探讨饥饿胁迫对似鱼句早期仔鱼开口摄食及生长的影响,确定初次摄食期和饥饿不可逆点(Point of no return,PNR),为其人工育苗提供技术支撑。采用实验生态学方法,观测了饥饿对早期仔鱼卵黄囊吸收、形态、行为、生长、存活及初次摄食率的变...探讨饥饿胁迫对似鱼句早期仔鱼开口摄食及生长的影响,确定初次摄食期和饥饿不可逆点(Point of no return,PNR),为其人工育苗提供技术支撑。采用实验生态学方法,观测了饥饿对早期仔鱼卵黄囊吸收、形态、行为、生长、存活及初次摄食率的变化,并确定其PNR和初次投喂最佳时间。结果显示,在水温(25.5±1.2)℃的条件下,似鱼句仔鱼4日龄开口摄食,5日龄卵黄消耗殆尽,混合营养期仅1 d,5、6日龄初次摄食率达到峰值(100%),8~9日龄到达PNR,从开口摄食到PNR的时间为4~5 d,50%累计死亡率时间与PNR出现在同一天;在饥饿状态下,体质量在6日龄后出现负增长,而全长在9日龄后出现负增长,相对肥满度不断下降,且极显著低于对照组(P<0.01),可作为判别似鱼句饥饿仔鱼的重要依据。结果表明,似鱼句属于混合营养期相对较短的鱼类,其仔鱼耐受饥饿的能力较差;在水温(25.5±1.2)℃的条件下,人工繁育似鱼句仔鱼可在4日龄开始投喂,初次投喂最佳时间为5日龄,但初次投喂最迟不宜超过7日龄。展开更多
以黑鲷(Acanthopagrus schlegelii♀)×真鲷(Pagrus major♂)杂交子一代为亲鱼,于2017年4月在水温(21.8±0.4)℃条件下,对自然受精、人工孵化获得的杂交子二代(F_2)早期仔鱼进行发育观察,并就饥饿对仔鱼早期生长与存活的影响及...以黑鲷(Acanthopagrus schlegelii♀)×真鲷(Pagrus major♂)杂交子一代为亲鱼,于2017年4月在水温(21.8±0.4)℃条件下,对自然受精、人工孵化获得的杂交子二代(F_2)早期仔鱼进行发育观察,并就饥饿对仔鱼早期生长与存活的影响及不可逆点(point of no return,PNR)进行研究。结果表明,杂交F_2初孵仔鱼全长(2.40±0.15)mm,仔鱼3日龄开口摄食,混合营养期4~5 d,7日龄全长增长到(3.95±0.04)mm,生长态势正常;杂交F_2仔鱼开始摄食的初次摄食率及最高摄食率分别为45.8%及77.21%,6日龄时初次摄食率下降为29.83%,抵达PNR时间;饥饿仔鱼5日龄时负生长,全长与对照组有显著差异(P<0.05),6日龄时全长与对照组有极显著差异(P<0.01)。研究表明杂交F2早期仔鱼具有较好的生长态势;其开始投饵的最适时机应于仔鱼开口后的3 d内。展开更多
[Objective] The paper was to study the growth and development of Onychostoma sima in postembryonic development stage. [Method] The oosperm was obtained by artificial spawning and artificial insemination method, and ha...[Objective] The paper was to study the growth and development of Onychostoma sima in postembryonic development stage. [Method] The oosperm was obtained by artificial spawning and artificial insemination method, and hatched under laboratory condition. The indexes such as body weight, body length, length in front of anus and body height were measured to establish larvae growth model. [Result] When the water temperature was （20±1.5） ℃, the body length and body weight of newly hatched larvae were （10.28±0.05） mm and （7.79±0.08） mg, respectively. O. sima larvae begin to feed on the 4 th day after hatching, the initial feeding rate was 48%, the highest feeding rate was 100% on the 6 th d. The-point-of-no-return （PNR） was 13.5 d. In addition, it was also observed that the appearance time of PNR point of O. sima larvae was close to death time of completely starved group, being only 2 d, indicating that once O. sima larvae reached the PNR point, they would face death threats within short time. Therefore, various growth conditions for O. sima larvae should be satisfied to ensure full development of all organs, thereby reducing death and growth stagnation caused by adverse environment in early postembryonic stage. [Conclusion] The study provided theoretical basis for solving the problems in artificial breeding.展开更多
