A review of the effects of temperature on the oxygen consumption of intertidal gastropods

A multiple regression analysis has been used to relate oxygen consumption, body weight, and temperature, for 8 species of gill-bearing intertidal gastropods. Using a standard sized animal, the oxygen consumption of the snails in sea water at each temperature is very similar and the analysis gives a Q₁₀ of 2.1. In air the mid and high shore species have similar rates of oxygen consumption to those in water and a Q₁₀ of 2.2. The low shore species show lower values for both aerial oxygen consumption and Q₁₀. Similar patterns have been found in a further 20 species.     

Effects of incubation temperature on the energetics of embryonic development and hatchling morphology in the Brisbane river turtle Emydura signata

Incubation temperature and the amount of water taken up by eggs from the substrate during incubation affects hatchling size and morphology in many oviparous reptiles. The Brisbane river turtle Emydura signata lays hard-shelled eggs and hatchling mass was unaffected by the amount of water gained or lost during incubation. Constant temperature incubation of eggs at 24 °C, 26 °C, 28 °C and 31 °C had no effect on hatchling mass, yolk-free hatchling mass, residual yolk mass, carapace length, carapace width, plastron length or plastron width. However, hatchlings incubated at 26 °C and 28 °C had wider heads than hatchlings incubated at 24 °C and 31 °C. Incubation period varied inversely with incubation temperature, while the rate of increase in oxygen consumption during the first part of incubation and the peak rate of oxygen consumption varied directly with incubation temperature. The total amount of oxygen consumed during development and hatchling production cost was significantly greater at 24 °C than at 26 °C, 28 °C and 31 °C. Hatchling mass and dimensions and total embryonic energy expenditure was directly proportional to initial egg mass. Accepted: 18 March 1998     

Paradoxical social effects on response to cold during ontogeny of the common white-toothed shrew,Crocidura russula

Summary Postnatal development of thermoregulatory responses to cold differs between shrews measured singly or in groups as a litter. Single shrews increase their metabolic response to cold within 14 days to maintain normothermia. Shrews measured in groups show little or no metabolic response to cold and do not reach normothermia before the 19th day. Lower body temperatures in groups are explained by torpor, which obviously needs the prerequisite of forming a group. Oxygen consumption of the singly measured shrews depends upon body mass.     

The magnitude of the temperature-driven contribution to within-plant transport

Abstract The contribution from temperature gradients within a plant to convective transport is calculated. Its magnitude depends primarily on the temperature differences in the plant and the radius of the conducting elements; the other quantities affecting it are well-established physical constants. Assuming a temperature difference in the plant of 1 K and a conductive element radius of 10^?4 m, the speed of convective flow is 0.5 cm h^?1 and this is independent of distance.     

Uphill transport of water by electroosmosis

Summary Lepismatidae are able to gain water from subsaturated atmosphere above a relative humidity of 45%, surmounting a water potential difference of at least 1.1×10⁸ Pa (1,100 bar). This extraordinary task is performed by the monolayered epithelium of the posterior rectum. The particle coat of the folded apical membrane of this epithelium suggests the presence of the electrogenic, lumen-directed cation transport, which is commonly found in insects. Assuming this kind of transport and considering the anatomy of the organ, a working hypothesis for this hyposmotic water transport has been developed: The electrogenic cation transport maintains the circulation of the transported ion species across the apical membrane; the voltagedriven inward current transfers water by electroosmosis against its chemical potential from the extracellular space into the cytoplasm. Voltage and current measurements and synchronous measurements of water flow across the epithelium of the posterior rectum ofLepisma saccharina strongly corroborate this hypothesis. The transepithelial voltage is up to 200 mV (lumen positive); the short-circuit current averages 200 A per cm² of the epithelium. Both depend acutely on oxidative metabolism as does spontaneous water uptake. Exogenous transepithelial current (I) induces, independently of anoxia, a proportional change in volume flow (J _v). The induced flow has the direction of the cation flow. Its mean coupling ratio (J _v/I) is 1.5×10^–9m³/A·sec corresponding to 7 to 8 H₂O per positive unit charge. Critical evaluation of experimental data reveals that water uptake by electroosmosis may quantitatively account forin vivo performance without requiring any unusual assumption.     

