中国石龙子热生物学的研究

通过研究中国石龙子选择体温，临界温度与实验温度对该种的体温，疾跑速，摄食量，食物通过时间，表现消化系数，同化效率和生长的影响发现，中国石龙子选择体温３１．２℃，临界高，低温分别为４２．３和６．３℃，恒温室内中国石龙子的体温与实验温度接近，温度对中国石龙子的疾跑速有显著影响，３４℃中动物疾跑速最高，过高或过低实验温度中的动物疾跑减慢，温度对中国石龙子食物通过时间，单位体重摄食量，粪尿能值，表观消化系     

雄性山地麻蜥选择体温、热耐受性及温度对食物同化和运动表现的影响

研究了捕自安徽宿州的成年雄性山地麻蜥 (Eremiasbrenchleyi)选择体温、热耐受性、温度对食物同化和运动表现的影响。结果显示 :①选择体温、临界高温和临界低温的平均值分别为 33 7、 43 6和 3 3℃。②环境温度在 2 6～ 38℃时 ,对山地麻蜥食物通过时间、摄食量、表观消化系数 (ADC)、同化效率 (AE)和运动表现有显著的影响 ;在 2 6～ 30℃时食物通过时间随温度升高而缩短 ,超过 30℃则随温度升高而延长 ;在 2 6和 2 8℃时 ,摄食量、ADC和AE均小于更高温度的对应值。③体温在 19～ 34℃ ,蜥蜴的疾跑速随体温上升而加快 ,31和 34℃时最快 ,超过 34℃后随体温升高而减慢 ;31和 34℃时的持续运动距离最长 ,超过 36℃后随体温升高而显著缩短 ,但体温 19～ 36℃蜥蜴的持续运动距离无显著差异 ;19～ 34℃蜥蜴的跑道停顿次数较少 ,无显著差异 ,超过 34℃后显著增加。     

雄性山地麻晰选择体温、热耐受性及温度对食物同化和运动表现的影响

研究了捕自安徽宿州的成年雄性山地麻蜥（Eremias brenchleyi）选择体温、热耐受性、温度对食物同化和运动表现的影响。结果显示：①选择体温、临界高温和临界低温的平均值分别为33.7、43.6和3.3℃。②环境温度在26－38℃时,对山地麻蜥食物通过时间、摄食量、表观消化系数（ADC）、同化效率（AE）和运动表现有显著的影响;在26－30℃时食物通过时间随温度升高而缩短,通过30℃则随温度升高而延长;在26和28℃时,摄食量、ADC和AE均小于更高温度的对应值。③体温在19－34℃,蜥蜴的疾跑速随体温上升而加快,31和34℃时最快,超过34℃后随体温升高而减慢;31和34℃时的持续运动距离最长,超过36℃后随体温升高而显著缩短,但体温19－36℃蜥蜴的持续运动距离无显著差异;19－34℃蜥蜴的路道停顿次数较少,无显著差异,超过34℃后显著增加。     

青海沙蜥的热耐受性、选择体温及摄食和运动表现的热依赖性

研究了青海沙蜥(Phrynocephalus vlangalii)成体的选择体温、热耐受性及食物同化和运动表现的热依赖性。结果显示:选择体温、临界低温和临界高温无显著的两性差异,其平均值分别为33.3、0.9℃和46.9℃。在27-35℃实验温度范围内,体温显著影响日摄食量,表观消化系数(ADC)和同化效率(AE)无显著影响。停顿次数随着体温的升高而降低,至39℃时停顿次数最少,但与37℃和41℃处理下的停顿次数无显著差异。疾跑速在17-39℃范围内随体温升高而加快,在39℃体温下最快。体温大于39℃后速度减慢。在17-27℃体温范围内,随体温的升高持续运动距离无显著差异。持续运动距离在29-41℃体温下大于较低体温(17-27℃)下的测定值。     

热耐受性及温度对食物同化的影响

研究变色树蜥(Calotes versicolor)的选择体温、热耐受性、温度对食物同化的影响.结果显示:①幼体的选择体温、临界高温和临界低温的平均值分别为32.6、41.7℃和 7.7℃;成体的选择体温、临界高温和临界低温的平均值分别为33.1、42.0℃和8.2℃.②环境温度在26～34℃时,对变色树蜥食物通过时间和摄入能有显著的影响;对表观消化系数(ADC)和同化效率(AE)无显著的影响;在28～34℃时食物通过时间随温度升高而缩短;在26、28℃和30℃时,摄入能小于更高温度的对应值.     

