Postprandial metabolism of Pacific bluefin tuna (Thunnus orientalis)
Postprandial metabolism of Pacific bluefin tuna (Thunnus orientalis)
复制标题
DOI：
10.1242/jeb.043455
复制
发表时间：
2010-07-15
影响因子：
2.8
通讯作者：
Block, B. A.
中科院分区：
文献类型：
--
作者：
Clark, T. D.;Brandt, W. T.;Block, B. A.
特定动力作用(SDA)被定义为食物在摄入、消化、吸收和同化过程中所消耗的能量。这项研究首次提供了任何物种个体金枪鱼SDA反应的数据。太平洋蓝鳍金枪鱼幼鱼(东方金枪鱼；体重9.7-11.0。分别喂食已知数量的食物，主要是鱿鱼和沙丁鱼(能量范围为1680-8749)。KJ，与金枪鱼体重的4%-13%相似)。在泳道呼吸仪上，以1.Bl的游泳速度测量餐后的耗氧率(M-O2)。S-1，水温20℃。摄食后，所有鱼的M-O2显著高于常规水平[常规代谢率。174+/-9毫克Kg(-1)h(-1)]。SDA过程中的M-O2峰值范围为250~440。Mg.Kg(-1)h(-1)(1.5~2.3倍RMR)，与膳食能量含量呈线性相关。餐后血氧饱和度增加的持续时间为21。H到33。H取决于膳食能量含量。因此，SDA过程中使用的总能量随着膳食能量的线性增加而增加，范围从170kJ到688kJ，因此在所有实验中，SDA过程占摄入能量的9.2+/-0.7%。这些值表明，与大多数其他鱼类相比，东方梭鱼的食物转换速度快，效率高。植入的档案温度标签记录了与SDA相关的内脏温度(T-V)的增加。M-O2在消化期2-3结束时恢复到常规水平。H早于T-V。消化过程中M-O2和T-V的定性模式相似，加强了对T-V的档案测量可以为自由游泳的蓝鳍金枪鱼在自然环境中的能量学和栖息地利用提供新的见解的可能性。尽管食物转化效率很高，但SDA很可能是野生蓝鳍金枪鱼每日能量收支的重要组成部分，因为它们经常高摄取饲料。
Specific dynamic action (SDA) is defined as the energy expended during ingestion, digestion, absorption and assimilation of a meal. This study presents the first data on the SDA response of individual tunas of any species. Juvenile Pacific bluefin tunas (Thunnus orientalis; body mass 9.7-11.0. kg; N=7) were individually fed known quantities of food consisting primarily of squid and sardine (meal energy range 1680-8749. kJ, similar to 4-13% of tuna body mass). Oxygen consumption rates (M-O2) were measured in a swim tunnel respirometer during the postprandial period at a swimming speed of 1. body length (BL). s-1 and a water temperature of 20 degrees C. M-O2 was markedly elevated above routine levels in all fish following meal consumption [ routine metabolic rate (RMR). 174 +/- 9. mg. kg(-1)h(-1)]. The peak M-O2 during the SDA process ranged from 250 to 440. mg. kg(-1)h(-1) (1.5-2.3 times RMR) and was linearly related to meal energy content. The duration of the postprandial increment in M-O2 ranged from 21. h to 33. h depending upon meal energy content. Consequently, the total energy used in SDA increased linearly with meal energy and ranged from 170kJ to 688kJ, such that the SDA process accounted for 9.2 +/- 0.7% of ingested energy across all experiments. These values suggest rapid and efficient food conversion in T. orientalis in comparison with most other fishes. Implanted archival temperature tags recorded the increment in visceral temperature (T-V) in association with SDA. M-O2 returned to routine levels at the end of the digestive period 2-3. h earlier than T-V. The qualitative patterns in M-O2 and T-V during digestion were similar, strengthening the possibility that archival measurements of T-V can provide new insight into the energetics and habitat utilization of free-swimming bluefin in the natural environment. Despite efficient food conversion, SDA is likely to represent a significant component of the daily energy budget of wild bluefin tunas due to a regular and high ingestion of forage.