The effects of temperature changes on the oxygen consumption of juvenile Chinese shrimp Fenneropenaeus chinensis Osbeck

The effects of temperature changes on oxygen consumption of Chinese shrimp (Fenneropenaeus chinensis Osbeck) were studied. The response of oxygen consumption to a temperature rise was conformed to partial metabolic compensation. No compensatory response was observed at lower temperature. A sudden temperature increase by 12 °C resulted an overshoot in oxygen consumption in shrimp adapted to 19 °C, while a sudden decrease by 12 °C in shrimp adapted to 19 °C resulted in an undershoot in oxygen consumption. The shrimp adapted to 31 °C responded with an undershoot in oxygen consumption when a sudden temperature drop by 12 °C occurred. But overshoot in oxygen consumption did not occur when the shrimps were transferred back from 19 to 31 °C. The amplitude of oxygen consumption was reduced in shrimp during the process of acclimation to the temperature diel fluctuation. After the shrimp had adapted to the temperature fluctuation, the daily mean oxygen consumption of shrimp at diel temperature fluctuation from 24 to 30 °C was significantly lower than those adapted to the constant temperature at 27 °C (P<0.05). The decrease in metabolic rate may account for the increase in the growth rate of shrimp at a diel fluctuating thermal regime.     

Temperature and the energetics of development in the house cricket (Acheta domesticus)

The influence of rearing temperature on the energetics of development was investigated in house crickets (Acheta domesticus). Crickets raised at 25 degrees C grew slower (0.51 mg d(-1), dry mass basis) and took longer to develop (119 d) but obtained a greater adult body mass (61 mg, dry mass) than crickets reared at 28 degrees C (0.99 mg d(-1), 49 d, 48 mg). Total metabolic energy consumed during development at 25 degrees C (1351 J) was twice that at 28 degrees C (580 J) primarily because of the longer development period, and as a consequence the specific net cost of growth was much greater for crickets reared at 25 degrees C (22.1 kJ g(-1)) than 28 degrees C (11.9 kJ g(-1)).     

Rheological modelling of physiological variables during temperature variations at rest

The evolution with time of cardio-respiratory variables, blood pressure and body temperature has been studied on six males, resting in semi-nude conditions during short (30 min) cold stress exposure (0°C) and during passive recovery (60 min) at 20°C. Passive cold exposure does not induce a change inHR but increasesVO₂,VCO₂Ve and core temperatureT_re, whereas peripheral temperature is significantly lowered. The kinetic evolution of the studied variables was investigated using a Kelvin-Voigt rheological model. The results suggest that the human body, and by extension the measured physiological variables of its functioning, does not react as a perfect viscoelastic system. Cold exposure induces a more rapid adaptation for heart rate, blood pressure and skin temperatures than that observed during the rewarming period (20°C), whereas respiratory adjustments show an opposite evolution. During the cooling period of the experiment the adaptative mechanisms, taking effect to preserve core homeothermy and to obtain a higher oxygen supply, increase the energy loss of the body.     

The environmental effects of salinity and temperature on the oxygen consumption and total body osmolality of the marine flatworm Procerodes littoralis

The present study examined the effect of salinity and temperature on the rate of oxygen consumption and total body osmolality of the triclad turbellarian Procerodes littoralis, a common marine flatworm normally found in areas where freshwater streams run out over intertidal areas. Extremes in environmental factors encountered by P. littoralis were recorded at the study site. These were salinity (0-44 psu), temperature (2.7-24.9 °C) and oxygen concentration (2.8-16.1 mg l⁻¹). Respirometry experiments showed minimal oxygen consumption rates at the salinity extremes encountered by the study species (0 and 40 psu). Further experiments showed relatively constant oxygen consumption rates over the temperature range 5-20 °C and elevated consumption rates at temperatures above 25 °C. Total body osmolality of P. littoralis increased with increasing salinity. The study illustrates how a marine flatworm uses integrated physiological and behavioural mechanisms to successfully inhabit an environment that is predominantly freshwater for up to 75% of the tidal cycle.     