原尾蜥虎的选择体温、热耐受性和食物同化的热依赖性

(Tsel)、热耐受性和体温对食物同化的影响。Tsel无显著的日时间变化,两性个体的Tsel、临界低温(CTMin)和临界高温(CTMax)无显著的差异。Tsel、CTMin和CTMax的平均值分别为30.9℃、3.2℃和43.3℃。体温对动物食物通过时间有显著的影响。在25℃-33℃范围内,食物通过时间随体温升高而缩短;体温超过33℃后,食物通过时间随体温升高而延长。温度对原尾蜥虎的摄食量、表观消化系数(ADC)和同化效率(AE)有显著的影响。在25℃-37℃范围内,动物在低体温下(25℃和27℃)的摄食量、ADC和AE小于更高体温下动物的对应数值。种间比较结果显示,原尾蜥虎是生活于南方的蜥蜴中具有较强耐受极端体温的种类。     

环境温度对(虫)蜓能量需求和食物同化影响的研究

研究了环境温度对成体Yan蜓能量需求和食物同化的影响。在24℃—33℃范围内,雌、雄Yan蜓摄入能、表观消化系数和同化效率的两性差异不显著。温度显著影响Yan蜓的能量摄入和同化效率,27℃时的能量摄入显著高于30℃和33℃,27℃时的同化效率显著高于24℃和33℃。各实验温级表观消化系数的差异不显著。结果表明：环境温度对Yan蜓能量需求和食物同化的影响显著。     

中华花龟幼体热耐受性、体温昼夜变化和运动表现的热依赖性

为研究中华花龟(Ocadia sinensis)幼体的热耐受性和运动表现热依赖性，设计了具有和缺乏温度梯度两种热环境，研究幼龟体温的昼夜变化。高、低温耐受性分别用临界高温和临界低温表示，体温为泄殖腔温度，水温和气温分别是幼龟所处位置的水温和1cm高气温。临界高温和临界低温分别为41．9℃和1．8℃。在有温度梯度的热环境中，体温、水温和气温平均值有显著的昼夜差异，水温和体温的日平均值无显著差异，两者均大于气温的日平均值。在缺乏温度梯度的热环境中，体温、气温和水温平均值亦有显著的昼夜差异，但气温、水温和体温的日平均温度无显著差异。温度梯度是幼龟进行体温调节不可或缺的条件，选择体温有显著的昼夜变化，最大值和最小值分别为29．2℃和25．4℃。在02：00—06：00时间段内，幼龟选择体温明显较低，其它测定时刻的选择体温无显著差异。幼龟各测定时刻的平均体温与平均气温和水温均呈正相关。处于温度梯度中幼龟特定气温的体温比处于缺乏温度梯度中的幼龟高3．7℃，这种差异是前者利用温度梯度进行体温调节的结果；处于不同热环境中幼龟特定水温的体温无显著差异。体温显著影响幼龟的运动表现。18—39℃体温范围内，疾跑速随体温增加而增加，36℃和39℃体温的幼龟疾跑速最大；体温达到41℃时，疾跑速显著下降。体温较高的幼龟的最大持续运动距离大于体温较低的幼龟。偏相关分析显示，疾跑速与最大持续运动距离和停顿次数呈显著的正相关，停顿次数与最大持续运动距离呈负相关。     

