鲫幼鱼(Carassius auratus)标准代谢个体差异与力竭后代谢特征及行为的关联

为考察鲫(Carassius auratus)幼鱼标准代谢的个体差异与运动力竭后代谢特征和行为的关系,在(25.0±0.5)℃条件下测定80尾鲫幼鱼标准代谢率(SMR),筛选出40尾实验鱼[体重(13.54±0.20)g,体长(8.05±0.07)cm],其中包括20尾高SMR个体和20尾低SMR个体,测定运动至力竭实验鱼的最大代谢率(MMR),并计算代谢空间(AS=MMR-SMR)、相对代谢空间(FAS)和过量耗氧(EPOC)总量,随后测定单尾鱼的快速启动行为[反应时间(RT)、最大线速度(Umax)、最大线加速度(Amax)和120ms移动距离(S120)]以及个性行为(勇敢性和活跃性)。结果显示鲫幼鱼的SMR与AS、FAS和EPOC总量均呈负相关,而与MMR不相关;MMR与AS、FAS和EPOC总量均呈正相关;协方差分析显示高SMR个体组的代谢恢复速率与低SMR个体组无显著差异。鲫幼鱼的SMR与快速启动行为的RT呈正相关,与Amax呈负相关,而与Umax和S120均不相关。在快速启动行为中,鲫幼鱼的RT与Umax、Amax和S120均呈负相关,而Umax与Amax和S120呈正相关。鲫幼鱼的SMR与其勇敢性指标如潜伏期(L)、曝露时间(ET)和探头频率(AF)以及活跃性指标如运动时间比(PTM)、撞墙频率(FHW)均不相关,但鲫幼鱼的PTM与FHW和ET呈正相关。研究表明在实验室条件下鲫幼鱼的能量代谢特征、快速启动和个性行为存在明显的个体差异现象,并且部分表型特征之间存在权衡,提示这些权衡可能是鲫幼鱼的生理、行为与栖息环境相互作用的综合结果。     

鲫幼鱼游泳运动能力的个体变异与表型关联

为考察鲤科鱼类运动能力的个体变异和表型关联及不同加速度对匀加速游泳能力的影响, 研究在(25±0.5)℃条件下测定鲫(Carassius auratus)幼鱼的静止代谢率(Resting metabolic rate, RMR), 通过临界游泳速度(Critical swimming speed, U_crit)法和过量耗氧(EPOC)法获取实验鱼的最大代谢率(Maximum metabolic rate, MMR)、代谢空间(Aerobic scope, AS=MMR-RMR)、相对代谢空间(Factorial aerobic scope, FAS=MMR/RMR)、U_crit及步法转换速度(Gait transition speed, U_gt), 并在不同加速度(0.083、0.167、0.250、0.333 cm/s2)下测定鲫幼鱼的匀加速游泳能力(Constant accelerated test, U_cat)和U_gt。研究发现: 鲫幼鱼的MMR和AS与U_crit均呈正相关, 但RMR与U_crit不相关; 能量代谢参数(MMR、AS、RMR)与U_gt不相关。U_crit法获取的MMR、AS、FAS与EPOC法均无平均值的显著性差异, 但2种方法获得的上述参数具有较高的个体重复性; 鲫幼鱼的能量代谢参数之间存在表型关联并且关联方向不尽相同。鲫幼鱼的U_crit和U_gt均小于各加速度下的U_cat和U_gt, 加速度对U_cat测定无影响但对U_gt有影响。鲫幼鱼的U_gt与U_crit或U_cat呈正相关, 并且其匀加速游泳能力参数在不同加速度下保持较高的重复性。除0.333 cm/s2外, 其他加速度下鲫幼鱼U_cat的无氧代谢组分(U_cat-U_gt)与U_cat呈正相关; 然而, 鲫幼鱼的有氧代谢组分(U_gt)与无氧代谢组分(U_cat-U_gt)呈负相关。研究表明: U_crit法和EPOC法诱导鲫幼鱼的有氧代谢能力无方法学差异; 鲫幼鱼的能量代谢存在表型关联, 其匀加速游泳能力具有稳定个体差异, 并且该种鱼的有氧代谢与无氧代谢存在权衡。     