Oxygen consumption and body temperature of active and resting honeybees

We measured the energy turnover (oxygen consumption) of honeybees (Apis mellifera carnica), which were free to move within Warburg vessels. Oxygen consumption of active bees varied widely depending on ambient temperature and level of activity, but did not differ between foragers (>18 d) and middle-aged hive bees (7-10 d). In highly active bees, which were in an endothermic state ready for flight, it decreased almost linearly, from a maximum of 131.4 microl O(2) min(-1) at 15 degrees C ambient temperature to 81.1 microl min(-1) at 25 degrees C, and reached a minimum of 29.9 microl min(-1) at 40 degrees C. In bees with low activity, it decreased from 89.3 microl O(2) min(-1) at 15 degrees C to 47.9 microl min(-1) at 25 degrees C and 14.7 microl min(-1) at 40 degrees C. Thermographic measurements of body temperature showed that with increasing activity, the bees invested more energy to regulate the thorax temperature at increasingly higher levels (38.8-41.2 degrees C in highly active bees) and were more accurate. Resting metabolism was determined in young bees of 1-7 h age, which are not yet capable of endothermic heat production with their flight muscles. Their energy turnover increased from 0.21 microl O(2) min(-1) at 10 degrees C to 0.38 microl min(-1) at 15 degrees C, 1.12 microl min(-1) at 25 degrees C, and 3.03 microl min(-1) at 40 degrees C. At 15, 25 and 40 degrees C, this was 343, 73 and 10 times below the values of the highly active bees, respectively. The Q(10) value of the resting bees, however, was not constant but varied in a U-shaped manner with ambient temperature. It decreased from 4.24 in the temperature range 11-21 degrees C to 1.35 in the range 21-31 degrees C, and increased again to 2.49 in the range 30-40 degrees C. We conclude that attempts to describe the temperature dependence of the resting metabolism of honeybees by Q(10) values can lead to considerable errors if the measurements are performed at only two temperatures. An acceptable approximation can be derived by calculation of an interpolated Q(10) according to the exponential function (V(O(2))=0.151 x 1.0784(T(a))) (interpolated Q(10)=2.12).     

Effect of temperature on electron transport activities of glutaraldehyde-fixed pea thylakoids

Temperature-induced changes in Hill activity of glutaraldehyde-fixed pea ( Pisum sativum L. cv. Alaska) thylakoids have been examined. Using ferricyanide as electron acceptor, a temperature-induced change occurred at ca 12–14°C for both control and fixed thylakoids. In contrast to the controls, fixed thylakoids not only showed a change in slope of the Arrhenius plots but also a discontinuity which has not been observed in previous studies. A drop in activity coincided with the decrease in slope: the extent of the reduction depended on the concentration of glutaraldehyde used for fixation. Using a lipophilic electron acceptor, a temperature-induced change also occurred at 12–14°C, but there was no reduction in activities of fixed thylakoids at temperatures above the change in slope.
The results indicate that a temperature-induced change in fixed thylakoids restricts the access of ferricyanide to its reductant(s) in the membrane but that fixation does not affect the temperature-induced change per se. The results confirm that temperature has a general effect on the functioning of thylakoid membranes. The data demonstrate that calculations of the extent of inhibition by glutaraldehyde of Hill activity with ferricyanide should take into account the temperature at which assays are performed.     