体温、摄食、断尾和雌体繁殖状态对原尾蜥虎运动表现的影响

设计4项实验研究4种内外因素(环境温度、摄食、断尾和怀卵状态)导致的肇庆原尾蜥虎运动表现种群内变异.环境温度通过影响体温而影响原尾蜥虎运动表现.两性成体疾跑速均具有在低体温范围内随体温升高而加快、在高体温范围内随体温升高而降低的一般模式.在任何体温下成年雌体的疾跑速均略大于雄体,但两者平均值在统计上无显著差异.体温对原尾蜥虎最大持续运动距离的影响存在两性间差异.成年雌体的最大持续运动距离在低体温范围(从17 ℃到27 ℃)内随体温升高而增加,而在相对较高的体温范围(从27 ℃到37 ℃)内无显著变化,成年雄体在实验体温范围(从17 ℃到37 ℃)内无显著变化;在任何体温下成年雌体的最大持续运动距离均显著大于雄性.性别与体温相互作用对最大持续运动距离有显著影响.两性个体的平均疾跑速和最大持续运动距离呈显著的正相关.当去除最大持续运动距离差异的影响后发现,疾跑速两性差异统计上仍不显著.摄食、尾自切和雌体怀卵在两个实验温度下(27 ℃和31 ℃)均减小壁虎疾跑速;而仅尾自切减小壁虎的最大持续运动距离,摄食和雌体怀卵对其无影响.以上3种因子分别与体温、性别的交互作用均不显著.这些结果说明生理限制和尾自切是原尾蜥虎运动能力变异的重要来源.一些内外因素能近因性诱导蜥蜴功能表现发生一定程度的种群内变异.     

Northern grass lizards (<Emphasis Type="Italic">Takydromus septentrionalis</Emphasis>) from different populations do not differ in thermal preference and thermal tolerance when acclimated under identical thermal conditions

We acclimated adults of Takydromus septentrionalis (northern grass lizard) from four localities (populations) under identical thermal conditions to examine whether local thermal conditions have a fixed influence on thermal preference and thermal tolerance in the species. Selected body temperature (Tsel), critical thermal minimum (CTMin), and critical thermal maximum (CTMax) did not differ between sexes and among localities in lizards kept under identical laboratory conditions for ∼5 months, and the interaction effects between sex and locality on these measures were not significant. Lizards acclimated to the three constant temperatures (20, 25, and 35°C) differed in Tsel, CTMin, and CTMax. Tsel, CTMin, and CTMax all shifted upward as acclimation temperature increased, with Tsel shifting from 32.0 to 34.1°C, CTMin from 4.9 to 8.0°C, and CTMax from 42.0 to 44.5°C at the change-over of acclimation temperature from 20 to 35°C. Lizards acclimated to the three constant temperatures also differed in the range of viable body temperatures; the range was widest in the 25°C treatment (38.1°C) and narrowest in the 35°C treatment (36.5°C), with the 20°C treatment in between (37.2°C). The results of this study show that local thermal conditions do not have a fixed influence on thermal preference and thermal tolerance in T. septentrionalis.     

泽陆蛙和饰纹姬蛙蝌蚪不同热驯化下选择体温和热耐受性

用泽陆蛙（Fejervarya limnocharis）蝌蚪和饰纹姬蛙（Microhyla ornata）蝌蚪做研究模型,检测热驯化（20 、25 和30 C）对选择体温（Tsel）、低温耐受性（CTMin）和高温耐受性（CTMax）的影响。结果显示,两种蝌蚪的Tsel既不受驯化温度的影响,也不存在种间差异;泽陆蛙蝌蚪的CTMin显著小于饰纹姬蛙蝌蚪,而CTMax和VTR则显著大于饰纹姬蛙蝌蚪;CTMin和CTMax随驯化温度的升高而升高,VTR则随驯化温度的升高而减小。研究结果表明,热驯化显著影响两种蝌蚪的CTMin、CTMax和VTR,而对两种蝌蚪的体温调定点无显著影响;这些热生物学特征对两种蝌蚪有效适应环境温度变化、利用资源、减少种间竞争具有重要的生态学意义。     

Ontogenetic shifts in thermal tolerance, selected body temperature and thermal dependence of food assimilation and locomotor performance in a lacertid lizard, Eremias brenchleyi

We used Eremias brenchleyi as a model animal to examine differences in thermal tolerance, selected body temperature, and the thermal dependence of food assimilation and locomotor performance between juvenile and adult lizards. Adults selected higher body temperatures (33.5 vs. 31.7 degrees C) and were able to tolerate a wider range of body temperatures (3.4-43.6 vs. 5.1-40.8 degrees C) than juveniles. Within the body temperature range of 26-38 degrees C, adults overall ate more than juveniles, and food passage rate was faster in adults than juveniles. Apparent digestive coefficient (ADC) and assimilation efficiency (AE) varied among temperature treatments but no clear temperature associated patterns could be discerned for these two variables. At each test temperature ADC and AE were both higher in adults than in juveniles. Sprint speed increased with increase in body temperature at lower body temperatures, but decreased at higher body temperatures. At each test temperature adults ran faster than did juveniles, and the range of body temperatures where lizards maintained 90% of maximum speed differed between adults (27-34 degrees C) and juveniles (29-37 degrees C). Optimal temperatures and thermal sensitivities differed between food assimilation and sprint speed. Our results not only show strong patterns of ontogenetic variation in thermal tolerance, selected body temperature and thermal dependence of food assimilation and locomotor performance in E. brenchleyi, but also add support for the multiple optima hypothesis for the thermal dependence of behavioral and physiological variables in reptiles.     