重复垂钓对鲫幼鱼易钓性和能量代谢及个性的影响

先捕后放是一种重要的鱼类资源保护策略和渔业管理手段。经历先捕后放的被钓鱼类个体的生理与行为会发生变化。当这些个体再次面对人工垂钓诱饵时,可能会呈现更加谨慎的摄饵或鱼钩回避行为。为考察重复垂钓对鱼类易钓性、能量代谢和个性的影响,本研究以鲤科鱼类鲫(Carassius auratus)幼鱼为实验对象,在(25.3±0.1)℃水温条件下对垂钓组和对照组进行3次的能量代谢(标准代谢率,SMR;最大代谢,MMR)和个性(勇敢性、活跃性)测定。其中,垂钓组需进行垂钓实验,而对照组不进行任何垂钓操作。研究发现：(1)重复垂钓显著降低鲫幼鱼的垂钓率,但明显增加单尾平均垂钓时间和整体死亡率。(2)重复垂钓降低鲫幼鱼的体重、肥满度、SMR、MMR、代谢空间(AS)和相对代谢空间(FAS),但整体上不影响勇敢性和活跃性。(3)在测定Ⅰ中,高易钓性个体的体长和开阔区运动时间比大于低易钓性个体,但前者的肥满度小于后者。然而,在测定Ⅱ和Ⅲ中,高易钓性个体的形态参数、能量代谢、个性(勇敢性和活跃性)与低易钓性个体并无差异。研究表明：重复垂钓明显降低鲫幼鱼的易钓性,并且种内个体易钓性的变化方向不尽相同;重复垂钓对鲫幼...     

饥饿对中华倒刺鲃幼鱼代谢、个性和集群的影响

在自然界中,环境变化、季节更替和人为因素造成食物资源时空分布的不均一性,导致鱼类经常面临食物资源短缺的环境胁迫,对其能量代谢和行为造成一定影响。为考察食物资源短缺下暖水性鲤科鱼类能量代谢、个性与集群行为的应对策略及其可能的内在关联,选取中华倒刺鲃(Spinibarbus sinensis)幼鱼为实验对象,分别测定饥饿组(2周)和对照组(维持日粮)在处理前后实验鱼的标准代谢率(Standard metabolic rate,SMR)、个性行为(勇敢性、探索性和活跃性)以及实验处理后的集群行为(凝聚力和协调性)。研究发现:(1)饥饿组和对照组实验过程中实验鱼SMR均显著下降,但仅饥饿组实验鱼SMR具有重复性;(2)饥饿导致中华倒刺鲃幼鱼勇敢性、探索性、活跃性均显著增加;(3)饥饿导致群体成员间距离缩短,游泳速度及其同步性上升。研究表明:饥饿后的中华倒刺鲃不仅适应性降低SMR以减少能量消耗,而且呈现出更高的勇敢性、探索性和活跃性以利于获取食物资源;饥饿迫使中华倒刺鲃群体提高凝聚力和协调性,可能有助于提高群体的生存能力。     

异育银鲫易钓性的表型基础和生态结果及饥饿响应

为考察鲤科鱼类易钓性种内差异的表型基础、生态结果及饥饿响应, 研究以异育银鲫(Carassius auratus gibelio)幼鱼为实验对象, 在饥饿前(对照组)测定其表型特征(能量代谢、游泳能力和个性行为)并垂钓, 随后在饥饿1周后再次垂钓(饥饿组), 最后进行2周的恢复摄食生长实验(恢复组)。垂钓实验具有4个重复, 每个重复的样本量为40尾, 垂钓1.5h即停止, 垂钓20尾为钓出组, 剩余20尾为未钓出组。研究发现: 除钓出组的相对代谢空间(FAS)小于未钓出组外, 钓出组的外部形态(体重、体长和肥满度)、能量代谢参数(标准代谢率SMR、最大代谢率MMR和代谢空间AS)、游泳能力(最大匀加速游泳能力U_cat和最大有氧运动能力U_gt)及个性行为(探索性、活跃性和勇敢性)与未钓出组均无明显差异(所有P>0.05); 在经历捕食者模拟袭击后, 实验鱼勇敢性的潜伏时间比大于探索性, 导致勇敢性的运动时间比和穿门频率小于探索性。SMR与U_cat及U_gt不相关(P>0.05), 但MMR和AS与U_cat及U_gt均呈正相关(P<0.05); 能量代谢参数与个性行为存在部分相关。饥饿增加异育银鲫的垂钓总时间、单尾平均垂钓时间和单尾垂钓时间的变异系数。钓出组在饥饿期的特定生长率(SGR)小于未钓出组, 而恢复期钓出组的SGR与未钓出组无显著差异; 除MMR和AS外, SMR与饥饿期及恢复期的SGR均呈负相关(P<0.05), 即SMR越高个体在饥饿期间的体重下降更快, 在恢复摄食后生长却较慢。研究表明: 异育银鲫幼鱼的易钓性可能不具备表型基础, 并且因环境食物匮乏而降低; 虽然饥饿期间两种易钓性表型个体的生态结果存在差异, 但该生长差异在营养恢复后消失, 表明异育银鲫的易钓性具有一定的环境依赖性。     

