摄食水平对岩原鲤幼鱼摄食代谢和力竭运动后代谢特征的影响

摘要

为考察摄食水平对岩原鲤幼鱼摄食代谢和力竭运动后代谢特征的影响,在(25±0.5)℃条件下,将实验鱼[体质量(13.05±0.17)g]轻度麻醉后灌喂不同摄食水平(通威鲤鱼种饲料,饵料分别为体质量的0％、0.5％、1％和2％)的混合饵料,随后在不同时间点测量其耗氧率并计算相关参数.结果显示,各个摄食处理组和对照组的静止代谢(RMR)无显著性差异；摄食后,各摄食水平组岩原鲤代谢率均呈现先上升后下降的整体变化趋势；0.5％和1％摄食水平的SDA耗能和峰值时间无显著性差异,但都显著低于2％摄食水平组(P＜0.05).摄食水平从0.5％上升到2％,摄食代谢峰值(PMR)和SDA系数无显著性变化；摄食组运动前代谢率显著高于禁食组(P＜0.05),但摄食组的运动代谢峰值、代谢率增量和过量耗氧(EPOC)与禁食组无显著性差异；岩原鲤幼鱼的最大代谢率MMR和MMR/RMR显著大于其PMR和PMR/RMR(P＜ 0.05).研究表明,随着摄食水平的上升,岩原鲤幼鱼主要通过SDA时间的延长来满足SDA耗能增加的需求；摄食对岩原鲤力竭运动后代谢恢复过程无显著性影响.%To investigate the effect of meal size on postprandial metabolic response and excess post-exercise oxygen consumption (EPOC) in juvenile rock carp (Procypris rabaudi)[( 13.05±0.17) g, n=44], experimental fish were lightly anaesthetized and force-fed with compound feed (meal sizes: 0%, 0.5%, 1% and 2% body weight) at (25 ±0.5)℃. After diet offered, oxygen consumption rates at different intervals were measured. Variables of postprandial metabolic and EPOC responses were calculated. The results of present study showed that resting metabolic rates (RMR) were not significantly different among all groups. The postprandial metabolic rate first increased and then slowly decreased to pre-fed level. The time to peak metabolic rate and the energy expended on Specific dynamic action (SDA) in 0.5% and 1% meal size groups were lower than that of 2% meal size group (P＜0.05). The peak metabolic rates (PMR) and the SDA coefficients were not significantly different among 0.5%, 1% and 2% meal size groups. Pre-exercise metabolic rate in feeding group was significantly higher than that of fasting group (P＜0.05). Peak post-exercise metabolic rate, metabolic rate increment and excess post-exercise oxygen consumption magnitude were not significantly different between feeding group and fasting group. The maximum metabolic rate (MMR) and MMR/RMR were significantly higher than PMR and PMR/RMR (P＜0.05). The fish fulfilled the increased energy demand during digestive process by means of prolonged SDA duration with the increase of meal size. EPOC was not influenced by feeding in the fish.