瓯江彩鲤仔鱼摄食与生长研究

Studies on growth and feeding of the yolk-sac larvae of Cyprinus carpio var. color

对瓯江彩鲤卵黄囊期仔鱼的发育进行了连续观察,研究其在开口摄食前的发育、生长以及初次摄食饥饿不可逆点(PNR)。结果表明:(1)仔鱼对卵黄囊的日净消耗量的最大值出现在出膜后的第1d,体长最大增长率出现在3日龄仔鱼;(2)孵化后第7d即6日龄仔鱼,卵黄囊基本全部被吸收,同时,饥饿期仔鱼开始出现负生长;(3)3日龄仔鱼开始摄食,5日龄仔鱼初次摄食率达84.38%,8日龄仔鱼降到41.94%,进入PNR,从刚孵化到仔鱼初次摄食饥饿"不可逆点"的时距达9d;(4)仔鱼混合营养期较短,为3d,摄食能力时间可持续8d。

The development of the yolk-sac larvaeof Cyprinus carpio var. color in the period of starvation were observed and the point of no return（ PNR） was also studied. The results showed that：（1） After hatching, the highest yolk-sac consuming rate happened on the first day, while the highest growth rate of total length of larvae occurred on the third day;（2） On the sixth day after hatching, the yolk-sac was absorbed completely, from then the starved larvae decreased in total length;（3）After hatching, the larvae started to feed on the third day with low initial feeding rate, the initial feeding rate reached the highest figure 84.38% on the fifth day, and then decreased to 41.94% on the eigth day, while the larvae reached the point of no return;（4） Larval period of mixed nutrition was 3 days, feeding ability time was 8 days.