鲤幼鱼标准代谢率的个体差异与运动性能和摄食代谢的关系

为考察鲤科鱼类种内个体标准代谢率的差异及其与运动性能和摄食性能的内在关联,本研究以我国广泛分布的鲤(Cyprinids cardio)幼鱼[体重(4.79±0.08)g,n=36]为实验对象,在(25.0±1.0)℃下分别测量实验鱼的标准代谢率(SMR),随后测定单尾鱼的特殊动力作用(SDA)、自发运动、临界游泳速度以及活跃代谢率(MO2active)。实验鱼标准代谢率(SMR)的变幅为76.7~317.6 mg/(kg·h),其变异系数(CV)达24.4%;实验鱼在10 min内的尾鳍摆动次数(P0.05)和摄食代谢峰值(P0.05)均与标准代谢率(SMR)呈正相关;活跃代谢率(MO2active)(P0.05)与摄食代谢峰值以及活跃代谢范围与摄食代谢范围(P0.05)均呈正相关。然而,鲤幼鱼的标准代谢率(SMR)与相对临界游泳速度、活跃代谢率(MO2active)、特殊动力作用(SDA)时间和特殊动力作用(SDA)总量均不相关(所有P0.05)。研究表明,较高标准代谢率(SMR)的鲤幼鱼个体表现较高的活跃性和较强的摄食代谢能力,可能有助于其更易发现食物、逃避天敌以及加快食物处理。     

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。     

中华倒刺鲃能量代谢和热耐受特征的体重效应

为了探讨体重对中华倒刺鲃能量代谢和热耐受特征的影响,在25℃条件下分别测定不同体重大小(1、10、25、50 g组)中华倒刺鲃的静止代谢率(Resting metabolic rate,RMR)、力竭运动后过量耗氧(Excess post-exercise oxygen consumption,EPOC)和热耐受参数。随体重的增加,中华倒刺鲃个体RMR、最大代谢率(Maximum metabolic rate,MMR)、代谢空间(Metabolic scope,MS)和EPOC均显著增加(P0.05);单位体重RMR、MMR和MS则均显著降低,而单位体重EPOC随体重的增加显著增加(P0.05)。RMR、MMR、MS和EPOC的代谢尺度指数分别为0.796、0.834、0.849和1.137且显著大于2/3,因此中华倒刺鲃的能量代谢参数均呈异速度增加的关系而变化。这些变化可能与其个体变大游泳运动能力增强导致能量代谢需求增加相关。中华倒刺鲃临界低温(Critical thermal minimum,CT_(min))和致死低温(Lethal thermal minimum,IL_(min))与体重之间均呈"微笑型"二次函数的关系,临界高温(Critical thermal maximum,CT_(max))和致死高温(Lethal thermal maximum,IL_(max))均呈"钟型"二次函数的关系,因此中等大小的中华倒刺鲃具有更强的热耐受能力。这种非线性关系可能与其生长发育阶段和温度驯化历时有关。     

