作 者：
曾令清;彭韩柳依;王健伟;庞旭;曹振东;付世建
关键词：
南方鲇;运动代谢;饥饿;个体变异;重复性;游泳运动
摘 要：
为考察温水性鱼类运动代谢的种内个体变异和重复性及其对饥饿的反应,本研究以南方鲇幼鱼为实验对象,在(25±0.5)℃条件下,在饥饿前(测定Ⅰ)后(测定Ⅱ)分别测定饥饿组[(12.15±0.14)g,n=29,饥饿2周]和对照组[(12.00±0.23)g,n=28,每隔一天投喂一次4%~5%体质量黄鳝肉块]的静止代谢率(MO2rest)、临界游泳速度和活跃代谢率(MO2active),并计算有氧代谢空间(AMS=MO2active-M O2rest)、单位距离耗能(COT)和最适游泳速度(Uopt)。结果显示:(1)饥饿之后,饥饿组的MO2rest,MO2active和AMS分别下降了8.6%,36.3%和44.1%,而对照组的M O2rest较其两周前的上升25.9%,其MO2active的无显著变化导致AMS下降了12.6%,但该降幅明显小于饥饿组。(2)饥饿组MO2rest的变异系数(CV)变小,其MO2active和AMS的CV却变大,而对照组相应指标的CV呈反向的变化趋势。饥饿组MO2rest,MO2active和AMS的重复比例均相应低于对照组。(3)饥饿组在两次测定中运动耗氧率与游泳速度的线性方程的斜率保持不变,但其截距明显下降,对照组的斜率和截距均无明显变化;饥饿导致南方鲇运动耗氧率的重复性下降。(4)饥饿组的最小COT(COTm in)和Uopt分别下降25%和11.3%,对照组的COTm in和Uopt也分别降低8%和4.8%,但均明显小于饥饿组。研究表明:在环境食物资源匮乏情况下,南方鲇表现出较高的运动代谢重复性,其降低最适游泳速度并提高游泳效率的策略是对饥饿环境的一种生态适应,可能有助于提高该种鱼的存活率。
译 名：
Repeatability and variation in locomotion metabolism of the juvenile southern catfish during starvation
作 者：
ZENG Lingqing;PENG Hanliuyi;WANG Jianwei;PANG Xu;CAO Zhendong;FU Shijian;College of Life Sciences,Chongqing Normal University;Key Laboratory of Animal Biology of Chongqing Normal University;
关键词：
Silurus meridionalis;;locomotion metabolism;;starvation;;intraspecific variation;;repeatability;;swimming
摘 要：
Consistent individual differences( CIDs) in phenotypes,such as morphology,physiology and behaviour,are a surprisingly widespread phenomenon in most taxa of the animals. CIDs are individual differences in phenotype that are maintained over time( e. g. as measured by repeatability) and across contexts. Many studies showed that a potential linkage between standard metabolic rate( SMR) and other physiological traits( active metabolic rate and aerobic metabolic scope) exists among different taxa of the animals. To examine the effects of starvation on the intraspecific variation and repeatability of locomotion metabolism in a carnivorous fish,the juvenile southern catfish( Silurus meridionalis Chen) which is distributed widely in the Changjiang River and other water areas,was selected as the experimental fish. The resting metabolic rate( MO2rest) and active metabolic rate( MO2active) of both the starvation group[( 12. 15 ± 0. 14) g,n = 29,starved for two weeks]and control group[( 12.00 ±0.23) g,n =28,fed with 4%-5% body weight rice field eel meal every other day]were determined in trialⅠ( before starvation) and trial Ⅱ( after starvation) at( 25 ± 0. 5) ℃. Additionally,the aerobic metabolic scope( AMS = MO2active- MO2rest),cost of transports( COT) and optimal swimming speed( Uopt) were also calculated during the course of the experiment to evaluate the adaptive strategy of locomotive metabolism in this fish species during food fluctuation. The results of our study showed the MO2 rest,MO2activeand AMS of the starvation group decreased significantly by 8. 6%,36. 3 和 44. 1%,respectively,compared to trial Ⅰ,whereas the MO2 restof the control group increased by 25. 9% and its MO2 activedid not change during the course of experiment. This unparalleled change resulted in a 12. 6% decrease in AMS in the control group in trial Ⅱ. The coefficient of variance( CV) of the MO2 restin the starvation group decreased while CV of the MO2 activeand AMS increased in the same group. However,the corresponding index of the control group changed in a negative direction. The repeatability percentages of the MO2 rest,MO2activeand AMS in the starvation group were all lower than those in the control group. The slope of linear regression equation for correlation between locomotor oxygen consumption rate( MO2) and swimming velocity in the starvation group did not change between two trials while the intercept of linear equation reduced profoundly. However,both the slope and intercept did not change in the control group between two trials. Starvation triggered a significant reduction in the repeatability in the locomotor MO2 in the S.meridionalis. The COTminand Uoptreduced significantly by 25% and 11. 3% in the starvation group,respectively.However,the control group showed a smaller decrease in the COTminand Uoptwhich reduced by 8% and 4. 8%,respectively,when compared to the starvation group. Our study suggested that the juvenile S. meridionalis not only exhibited the significant repeatability in MO2 active,AMS and locomotor MO2 with the exception of MO2 rest,but also decreased the optimal swimming speed and hence improved the swimming efficiency when this fish species was facing the low food availability conditions. Integrative regulation in swimming metabolic strategy in the southern catfish may be an adaptive consequence in a fluctuating food resources environment,and may result in an increase of survival for this fish species.
