The Effects of Starvation on Feeding,Survival,Growth and Development of Spinibarbus sinensis Larvae

Under the laboratory condition Spinibarbus sinensis larvae were reared at water temperature (25.0±0.5)℃ to examine the effects of starvation on the feeding,survival,growth and development under the starvation condition.The results showed that the larvae had the first feeding ability 5 days after hatching and the initial feeding rate was 86.7%,the unfed larvae had the highest feeding rate at 100% at the age of 6-11 days after hatching and followed by decreasing rate,and unfed larvae reached the point of no return(PNR)18 days after hatching.The survival rate was not affected when delayed initial feeding for 1-6 days,and then decreased with increasing of delay of initial feeding time(P0.05).Under the absolutely hungry condition,the time of above 50% mortality and 100% mortality for the starvation larvae happened at the age of 19 days and 22 days after hatching respectively.When delayed initial feeding for 6,7,5,3,4 days,there were significant differences in growth rate of the total length,head length,eye diameter,body heigth and caudal peduncle height between treatments and controls respectively(P0.05).The unfed larvae had bigger head and thinner body,curved spina dorsalis,atrophy of intestines etc,and also pectoral angle when starved for over 7 days,starvation prevented the development of all fins of the unfed larvae.Therefore,it is suggested that the most suitable first feeding time of Spinibarbus sinensis larvae should be within 6～8 days after hatching.