中华倒刺鲃幼鱼能量代谢特征个体差异及生态关联

为了探讨鱼类能量代谢特征个体变异及其生态关联, 以中华倒刺鲃(Spinibarbus sinensis)幼鱼为实验对象, 在25℃条件下测定44尾实验鱼的静止代谢率(Resting metabolic rate, RMR)、力竭运动后峰值代谢率(Peak metabolic rate, PMR)、力竭运动后过量耗氧(Excess post-exercise oxygen consumption, EPOC)、低氧胁迫后峰值代谢率PMR和低氧胁迫后过量耗氧(Excess post-hypoxia oxygen consumption, EPHOC)。研究发现, 中华倒刺鲃能量代谢特征参数存在较大个体差异, RMR、力竭运动后PMR、EPOC、低氧胁迫后PMR和EPHOC分别为193.62—460.33 [mg O₂/(kg·h)]、617.9—2165.02 [mg O₂/(kg·h)]、28.76—267.20 mg O₂/kg、484.3—1142.97 [mg O₂/(kg·h)]和30.27—211.88 mg O₂/kg。力竭运动后PMR(r=0.348, P=0.010)和低氧胁迫后PMR(r=0.449, P=0.002)与RMR间均呈显著正相关; EPOC与RMR间呈显著负相关(r=–0.426, P=0.004), 而EPHOC与RMR间的关系不显著(r=–0.292, P=0.054); 力竭运动后PMR与EPOC间(r=0.424, P=0.004)和低氧胁迫后PMR与EPHOC间(r=0.391, P=0.009)均呈显著正相关。力竭运动后PMR与低氧胁迫后PMR(r=0.673, P<0.001)和EPOC与EPHOC(r=0.526, P<0.001)在个体差异均显著正相关; 然而力竭运动后PMR和EPOC分别显著高于低氧胁迫后PMR与EPHOC(P<0.05)。研究表明: 维持代谢较高的中华倒刺鲃个体有助于其快速提升有氧功率输出以维持高的游泳运动能力; 而较低维持代谢个体具有相对较高的EPHOC有助于机体在极端环境条件下提升其低氧耐受能力。中华倒刺鲃能量特征的个体变异可能是经长期自然选择适应环境的结果。     

PFOS对中华倒刺鲃幼鱼爆发游泳及运动后代谢恢复的影响

为探究水体全氟辛烷磺酸(PFOS)污染对鱼类爆发游泳及其代谢恢复能力的影响, 将中华倒刺鲃幼鱼(Spinibarbus sinensis)暴露在不同浓度(0、0.32、0.8、2和5 mg/L)PFOS后, 测定PFOS暴露对其静止代谢率(RMR)、爆发游泳速度(U_burst)以及运动力竭后代谢恢复特征的影响。结果发现, 暴露浓度对实验鱼的U_burst和相对爆发游泳速度(rU_burst)均影响显著(P<0.05), 5 mg/L PFOS暴露导致U_burst和rU_burst分别下降了17.4%和10.8%, PFOS对rU_burst的影响表现出“非单调剂量效应”; 暴露浓度对实验鱼的RMR影响显著(P<0.05), 5 mg/L PFOS暴露导致RMR显著升高, 但PFOS对运动后代谢峰值(MMR)、代谢率增量(MS)、代谢变化倍率(F-MS)、力竭运动后过量氧耗(EPOC)无显著影响(P>0.05)。研究结果提示: PFOS污染改变实验鱼能量代谢水平的下限, 而对其代谢水平的上限无明显的限制性作用; PFOS污染将可能对鱼类捕食——逃避捕食者、穿越激流寻找适宜生境等生存关联的生命活动起到负面影响, 但对无氧代谢关联的代谢恢复能力无显著的生态毒理效应。     

Altitudinal and seasonal effects on aerobic metabolism of deer mice

Summary I compared the maximal aerobic metabolic rates ( ), field metabolic rates (FMR), aerobic reserves ( -FMR), and basal metabolic rates (BMR) of wild and recently captured deer mice from low (440 m) and high (3800 m) altitudes. To separate the effects of the thermal environment from other altitudinal effects, I examined mice from different altitudes, but similar thermal environments (i.e., summer mice from high altitude and winter mice from low altitude). When the thermal environment was similar, , FMR, and aerobic reserve of low and high altitude mice did not differ, but BMR was significantly higher at high altitude. Thus, in the absence of thermal differences, altitude had only minor effects on the aerobic metabolism of wild or recently captured deer mice.At low altitude, there was significant seasonal variation in , FMR, and aerobic reserve, but not BMR. BMR was correlated with , but not with FMR. The significant positive correlation of BMR with indicates a cost of high , because higher BMR increases food requirements and energy use during periods of thermoneutral conditions.Abbreviations BMR basal metabolic rate - FMR field metabolic rate - partial pressure of oxygen - T _a ambient temperature - T _b body temperature - T _e operative temperature - maximal aerobic metabolic rate     

Studies on the oxygen consumption of a tropical intertidal limpet Cellana radiata (Born): Effect of body size and tidal rhythm

Some observations on the effect of body size on the respiratory metabolism of the tropical limpet Cellana radiata (Born) were made. In addition the tidal rhythm in the oxygen consumption of the animals was also studied.     

