饥饿不同时间后投喂对许氏平鮋生长及体成分的影响

Effects of Starvation for Various Days and Re-feeding on Growth and Body Compositions in Rockfish Sebastes schlegeli

在室内水温21.8~25℃条件下,将初始体质量为(8.87±0.16)g的许氏平鮋Sebastes schlegeli放养在50cm×50cm×100cm网箱中,饥饿0(S0)、3(S3)、6(S6)、9(S9)和12d(S12)后分别投喂30d、27d、24d、21d和18d,每组3个重复,测定其体质量、肥满度、脏体指数、肝体指数、摄食率、食物转化率及全鱼和肝脏主要生化组成的变化。结果表明:随着饥饿时间的延长,幼鱼体质量逐渐降低,各饥饿组鱼体质量显著低于同期对照组(P<0.05)。恢复投喂后,S3组体质量、增重率(WGR)和特定生长率(SGR)显著高于对照组S0(P<0.05),S6与S0组无显著差异(P>0.05),而S9与S12组未能达到S0水平(P<0.05)。S3组食物转化率(FCE)显著高于其余各组(P<0.05),S9、S12组则显著低于对照组(P<0.05)。饥饿状态下,各饥饿组鱼肝体指数与脏体指数显著小于S0组(P<0.05));恢复投喂后各组肝体指数、脏体指数与对照组无显著差异。随着饥饿时间的延长,鱼体粗灰分含量显著升高(P<0.05),水分与粗蛋白含量呈上升趋势(P>0.05)。饥饿6d后,鱼体粗脂肪含量显著低于对照组,饥饿12d时粗脂肪含量比饥饿前降低了19.33%(P<0.05)。恢复投喂后,各试验组间鱼体水分、粗蛋白、粗脂肪和粗灰分含量差异不显著(P>0.05)。S9和S12组中肝脏粗脂肪含量显著低于S0组(P<0.05)。

Juvenile rockfish Sebastes schlegeli with initial body weight of （ 8.87±0.16） g were cultured in a 50 cm×50 cm× 100 cm cage, starved for 0 （S0）, 3 （S3）, 6 （S6）, 9 （$9）, and 12 （S12） d and refed for 27 d, 24 d, 21 d, and 18 d at water temperature of 21.8-25 ℃ to investigate the effects of starvation and subsequent re-feeding on body weight, hepatosomatic index （HSI）, visceroso- matic index （VSI）, feeding rate, food conversion efficiency, and main biochemical composition in whole body and liver in rockfish ju- veniles cultured in cages at water temperature of 21.8-25 ℃. The body weight, condition factor （CF）, viscerosomatic index （VSI）, hepatosomatic index （HSI）, food intake, food conversion efficiency, and approximate compositions in whole fish and live. The results showed that the starved fish had decrease in body weight gradually as elapse of starvation period, significantly lower that the fish in group SO （P〈0.05）. After re-feeding, there were significantly higher weight gain rate and specific growth rate in group S3 than in SO （P〈0.05）, without significant difference between S6 and SO （P〉0.05）, and significantly lower in groups S9 and S12 than in group S0 （P〈0.05）. Duration of starvation, the HSI and VSI in SO were higher than those in other groups （P〈0.05）, without significant differ- ence in each group after re-feeding. The condition factor in the fish was affected by starvation and re-feeding （P〉0.05）. The ash con- tent in the whole body was found to be significant high as the increase in starvation period （P〈0.05）. There was significant lower body lipid in the fish in other groups than in the fish in group SO starved for 6 days （P〈0.05）. There were no significant differences in mois- ture, protein, lipid and ash contents in the whole fish body in each group after re-feeding （P〉0.05）. However, the fish had significant lower lipid in liver in groups S9 and S12 than the fish in groups SO and S3 did （P〈0.05）.