锦鲫幼鱼标准代谢率与生长性能的关联

为考察温水性鲤科鱼类在不同食物资源条件下标准代谢率(Standard metabolic rate, SMR)与其生长性能的关系, 研究在(25.00.5)℃条件下测定体重相近的30尾锦鲫(Carassius auratus)幼鱼的SMR, 将所有实验鱼置于多单元格水槽进行实验处理(摄食与饥饿)。实验时间为4周(0、7d、14d、21d和28d), 包括两周的生长实验(014d)和两周的饥饿实验(1528d)。摄食期间, 于每天上午9: 00和下午21: 00用商业饲料对每尾鱼饱足投喂并记录投喂量。单尾鱼的体重和体长每隔1周测定一次, 而SMR仅在第0、第14和第28天测定。结果显示:(1)锦鲫幼鱼在摄食期间的体重、体长以及SMR均明显上升, 饥饿期间体重和SMR显著降低(P0.05), 但体长变化不明显; SMR不论摄食期间还是饥饿期间呈现较好的稳定性(二者P0.05)。(2)锦鲫幼鱼在摄食期间开始时的SMR (测定Ⅰ)与摄食率(FR)、摄食转化率(FE)以及特定体重生长率(SGRBM)均无相关性, 摄食期间结束时的SMR (测定Ⅱ)仅与FR呈正相关(P0.05), 但与FE以及SGRBM不相关。(3)摄食期间(饥饿期间)实验鱼的第一周日均体重增(减)量与第二周日均体重增(减)量呈正相关, 其体重的增率与减率无显著差异(P0.05)。(4)实验鱼在摄食期间的特定体重增长率(SGRBM)与饥饿期间的不相关(P0.05), 但摄食期间的特定SMR增长率(SGRSMR)与饥饿期间的呈负相关(P0.05)。研究表明在实验室环境中锦鲫幼鱼的SMR具有稳定性, 该种鱼的日均体重变化量保持相近, 此形态变化特征与SMR不相关, 并且该种鱼在实验起始时的SMR的个体差异未能预测其在实验室食物资源变动下生长性能的适应特征。

THE CORRELATIONS BETWEEN STANDARD METABOLIC RATE AND GROWTH PERFORMANCE IN JUVENILE GOLD FISH

The current study investigated the relationship between standard metabolic rate (SMR) and growth perfor-mance using 30 gold fish (Carassius auratus) under the laboratory conditions at (25.0±0.5). All individuals were raised in a man-made laboratory experimental tank for the whole experiment with a 2 weeks feeding and followed by 2 weeks fasting. During feeding stage, each fish was fed twice daily (9:00 and 15:00) and food cunsumption by fish was recor-ded. Two week feeding greatly increased the body mass, body length and SMR, whereas starvation decreased the body mass and SMR without impacting body length (P<0.05). This fish species had similar and stable SMR in feeding period and starvation period (both P<0.05). The SMR1 (at the beginning of feeding experiment) was not correlated with the feeding rate (FR), feeding efficiency (FE) and specific growth rate (SGRBM) of the body mass (P>0.05). SMR2 at the end of feeding experiment was associated with the FR but not FE and SGRBM. Feeding increased body mass and fast-ing decreased the body mass. The theoretic rate of daily increased body mass during the feeding period was not signi-ficantly differ from that of daily decreased body mass during the starvation period (P>0.05) based on the analysis of co-variance. The specific growth rate in SMR (SGRSMR) during the feeding experiment, not SGRBM, was correlated nega-tively with that of the starvation experiment. These results suggest the stable SMR and absolute growth rate of indivi-duals of the juvenile gold fish under the laboratory conditions, but, the SMR of this fish species acclimated at the labora tory surrounding could not predict the adaptive characteristics of growth performance and hence their fitness.