Changes in body temperature influence the scaling of VO2max and aerobic scope in mammals

Debate on the mechanism(s) responsible for the scaling of metabolic rate with body size in mammals has focused on why the maximum metabolic rate (VO2max ) appears to scale more steeply with body size than the basal metabolic rate (BMR). Consequently, metabolic scope, defined as VO2max/BMR, systematically increases with body size. These observations have led some to suggest that VO2max, and BMR are controlled by fundamentally different processes, and to discount the generality of models that predict a single power-law scaling exponent for the size dependence of the metabolic rate. We present a model that predicts a steeper size dependence for VO2max than BMR based on the observation that changes in muscle temperature from rest to maximal activity are greater in larger mammals. Empirical data support the model's prediction. This model thus provides a potential theoretical and mechanistic link between BMR and VO2 max.     

Utilization of metabolic scope in relation to feeding and activity by individual and grouped zebrafish, Brachydanio rerio (Hamilton-Buchanan)

Metabolic scope and its utilization in relation to feeding and activity were measured in individual and grouped zebrafish (weight range, 430–551 mg) at 24° C by respirometry. Mean maximum metabolic rate, induced by swimming to exhaustion, R_max(i), was 1223 (s.d. , 157) mg O₂, kg^?1 h^?1 for individuals. Standard metabolic rate, R_s. was 364 mg O₂ kg^?1 h^?1, as estimated by extrapolating to zero activity from measurements of unfed, spontaneously active individuals. Mean routine metabolic rate, R_rout, of individuals was 421 (s.d. , 58) mg O₂, kg_-1 h_-1. The mean voluntary maximum metabolic rate, R_max(v), following transfer of minimally exercised fish to the respirometer, was 1110 (s.d. , 83) mg O₂ kg ^?1 h^?1 for groups of six fish, and was not significantly different from the value measured for individuals, 1066 (s.d. , 122) mg O₂, kg^?1 h^?1. Grouped fish acclimated to the respirometer more slowly than individual fish and exhibited significantly higher R_rout, apparently a result of greater social interaction and activity in groups. Mean R_rout for groups was 560 (s.d. , 78) mg O₂, kg^?1 h^?1. While groups of zebrafish fed a ration of 5% wet body weight day^?1 exhibited consistently higher metabolic rates than fish fed rations of 2.5% wet body weight day^?1 the high ration group still used only a maximum of 77% of the metabolic scope. Zebrafish of the size studied do not appear to demonstrate a high degree of conflict in utilization of metabolic scope by different respiratory components. The metabolic rates measured for zebrafish are among the highest yet measured for fish of similar size and at similar temperatures.     

Thermoregulation in three species of Afrotropical subterranean mole-rats (Rodentia: Bathyergidae) from Zambia and Angola and scaling within the genus Cryptomys