文摘探讨饥饿胁迫对似鱼句早期仔鱼开口摄食及生长的影响,确定初次摄食期和饥饿不可逆点(Point of no return,PNR),为其人工育苗提供技术支撑。采用实验生态学方法,观测了饥饿对早期仔鱼卵黄囊吸收、形态、行为、生长、存活及初次摄食率的变化,并确定其PNR和初次投喂最佳时间。结果显示,在水温(25.5±1.2)℃的条件下,似鱼句仔鱼4日龄开口摄食,5日龄卵黄消耗殆尽,混合营养期仅1 d,5、6日龄初次摄食率达到峰值(100%),8~9日龄到达PNR,从开口摄食到PNR的时间为4~5 d,50%累计死亡率时间与PNR出现在同一天;在饥饿状态下,体质量在6日龄后出现负增长,而全长在9日龄后出现负增长,相对肥满度不断下降,且极显著低于对照组(P<0.01),可作为判别似鱼句饥饿仔鱼的重要依据。结果表明,似鱼句属于混合营养期相对较短的鱼类,其仔鱼耐受饥饿的能力较差;在水温(25.5±1.2)℃的条件下,人工繁育似鱼句仔鱼可在4日龄开始投喂,初次投喂最佳时间为5日龄,但初次投喂最迟不宜超过7日龄。
文摘以黑鲷(Acanthopagrus schlegelii♀)×真鲷(Pagrus major♂)杂交子一代为亲鱼,于2017年4月在水温(21.8±0.4)℃条件下,对自然受精、人工孵化获得的杂交子二代(F_2)早期仔鱼进行发育观察,并就饥饿对仔鱼早期生长与存活的影响及不可逆点(point of no return,PNR)进行研究。结果表明,杂交F_2初孵仔鱼全长(2.40±0.15)mm,仔鱼3日龄开口摄食,混合营养期4~5 d,7日龄全长增长到(3.95±0.04)mm,生长态势正常;杂交F_2仔鱼开始摄食的初次摄食率及最高摄食率分别为45.8%及77.21%,6日龄时初次摄食率下降为29.83%,抵达PNR时间;饥饿仔鱼5日龄时负生长,全长与对照组有显著差异(P<0.05),6日龄时全长与对照组有极显著差异(P<0.01)。研究表明杂交F2早期仔鱼具有较好的生长态势;其开始投饵的最适时机应于仔鱼开口后的3 d内。
基金Supported by Special Funds for Breeding Research of Sichuan Provincial Department of Finance(2006YZGG08-002)~~
文摘[Objective] The paper was to study the growth and development of Onychostoma sima in postembryonic development stage. [Method] The oosperm was obtained by artificial spawning and artificial insemination method, and hatched under laboratory condition. The indexes such as body weight, body length, length in front of anus and body height were measured to establish larvae growth model. [Result] When the water temperature was （20±1.5） ℃, the body length and body weight of newly hatched larvae were （10.28±0.05） mm and （7.79±0.08） mg, respectively. O. sima larvae begin to feed on the 4 th day after hatching, the initial feeding rate was 48%, the highest feeding rate was 100% on the 6 th d. The-point-of-no-return （PNR） was 13.5 d. In addition, it was also observed that the appearance time of PNR point of O. sima larvae was close to death time of completely starved group, being only 2 d, indicating that once O. sima larvae reached the PNR point, they would face death threats within short time. Therefore, various growth conditions for O. sima larvae should be satisfied to ensure full development of all organs, thereby reducing death and growth stagnation caused by adverse environment in early postembryonic stage. [Conclusion] The study provided theoretical basis for solving the problems in artificial breeding.
