饿对仔鱼生长、形态和行为的影响,确定其不可逆点。【结果】在25～28℃的水温条件下,黄鳝仔鱼于5日龄(出膜后第6d)开始向外界摄食,8日龄卵黄囊吸收殆尽,5～8日龄为混合营养阶段,9日龄摄食率达到峰值(96%),16日龄进入饥饿期;在饥饿状态下,8日龄仔鱼体长达最大值(3.20±0.0760cm),此后略有下降但基本保持稳定,仔鱼体重于7日龄达最大值(0.0205±0.0533g),此后不断下降;饥饿仔鱼的肥满度一直呈下降趋势,进入不可逆期后体色逐渐发黑,身体呈非正常扭曲,摄食能力极大降低,外界干扰时出现颤抖、打转现象直至死亡。【结论】在25～28℃的水温条件下,黄鳝仔鱼的最佳投喂时机在8日龄,16日龄抵达不可逆点。
Objective The initial feeding time and point of no return （PNR） for the larvae of Monopterus albus were determined to provide references for improving survival rate of artificial eel seedling and bait utilization rate. Method The comparative experiment on starvation and normal feeding of larvae was carried out to investigate the effects of starvation on feeding. Through observing absorption of yolk sac, the growth of larvae and the change of initial feeding rate, the PNR was determined. ResultAt the water temperature of 25-28℃, the larvae started to search for food on the 6th day. The volume of yolk sac vanished on the 9th day. The feeding rate reached the maximum rate of 96% on the 10th day. The PNR appeared on the 17th day. It also showed that under starvation, the total length of larvae reached a maximum （3.20±0.0760 cm） on the 9th day. Afterwards its length decreased slightly and kept stable. However, the weight of larvae reached a maximum （0.0205±0.0533 g） on the 8th day and decreased constantly. The body fatness displayed a downside trend all the way. At the PNR, its body color gradually turned dark. Its body improperly deformed. It would tremble, turn over and even die under disturbance. Conclusion At the water temperature of 25-28℃, the best feeding time was on the 9th day, and the PNR arrived on the 16 th day.
出处
《南方农业学报》
CAS
CSCD
北大核心
2013年第6期1036-1040,共5页
Journal of Southern Agriculture
基金
农业部行业(农业)科研专项项目(201003076)
安徽省科技攻关项目(12010302056)
安徽省农业科学院院长青年创新基金项目(12B0516)
安徽省农业科学院黄鳝创新团队科研计划项目(12c0501)
关键词
黄鳝仔鱼
饥饿
不可逆点
摄食率
肥满度
Monopterus albus larvae
starvation
point of no return（PNR）
feeding rate
fatness