The thermoregulatory characteristics of three species of Cryptomys from Zambia and Angola are examined and, together with published data on four other species of Cryptomys from southern Africa, used to determine whether scaling occurs in this genus of subterranean rodents. The thermoregulatory properties of acclimated giant Zambian mole-rats, Cryptomys mechowi ( =267 g), Angolan mole-rats, Cryptomys bocagei ( =94 g) and Zambian common mole-rats Cryptomys hottentotus amatus ( =77 g) are as follows. Mean resting metabolic rates (RMRs) within the respective thermoneutral zones were 0.60±0.08 cm³ O₂ g^-1 h^-1 (n=12) for C. mechowi; 0.74±0.06 cm³ O₂ g^-1 h^-1 (n=8) for C. bocagei and 0.63±0.06 cm³O₂ g^-1 h^-1 (n=21) for C. h. amatus. The thermoneutral zones (TNZs) of all three species are narrow: 29–30°C for C. mechowi; 31.5–32.5°C for C. bocagei and 28–32° C for C. h. amatus. The increase in mean RMR at the lowest temperatures tested (15° C for C. mechowi, 18° C for C. bocagei and C. h. amatus) was 2.35, 2.2 and 3.82 times their RMR in the TNZ respectively. Body temperatures are low, 34±0.53° C (n=24) for C. mechowi, 33.7±0.32° C (n=20) for C. bocagei and 33.8±0.43° C (n=40) for C. h amatus. At the lower limit of thermoneutrality, conductances are 0.09±0.01 cm³ O₂ g^-1 h^-1 °C^-1 (n=30) in C. mechowi; 0.12±0.01 cm³ O₂ g^-1 h^-1 °C^-1 (n=20) in C. bocagei and 0.12±0.03 cm³ O₂ g^-1 h^-1 °C^-1 (n=32) in C. h. amatus. The range in mean body mass among the seven species of Cryptomys examined for scaling was 60 g (C. darlingi) to 267 g (C. mechowi). There is no clear relationship between RMR within the TNZ and body mass. The resultant relationship is represented by the power curve RMR=2.45 mass^-0.259.     

The covariance between metabolic rate and behaviour varies across behaviours and thermal types: meta‐analytic insights

Energy metabolism has received much attention as a potential driver of repeatable among‐individual differences in behaviour (animal personality). Several factors have been hypothesized to mediate this relationship. We performed a systematic review with a meta‐analysis of >70 studies comprised of >8000 individuals reporting relationships between measures of maintenance metabolic rates (i.e. basal metabolic rate, resting metabolic rate, and standard metabolic rate) and behaviour. We evaluated support for three hypothesized mediators: (i) type of behaviour, (ii) opportunities for energy re‐allocation, and (iii) magnitude of energetic constraints. Relationships between measures of maintenance metabolic rate (MR) and behaviour are predicted to be strongest for behaviours with strong consequences for energy turnover (acquisition or expenditure). Consistent with this, we found that behaviours with known consequences for energy gain (e.g. foraging, dominance, boldness) or expenditure (e.g. maximum sprint speed, sustained running speed, maximum distance travelled, etc.) had strong positive correlations with MR, while behaviours with putatively weak and/or inconsistent associations with net energy gain or loss (e.g. exploration, activity, sociability) were not correlated with MR. Greater opportunities for energy reallocation are predicted to weaken relationships between MR and behaviour by creating alternative pathways to balance energy budgets. We tested this by contrasting relationships between MR and behaviour in ectotherms versus endotherms, as thermoregulation in endotherms creates additional opportunities for energy reallocation compared with ectotherms. As predicted, the relationship between behaviour and MR was stronger in ectotherms compared with endotherms. However, statistical analyses of heterogeneity among effect sizes from different species did not support energy re‐allocation as the main driver of these differences. Finally, we tested whether conditions where animals face greater constraints in meeting their energy budgets (e.g. field versus laboratory, breeding versus non‐breeding) increased the strength of the relationship between MR and behaviour. We found that the relationship between MR and behaviour was unaffected by either of these modifiers. This meta‐analysis provides two key insights. First, we observed positive relationships of similar magnitude between MR and behaviours that bring in net energy, and behaviours that cost net energy. This result is only consistent with a performance energy‐management model. Given that the studies included in our meta‐analysis represent a wide range of taxa, this suggests that the performance model may be the most common model in general. Second, we found that behaviours with putatively weak or inconsistent consequences for net energy gain or expenditure (exploration, activity, sociability) show no relationship with MR. The lack of relationship between MR and behavioural traits with weak and/or inconsistent consequences for energy turnover provides the first systematic demonstration of the central importance of the ecological function of traits in mediating relationships between MR and behaviour.     