Effect of Body Size on Reef Fish Tolerance to Extreme Low and High Temperatures

Understanding the thermal physiology of tropical marine organisms has become an issue of major interest due to the potential impact of current global changes in temperature. In this study we report the effect of body size on the thermal tolerance (as critical thermal maximum (CTMax) and minimum (CTMin)) of seven reef fish species from Gorgona Island (tropical eastern Pacific Ocean). Within the studied species we found little variation in CTMax and CTMin among fishes ranging from juveniles to adults. This suggests that thermal tolerance of small tropical reef fishes is not significantly affected by differences in body size. The reduced intra-specific variation in thermal tolerance found in these species also suggests a limited capability to adapt to extreme thermal conditions and raises concerns regarding current global changes in temperature.     

Thermal biology and locomotor performance of the Andean lizard Liolaemus fitzgeraldi (Liolaemidae) in Argentina

Ectotherms thermoregulate to maintain their body temperature within the optimal range needed for performing vital functions. The effect of climate change on lizards has been studied as regards the sensitivity of locomotor performance to environmental temperatures. We studied thermoregulatory efficiency and locomotor performance for Liolaemus fitzgeraldi in the Central Andes of Argentina. We determined body temperature, micro-environmental temperatures and operative temperatures in the field. In the laboratory, we measured preferred temperatures and calculated the index of thermoregulatory efficiency. We estimated the thermal sensitivity of locomotion by measuring sprint speed (initial velocity and long sprint) and endurance at five different body temperatures. Body temperature was not associated with either micro-environmental temperature, nor did it show differences with preferred temperatures. Thermoregulatory efficiency was moderate (0.61). Initial velocity and long sprint trials showed differences at different temperatures; however, endurance did not. Moreover, the optimal temperatures for the performance trials showed no significant differences among themselves. We conclude that Liolaemus fitzgeraldi has thermal sensitivity in locomotor performance with respect to body temperature and that it is an eurythermic lizard that experiences a large variation in body temperature and that has thermal flexibility in the cold.     

Critical thermal maxima and minima of Macrobrachium rosenbergii (Decapoda: Palaemonidae)

1. Critical thermal maxima (CTMax) and minima (CTMin) were determined for postlarvae and juveniles of Macrobrachium rosenbergii acclimated at 20, 23, 26, 29 and 32±1°C. 2. At each acclimation temperature the CTMax and CTMin for postlarvae were 37.3, 38.3, 39.0, 41.0, 41.6°C and 10.0, 11.0, 13.0, 14.8, 16.8°C respectively and for juveniles 36.5, 38.4, 39.2, 41.5, 42.0 and 10.5, 11.3, 13.3, 14.6, 16.4°C respectively. 3. We found no indication of significant differences (P>0.05) in the CTMax and CTMin of the prawn postlarvae and juveniles. 4. The zone of thermal tolerance base on the CTMax and CTMin boundaries for postlarvae was 821.2°C² and 816.9°C² for juveniles, showing a high degree of eurythermality. To cultivate this species it should be done in no less than 16°C (CTMin) and below 42°C.     

