摘要
【目的】全面掌握鲈鲤仔鱼早期培育过程的摄食特点和饥饿耐受力,为其苗种规模化培育提供技术支撑。【方法】在18.5~21.9℃水温条件下,利用人工繁殖孵化获得的鲈鲤初孵仔鱼进行饥饿试验,研究饥饿胁迫对鲈鲤仔鱼生长、发育、存活、卵黄囊吸收、摄食率及摄食强度的影响,并确定鲈鲤仔鱼的不可逆生长点(PNR)。【结果】饥饿对鲈鲤仔鱼全长、体长、体高及肛前长等生长指标有极显著影响(P<0.01,下同),对眼径和鳔等组织器官发育也有明显影响。鲈鲤仔鱼5日龄开口摄食,进入混合营养期,10日龄时仔鱼卵黄囊基本消耗殆尽,鲈鲤仔鱼混合营养期维持5 d。鲈鲤仔鱼5日龄开始摄食外源性营养,初次摄食率约20%,随后逐步提高,至13日龄时达最高值(100%),之后开始下降,在17日龄时下降至40%,低于最大初次摄食率的50%。根据PNR定义,即17日龄是鲈鲤仔鱼的PNR。在5~11日龄期间(饥饿7 d内),鲈鲤仔鱼的初次摄食强度和摄食能力随着饥饿天数的增加呈上升趋势,12日龄后(饥饿7 d以上)则随着饥饿天数的增加呈迅速下降趋势。饥饿组仔鱼的累计死亡率在17日龄(饥饿13 d)时剧增,到18日龄(饥饿14 d)时其累计死亡率达88.00%,而摄食组仔鱼的累计死亡率仅为14.75%;至19日龄(饥饿15 d)时饥饿组仔鱼的累计死亡率高达100.00%,摄食组仔鱼的累计死亡率仍为14.75%。饥饿组鲈鲤仔鱼的50.00%累计死亡率出现日龄为18日龄,即在PNR出现之后。【结论】在18.5~21.9℃水温条件下,鲈鲤仔鱼混合营养期为5 d,PNR发生在17日龄。鲈鲤仔鱼可在5日龄后开始投喂,最佳投喂时间为8日龄,但最晚投喂时间不宜超过13日龄。
【Objective】To study the feeding characteristicsandstarvation tolerance of Percocypris pingi during the early development of larvae,and provide technical support for the large-scale breeding of larvae.【Method】Under the condition of water temperature of 18.5-21.9℃,the experimental ecology method was used to conduct starvation experiments on the newly hatched larvae obtained by artificial breeding and hatching.Analyze and study the effects of starvation stress on the growth,development,survival,yolk sac absorption,feeding rate and feeding intensity of larvae,and initially determine the point of no return(PNR)of larvae.【Result】The growth index of the full length,body length,body height and anal length of the larvae of P.pingi had extremely significant effect(P<0.01,the same below),and had obvious effects on the development of tissues and organs such as eye diameter and sputum.The larvae of P.pingi were fed at 5 d of age and entered the mixed nutrition period.At 10 d of age,the yolk sac of the larvae was basically consumed,and the mixed nutrition period for larvae of P.pingi were 5 d.The larvae of P.pingi began to eat exogenous nutrition at the age of 5 d.The initial feeding rate was about 20%,and then the initial feeding rate gradually increased.The initial feeding rate of the 13-dayold larvae reached the highest value of 100%.Then,the initial feeding rate began to decline.By the 17 d of age,the initial feeding rate dropped to 40%,which was lower than 50%of the maximum initial feeding rate.According to the definition of PNR,the 17 d of age was PNR for larvae of P.pingi.The larvae of P.pingi initial feeding intensity and feeding ability increased with the increase of starvation days during 5-11 d of age(starved within 7 d).After 12 d of age(starved over 7 d),the initial feeding intensity and feeding ability of larvae decreased rapidly with the increase of hunger days.The cumulative mortality rate of starved group increased sharply on 17 days old(starved for 13 d).When the starved group was 18 days old(starved for 14 d),the cumulative mortality rate reached 88.00%,and the cumulative mortality rate of the larvae in the feeding group was 14.75%.At 19 d of age,the cumulative mortality rate of the hunger fish in the starved group was 100.00%,while the cumulative mortality rate of the larvae in the feeding group was 14.75%.50.00%cumulative mortality of larvae in the hunger-stricken fish in starved group was 18 days old,after PNR.【Conclusion】Under the condition of water temperature of 18.5-21.9℃,the mixed nutrition period for larvae of P.pingi were 5 d,and PNR occurs at 17 d of age.Larvae of P.pingi can be fed after 5 d of age.The best feeding time is 8 d of age,but the latest feeding time should not exceed 13 d of age.
作者
张建明
姚金忠
姜伟
郭文涛
ZHANG Jian-ming;YAO Jin-zhong;JIANG Wei;GUO Wen-tao(Institute of Chinese Sturgeon Research,China Three Gorges Project Corporation,Yichang,Hubei 443100,China;Hubei Key Laboratory of Three Gorges Project for Conservation of Fishes,Yichang,Hubei 443100,China;China Three Gorges Corporation Operation and Administration Center for River Basin Hydro Complex,Yichang,Hubei 443100,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2020年第10期2565-2572,共8页
Journal of Southern Agriculture
基金
国家重点研发计划项目(2016YFC0502210)
国家自然科学基金项目(51779016)
中国长江三峡集团有限公司科技计划项目(ZHX2017025,JG/18001B)。
关键词
鲈鲤
仔鱼
饥饿
摄食率
摄食强度
不可逆生长点(PNR)
Percocypris pingi
larvae
starvation
feeding rate
feeding intensity
point of no return(PNR)
