【作者】 陈国柱； 方展强； 马广智；

【Author】 CHAN Guo-zhu FANG Zhan-qiang MA Guang-zhi (College of Life Sciences,South China Normal University,Guangzhou 510631,China)

【机构】 华南师范大学生命科学学院；

【摘要】 对唐鱼卵黄囊期仔鱼在早期发育和饥饿期的摄食能力和生长作了观察。结果表明:①孵化后第3d仔鱼初次摄食,卵黄容量从初孵时的0.0589mm³降到0.0057mm³,眼、口、肠管、肛门和胸鳍等器官的功能基本形成,巡游模式建立:孵化后第5d卵黄囊消耗尽,混合营养期仅2 d;不能建立外源营养的仔鱼在孵化后第9-10 d进入PNR期,并出现胸角。PNR后1-2 d内仔鱼全部死亡。体长和卵黄容积的关系回归分析方程为:L_■=-0.0494x_?3+0.1999。卵黄囊容积和日龄的关系回归分析方程为:V_■=-0.016d+0.0741。②仔鱼在不同饥饿阶段初次摄食率变化曲线是:开始较低,随即上升,高峰出现在开口摄食后的第2d,达到100%,并持续4-6 d。孵化后第9-10 d,初次摄食率低于50%,抵达PNR。死亡率在进入PNR点后1-2 d内激增到100%。摄食强度达到最高时的时间则相应延迟,在开口摄食的第3d达到最高峰。开口摄食的第8 d摄食率为0。③仔鱼初孵期的生长率平均为0.430mm/d,进入摄食期后,饥饿仔鱼体长仍有缓慢增长,平均为0.05 mm/d,同期摄食仔鱼生长率也下降,平均增长量为0.244 mm/d;饥饿仔鱼卵黄消失后的第2-3 d停止增长,PNR前后体长出现负增长,摄食仔鱼PNR期的平均增长量为0.385 mm/d。建立外源性营养的仔鱼在孵化后15 d内,其体长增长和日龄的回归分析方程为:L_■=0.2786d+2.4837。不能建立外源性营养的仔鱼在存活期间其体长增长和日龄的相关方程式为L_■=0.4833Ln（d）+2.8355。④孵出后的15 d发育期内,延迟投喂1d对唐鱼仔鱼的生长产生显著影响,延迟2 d仔鱼进行了完全恢复性生长,与不延迟仔鱼的生长无显著差异;延迟3-6 d对仔鱼生长产生极显著的影响,严重影响生长品质和存活率;延迟7 d以上导致仔鱼最终全部死亡。更多还原

【Abstract】 The yolk-sac larvae of Tanichthys albonubs were reared from March to June 2004 to exam the changes in feeding ability and growth during early development and starvation.The results showed that:①eyes,mouth,digestive tracts,anus and the pectoral fins in 3-day larvae became functional,and the cruising swimming was formed.Larvae began to have the feeding ability.The yolk was absorbed largely, and the volume had been changed from 0.0589mm³ to 0.0057mm³.Yolk was absorbed completely in S-day unfed larvae,wh/ch began to suffer starvation.The equation relating growth in length（L）to the volume of yolk.sac in days（d）over 5-days post-hatching for the unfed larvae was L_（mm）=-0.0494x₍（mm3）+ 0.1999.The equation relating the volume of yolk-sac to age in days（d）over 5-day period post-hatching for the fed larvae was V_（mm3）=-0.016d+0.0741.②The initial feeding rate in 3-day larvae were up to 33.3-66.7%.4-day unfed larvae reached the highest initial feeding rate,up to 100%,and this highest initial feeding rate lasted for 4-6 days.After hatching 9-10 days,the initial feeding rate of the unfed larvae was lower than 50%,which was the point-of-no-return（PNR）.After passing the PNR,starved larvae not only entered a negative growth phase,but also showed a decrease in size of various organs,and the pectoral girdle projected markedly and formed the pectoral angle.After hatching 11-12 days later,all unfed larvae died.The characteristic of changing of feeding intensity was similar with the initial feeding rates.0 to 2 day larvae didn’t had the feeding ability yet.3-day larvae could prey paramecium,Paramoecium caudatum only 7.7.5-day larvae reached the highest feeding intensity,which preyed the paramecium,up to 49.4,and then declined.After hatching 10 days,feeding intensity became 0.Feeding ability of larvae were deprived by the starvation.③The mean growth rate was 0.430mm/d for larvae living on yolk（0-3 d）and 0.05mm/d when the larvae reach the external feeding stage but no food was available（3-9 d）.When fed on paramecium the mean growth rate was 0.244mm/d for the larvae during the feeding stage（3-9 d）.The equation relating growth in length（L）to age in days（d）over 15-day period post-hatching for the fed larvae was L_（mm）=0.2786d+2.4837.The equation relating growth in length（L）to age in days（d）total 11-days they could live post-hatching for the unfed larvae was L_（mm）=0.4833Ln（d）+2.8355.④Over the 15-days after hatching,delayed feeding 1 day could effect the growth rates of larvae remarkably.Delayed feeding 2 d,the larvae processed the completely compensatory growth,and the total length was not remarkable between the 0 and 2 d delaying feeding larvae.Delayed feeding 3-6 d could effect the growth and survival rate of larvae very remarkably.Delayed feeding 7d,all the larvae died eventually despite they could live for a short time yet.更多还原