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

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.