The effects of solar radiation and nutrient solution temperature on the uptake of oxygen by submerged roots of mature tomato plants

Summary A statistical analysis of data on oxygen uptake by submerged roots of mature tomato plants, from a nutrient solution containing sufficient oxygen, has demonstrated that variations in oxygen uptake are positively related to variations in solar radiaton, particularly at radiation levels below 2.0 MegaJoules.h⁻¹.m⁻². Above this level, however, anegative relationship is indicated, suggesting that intense solar radiation reduces the ability of plant roots to obtain sufficient oxygen for optimum growth processes. It also appears that there is atime lag of about one to two hours between the effects of solar radiation on oxygen uptake. Greenhouse air temperature is positively correlated with radiation, with little or no time lag, and variations in greenhouse air temperature effect variations in solution temperature with a time lag of 2 to 3 hours. Greenhouse air temperature affects respiration in the submerged roots indirectly, with a 1 to 2 hour lag, by effecting the nutrient solution temperature, and possibly by affecting the growth processes in thesubaerial roots, which in turn may result, in some way, in increased oxygen uptake by the submerged roots, partly bypassing the restraining effects of lagging nutrient solution temperature. Variations in nutrient solution temperature do not appear to be causally related in effecting variations in oxygen uptake in a major way, probably because a considerable time lag of around 3 hours seems to exist between variations in radiation and solution temperature, in this experiment. As such, radiation and greenhouse air temperature appear to be rather important and dominant variables, effecting changes in oxygen uptake. In addition, the results suggest thatdaytime, variable heating of the nutrient solution, in step with the variations of solar radiation, as well as shading of the tomato crop under conditions of intense solar radiation would likely be beneficial for plant growth and crop production.     

The effects of clothing thermal resistance and operative temperature on human skin temperature

Skin temperature is an essential physiological parameter of thermal comfort. The purpose of this research was to reveal the effects of clothing thermal resistance and operative temperature on local skin temperature (LST) and mean skin temperature (MST). The LSTs (at 32 sites) in stable condition were measured for different clothing thermal resistances 1.39, 0.5 and 0.1 clo. To study the effect of environmental temperature on LST and MST, the LSTs were also measured for operative temperatures 23, 26 and 33 °C. The experimental data showed that the effect of clothing thermal resistance on the foot was greater compared to the other human parts, and the effect of operative temperature on many parts of the human body was great, such as foot, hand, trunk, and arm. The MSTs measured on the conditions that air speed was under 0.1 m/s, RH was about 30–70%, and metabolic rate was about 1 met, were collected from previous studies. On the basis of these experimental data, a MST prediction equation with the operative temperature and clothing thermal resistance as independent variables, was obtained by multiple linear regression. This equation was a good alternative and provided convenience to predict the MST in different operative temperatures and clothing thermal resistances.     

The effects of environmental temperature on the body temperature and ear morphology of the mouse

1. 1.|The external temperatures of the trunks and tails of four groups of mice kept at 33, 21, 8 and 4°C for the first 6 months of their life were different depending on the environmental temperature.

2. 2.|The skin temperatures over the tails was lower than those over the trunk at all ambient temperatures but the internal rectal temperature had not changed.

3. 3.|Those ear pinnae are also important in thermoregulation for those of 33°C mice were larger and thinner than those kept at the lower temperatures.