Do the high energy lifestyles of shorebirds result in high maximal metabolic rates? Basal and maximal metabolic rates in least and pectoral sandpipers during migration

Shorebirds have high resting and field metabolic rates relative to many other bird groups, and this is posited to be related to their high‐energy lifestyle. Maximum metabolic outputs for cold or exercise are also often high for bird groups with energetically demanding lifestyles. Moreover, shorebirds demonstrate flexible basal and maximal metabolic rates, which vary with changing energy demands throughout the annual cycle. Consequently, shorebirds might be expected to have high maximum metabolic rates, especially during migration periods. We captured least Calidris minutilla and pectoral C. melanotos sandpipers during spring and fall migration in southeastern South Dakota and measured maximal exercise metabolic rate (MMR; least sandpipers only), summit metabolic rate (M_sum, maximal cold‐induced metabolic rate) and basal metabolic rate (BMR, minimum maintenance metabolic rate) with open‐circuit respirometry. BMR for both least and pectoral sandpipers exceeded allometric predictions by 3–14%, similar to other shorebirds, but M_sum and MMR for both species were either similar to or lower than allometric predictions, suggesting that the elevated BMR in shorebirds does not extend to maximal metabolic capacities. Old World shorebirds show the highest BMR during the annual cycle on the Arctic breeding grounds. Similarly, least sandpiper BMR during migration was lower than on the Arctic breeding grounds, but this was not the case for pectoral sandpipers, so our data only partially support the idea of similar seasonal patterns of BMR variation in New World and Old World shorebirds. We found no correlations of BMR with either M_sum or MMR for either raw or mass‐independent data, suggesting that basal and maximum aerobic metabolic rates are modulated independently in these species.     

恒温脊椎动物最大持续能量代谢率及其研究进展

研究最大持续代谢率具有重要的理论和实践意义,本文概述了近年来国外对脊椎动物最大持续代谢率研究的成果,概括介绍了限制最大持续代谢率的四个假说：（1）食物限制假说（food limit hypothesis) ,(2)外周限制假说（peripheral limit hypotheisis),(3)中心限制假说（central limit hypothesis)和（4）对称性形态构成假说（symmorphosis hypothesis),分析了静止代谢率随持续代谢率的增加而增加的机理,讨论了最大持续代谢率对动物的生态进化意义,最后指出了最大持续代谢率研究中可能的发展前景。     

Plasma osmolality and oxygen consumption of perch Perca fluviatilis in response to different salinities and temperatures

The present study determined the blood plasma osmolality and oxygen consumption of the perch Perca fluviatilis at different salinities (0, 10 and 15) and temperatures (5, 10 and 20° C). Blood plasma osmolality increased with salinity at all temperatures. Standard metabolic rate (SMR) increased with salinity at 10 and 20° C. Maximum metabolic rate (MMR) and aerobic scope was lowest at salinity of 15 at 5° C, yet at 20° C, they were lowest at a salinity of 0. A cost of osmoregulation (SMR at a salinity of 0 and 15 compared with SMR at a salinity of 10) could only be detected at a salinity of 15 at 20° C, where it was 28%. The results show that P. fluviatilis have capacity to osmoregulate in hyper‐osmotic environments. This contradicts previous studies and indicates intraspecific variability in osmoregulatory capabilities among P. fluviatilis populations or habitat origins. An apparent cost of osmoregulation (28%) at a salinity of 15 at 20° C indicates that the cost of osmoregulation in P. fluviatilis increases with temperature under hyperosmotic conditions and a power analysis showed that the cost of osmoregulation could be lower than 12·5% under other environmental conditions. The effect of salinity on MMR is possibly due to a reduction in gill permeability, initiated to reduce osmotic stress. An interaction between salinity and temperature on aerobic scope shows that high salinity habitats are energetically beneficial during warm periods (summer), whereas low salinity habitats are energetically beneficial during cold periods (winter). It is suggested, therefore, that the seasonal migrations of P. fluviatilis between brackish and fresh water is to select an environment that is optimal for metabolism and aerobic scope.     

The metabolic rate of roach in relation to body size and temperature

Standard and routine metabolic rates of roach Rutilus rutilus for a wide size and temperature range (3–200 g, 5–23° C) were analysed by automated, computerized intermittent flow respirometry. The mass exponent b ranged from 0·68 to 0·82 for standard metabolism, and from 0·65 to 0·92 for routine metabolism depending on the experimental temperature. For routine metabolism b was lowest at 10° C. At both decreasing and increasing temperatures, b increased significantly. Roach were exponentially temperature-dependent for both metabolic levels. For roach <20 g, however, an asymptotic relationship was observed between temperature and routine metabolic rate. The 'flattening of the curve' in the latter case may be explained by reduced spontaneous activities at the lower threshold of the preferred temperature range.