EVOLUTION OF SPRINT SPEED IN LACERTID LIZARDS: MORPHOLOGICAL,PHYSIOLOGICAL, AND BEHAVIORAL COVARIATION

Organismal performance abilities occupy a central position in phenotypic evolution; they are determined by suites of interacting lower-level traits (e.g., morphology and physiology) and they are a primary focus of natural selection. The mechanisms by which higher levels of organismal performance are achieved during evolution are therefore fundamentally important for understanding correlated evolution in general and coadaptation in particular. Here we address correlated evolution of morphological, physiological, and behavioral characteristics that influence interspecific variation in sprint speed in a clade of lacertid lizards. Phylogenetic analyses using independent contrasts indicate that the evolution of high maximum sprinting abilities (measured on a photocell-timed racetrack) has occurred via the evolution of (1) longer hind limbs relative to body size, and (2) a higher physiologically optimum temperature for sprinting. For ectotherms, which experience variable body temperatures while active, sprinting abilities in nature depend on both maximum capacities and relative performance levels (i.e., percent of maximum) that can be attained. With respect to temperature effects, relative performance levels are determined by the interaction between thermal physiology and thermoregulatory behavior. Among the 13 species or subspecies of lizards in the present study, differences in the optimal temperature for sprinting (body temperature at which lizards run fastest) closely matched interspecific variation in median preferred body temperature (measured in a laboratory photothermal gradient), indicating correlated evolution of thermal physiology and thermal preferences. Variability of the preferred body temperatures maintained by each species is, across species, negatively correlated with the thermal-performance breadth (range of body temperatures over which lizards can run relatively fast). This pattern leads to interspecific differences in the levels of relative sprint speed that lizards are predicted to attain while active at their preferred temperatures. The highest levels of predicted relative performance are achieved by species that combine a narrow, precise distribution of preferred temperatures with the ability to sprint at near-maximum speeds over a wide range of body temperatures. The observed among-species differences in predicted relative speed were positively correlated with the interspecific variation in maximum sprinting capacities. Thus, species that attain the highest maximum speeds are (1) also able to run at near-maximum levels over a wide range of temperatures and (2) also maintain body temperatures within a narrow zone near the optimal temperature for sprinting. The observed pattern of correlated evolution therefore has involved traits at distinct levels of biological organization, that is, morphology, physiology, and behavior; and trade-offs are not evident. We hypothesize that this particular trait combination has evolved in response to coadaptational selection pressures. We also discuss our results in the context of possible evolutionary responses to global climatic change.     

Thermal tolerance of European Sea Bass (Dicentrarchus labrax) juveniles acclimated to three temperature levels

This study was carried out to determine upper (CTMax) and lower (CTMin) thermal tolerance, acclimation response ratio (ARR) and thermal tolerance polygon of the European sea bass inhabiting the Iskenderun Bay, the most southeasterly part of the Mediterranean Sea, at three acclimation temperatures (15, 20, 25 °C). Acclimation temperature significantly affected the CTMin and CTMax values of the fish. At 0.3 °C min⁻¹ cooling or heating rate, CTMin ranged from 4.10 to 6.77 °C and CTMax ranged from 33.23 to 35.95 °C in three acclimation temperatures from 15 to 25 °C. Thermal tolerance polygon for the juveniles at the tested acclimation temperatures was calculated to be 296.14 °C². In general, the current data show that our sea bass population possesses acclimation response ratio (ARR) values (0.25-0.27) similar to some tropical species. The cold tolerance values attained for this species ranged from 4.10 to 6.77 °C, suggesting that cold winter temperatures may not pose danger during the culture of European sea bass in deep ponds or high water exchange rate systems. Upper thermal tolerance is more of a problem in the southern part of the Mediterranean as maximum water temperature in ponds may sometimes exceed 33-34 °C, during which underground cool-water should be used to lower ambient water temperature in the mid-summer. For successful culture of sea bass in ponds, temperature should be maintained around 25 °C throughout the year and this can be managed under greenhousing systems using underground well-waters, commonly available in the region.     

Sex-based differences and similarities in locomotor performance, thermal preferences, and escape behaviour in the lizard Platysaurus intermedius wilhelmi

Differences between sexes in physiological performance have received little attention in animals. We tested for sex differences in maximum sprint speed and maximal exertion over a range of temperatures in a population of Platysaurus intermedius wilhelmi lizards. We also examined sex-based differences in selected temperature range, mean field body temperatures (T(b)), and thermal activity limits. Finally, we conducted field studies to quantify male and female responses to a potential predator, which may be affected by their respective performance capabilities. Males were faster than females at all temperatures, and body size had no significant effect on sprint speeds. Males and females also selected similar T(b)'s when placed in a thermal gradient, but in the field, male lizards' T(b)'s were different from those of the females. However, predicted sprint speeds for males and females at their field T(b)'s are similar. No significant differences were found between males and females with regard to maximal exertion. When approached in the field, adult male lizards took refuge significantly earlier than did adult females and also fled over shorter distances, suggesting that females rely on crypsis as an escape strategy.