短期饥饿胁迫对花羔红点鲑生长率和耗氧率的影响

Effects of Short-time Starvation Stress on Growth Rate and Oxygen Consumption Rate of Salevlinus malma

在室外自然条件下（2~8℃）,将初始平均体质量（275.5±33.9）g的花羔红点鲑饥饿处理0（对照组）,5,10,15,20 d,再投喂饵料,然后再饱食15 d,研究短期饥饿胁迫对花羔红点鲑生长率和耗氧率的影响。结果表明：饥饿和再投喂对花羔红点鲑的生长有显著影响。随饥饿时间延长,花羔红点鲑的体质量不断下降,体质量损失率逐渐加大,各处理组（0,5,10,15,20 d）体质量损失率分别为0,3.59%,7.06%,7.61%,9.92%。花羔红点鲑在继饥饿后再投喂,其体质量逐渐增加,体质量增长率随饥饿时间延长不断增加。各处理组（0,5,10,15,20 d）体质量增长率分别为5.25%,11.10%,12.81%,17.93%,19.13%。花羔红点鲑继饥饿后再投喂,通过对各处理组特定生长率（SGR）、摄食率（FR）和饲料效率（FCE）的研究结果表明：饥饿5 d,10 d组的特定生长率要高于对照组（0 d）,但差异不显著（P〉0.05）,15 d,20 d组的特定生长率显著高于对照组（P〈0.05）。饥饿5 d组摄食率升高,与对照组相比差异显著（P〈0.05）,10 d,20 d的摄食率与对照组相比差异不显著（P〉0.05）,而15 d组的摄食率下降,与对照组相比差异显著（P〈0.05）。随饥饿时间延长,各处理组饲料效率不断升高,与对照组相比差异显著（P〈0.05）。饥饿和再投喂对花羔红点鲑耗氧率影响显著。花羔红点鲑的代谢率（耗氧率）出现阶段性变化,在饥饿状态下,前期（0~10 d）耗氧率下降速度较快,由217.7 mg/（kg.h）降至157.9 mg/（kg.h）,而后期（10~20 d）下降速度慢,稳定在一定水平上。对照组耗氧率明显要高于饥饿组,其数值在一定范围内波动。再投喂后,花羔红点鲑的代谢率上升,饥饿20 d以内的鱼经过10 d基本恢复到正常水平。

The study on the effects of short-time starvation stress on growth rate and oxygen consumption rate of Salevlinus malma was performed. The experimental fish with initial body mass of （275.5 ± 33.9） g were reared in outdoor cages （ 1.5 m × 2.0 m × 0.7 m） with flowing water supply （ 1.5-2.0 m/s, 2-8 ℃）. Five treatments were designed as 0, 5, 10, 15 and 20 days of starvation period, and the starved fish were refed for 15 days by fresh rainbow trout after certain period of food deprivation treating. Two duplicates were designed and the initial density was 6 fish per cage for each treatment. The body mass growth rate, body mass gain, feeding rate and food conversion ratio were measured after treat-ing by starvation and refeeding respectively. The oxygen consumption was tested every 2 days during the starvation period and every 5 days during refeeding period. The results show that：The starvation and refeeding significantly influenced Salevlinus malma on growth performances and food intake. The body mass losses were significantly higher in 10 d, 15 d and 20 d groups after starving-treatment （ P 〈 0.05）, and no significant difference detected in the 5 d group compared with the control （ P 〉 0. 05）. The body mass gain and specific growth rate （SGR） were considerably higher in 15 d and 20 d groups after refeed-ing-treatment （ P 〈 0.05）, but there were no differences between the control and the 5 d group （ P 〉 0.05）. Compared with the control, significantly higher and lower feeding ratio （FR） was detected in 5 d and 15 d groups respectively during the refeeding period （ P 〈 0.05）, where no significant differences were found in 10 d and 20 d groups （ P 〉 0.05）. Compared with the untreated fish in the control, treat-ed fish in other four groups showed remarkably higher feed conversion efficiency （FCE） during refeeding period （ P 〈 0. 05）. Starvation and refeeding affected oxygen consumption （OC） of Salevlinus malma sig-nificantly. During the first 10 days of starvation, the OC decreased rapidly from 217.7 mg/（kg· h） to 157.9 mg/（kg·h）, and then maintained stable levels during the last 10 days. During refeeding period, the OC of all treated groups increased rapidly and reconverted to the level of the control within 10 days.