College of Resources and Environmental Science, Key Laboratory of Southwest Resource Exploitation and Environmental Disaster Controlling Project of the Education Ministry, Chongqing University, Chongqing 400030, China; Laboratory of Evolutionary Physiology and Behaviour, Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing, 400047, China.
College of Resources and Environmental Science, Key Laboratory of Southwest Resource Exploitation and Environmental Disaster Controlling Project of the Education Ministry, Chongqing University, Chongqing 400030, China.
J Therm Biol. 2014 May;42:25-32. doi: 10.1016/j.jtherbio.2014.02.014. Epub 2014 Feb 17.
We measured the following variables to investigate the effects of fasting and temperature on swimming performance in juvenile qingbo (Spinibarbus sinensis): the critical swimming speed (Ucrit), resting metabolic rate (ṀO2rest) and active metabolic rate (ṀO2active) of fish fasting for 0 (control), 1, 2 and 4 weeks at low and high acclimation temperatures (15 and 25°C). Both fasting treatment and temperature acclimation had significant effects on all parameters measured (P<0.05). Fasting at the higher temperature had a negative effect on all measured parameters after 1 week (P<0.05). However, when acclimated to the lower temperature, fasting had a negative effect on Ucrit until week 2 and on (ṀO2rest), (ṀO2active) and metabolic scope (MS, (ṀO2active)-(ṀO2rest)) until week 4 (P<0.05). The values of all parameters at the lower temperature were significantly lower than those at the higher temperature in the identical fasting period groups except for (ṀO2rest) of the fish that fasted for 2 weeks. The relationship between fasting time (T) and Ucrit was described as Ucrit(15)=-0.302T(2)-0.800T+35.877 (r=0.781, n=32, P<0.001) and Ucrit(25)=0.471T(2)-3.781T+50.097 (r=0.766, n=32, P<0.001) at 15 and 25°C, respectively. The swimming performance showed less decrease in the early stage of fasting but more decrease in the later stage at the low temperature compared to the high temperature, which might be related to thermal acclimation time, resting metabolism, respiratory capacity, energy stores, enzyme activity in muscle tissue and energy substrate utilization changes with fasting between low and high temperatures. The divergent response of the swimming performance to fasting in qingbo at different temperatures might be an adaptive strategy to seasonal temperature and food resource variation in their habitat.
我们测量了以下变量，以研究禁食和温度对青波（Spinibarbus sinensis）幼鱼游泳性能的影响：在低和高适应温度（15 和 25°C）下禁食 0（对照）、1、2 和 4 周的临界游泳速度（Ucrit）、静止代谢率（ṀO2rest）和主动代谢率（ṀO2active）。禁食处理和温度驯化对所有测量参数都有显著影响（P<0.05）。在较高温度下禁食对所有测量参数在第 1 周后都有负面影响（P<0.05）。然而，当适应较低温度时，禁食对 Ucrit 的影响持续到第 2 周，对（ṀO2rest）、（ṀO2active）和代谢范围（MS，（ṀO2active）-（ṀO2rest））的影响持续到第 4 周（P<0.05）。除了禁食 2 周的鱼的（ṀO2rest）外，所有参数在较低温度下的值在相同的禁食期组中都显著低于较高温度下的值。禁食时间（T）与 Ucrit 的关系描述为 Ucrit(15)=-0.302T(2)-0.800T+35.877（r=0.781，n=32，P<0.001）和 Ucrit(25)=0.471T(2)-3.781T+50.097（r=0.766，n=32，P<0.001），分别在 15 和 25°C。与高温相比，低温下游泳性能在禁食早期下降较少，但在后期下降较多，这可能与热驯化时间、静止代谢、呼吸能力、能量储备、肌肉组织中酶活性以及低温和高温下禁食时能量底物利用的变化有关。青波在不同温度下对禁食的游泳性能的不同反应可能是对其栖息地季节性温度和食物资源变化的一种适应策略。