Differential effects of cobalt on the initiation of fast axonal transport

Effects of Co²⁺ on the fast axonal transport of individual proteins were examined in vitro in bullfrog spinal/sciatic nerves.³⁵S-methionine-labeled proteins, fast-transported in control and Co²⁺-treated preparations were separated via two-dimensional gel electrophoresis. While the overall amount of protein transported was reduced, no qualitative differences could be seen when gel fluorographic patterns were compared. Quantitative analyses of the 48 most abundantly transported species revealed two significantly different populations (p < 0.01) differentially sensitive to Co²⁺ and distinguishable to a large extent by molecular weight. Those proteins less sensitive to Co²⁺ ranged from ~20,000 to 35,000 daltons while those more sensitive to Co²⁺ were >~35,000 daltons. The finding that all proteins are affected by Co²⁺ supports the proposal that fast-transported proteins are subject to a common Co²⁺-sensitive, Ca²⁺-requiring step. The observed differential effects are consistent with more than one Ca²⁺-dependent step occurring during the initiation phase of fast transport.This research was supported by a Muscular Dystrophy Association postdoctoral fellowship to G.C.S., and by research grants from NSF (BNS 79-24125) and the National Multiple Sclerosis Society (RG 1296-A-1) to R.H.     

How incubation temperature influences the physiology and growth of embryonic lizards

Eggs of two small Australian lizards, Lampropholis guichenoti and Bassiana duperreyi, were incubated to hatching at 25 °C and 30 °C. Incubation periods were significantly longer at 25 °C in both species, and temperature had a greater effect on the incubation period of B. duperreyi (41.0 days at 25 °C; 23.1 days at 30 °C) than L. guichenoti (40.1 days at 25 °C; 27.7 days at 30 °C). Patterns of oxygen consumption were similar in both species at both temperatures, being sigmoidal in shape with a fall in the rate of oxygen consumption just prior to hatching. The higher incubation temperature resulted in higher peak and higher pre-hatch rates of oxygen consumption in both species. Total amount of oxygen consumed during incubation was independent of temperature in B. duperreyi, in which approximately 50 ml oxygen was consumed at both temperatures, but eggs of L. guichenoti incubated at 30 °C consumed significantly more (32.6 ml) than eggs incubated at 25 °C (28.5 ml). Hatchling mass was unaffected by either incubation temperature or the amount of water absorbed by eggs during incubation in both species. The energetic production cost of hatchling B. duperreyi (3.52 kJ · g⁻¹) was independent of incubation temperature, whereas in L. guichenoti the production cost was greater at 30 °C (4.00 kJ · g⁻¹) than at 25 °C (3.47 kJ · g⁻¹). Snout-vent lengths and mass of hatchlings were unaffected by incubation temperature in both species, but hatchling B. duperreyi incubated at 30 °C had longer tails (29.3 mm) than those from eggs incubated at 25 °C (26.2 mm). These results indicate that incubation temperature can affect the quality of hatchling lizards in terms of embryonic energy consumption and hatchling morphology. Accepted: 27 January 2000     

The effect of temperature on the velocity of exogenous auxin transport in intact chilling-sensitive and chilling-resistant plants

The velocity of exogenous indol-3yl-acetic acid ([1-¹⁴C]IAA) transport from the apical buds of intact pea, sunflower and cotton plants was determined from 0.5° C to 47° C. The minimum temperature at which transport occurred varied from 2° C (pea and sunflower) to 7° C (cotton). Above these temperatures the velocity of transport increased steadily to maxima near 44° C in all three species. Further increase in temperature resulted in a complete cessation of transport, suggesting a sudden high-temperature breakdown of the auxin transport system. Temperature coefficients (Q₁₀) for transport velocity calculated from Arrhenius plots were low (1.36 to 1.41 between 15° C and 30° C).Arrhenius plots for the chilling-sensitive cotton and sunflower plants exhibited abrupt discontinuities at 14.6° C and 8.7° C respectively. An Arrhenius plot for the chilling-resistant pea exhibited no such discontinuity over the whole temperature range at which transport occurred.Abbreviation IAA indol-3yl-acetic acid     

Effects of ambient PO2 and temperature on oxygen uptake in Nautilus pompilius

This study employs closed-circuit respirometry to evaluate the effect of declining ambient oxygen partial pressure (PO₂) and temperature on mass specific rates of oxygen uptake (V˙O₂) in Nautilus pompilius. At all temperatures investigated (11, 16, and 21 °C), V˙O₂ is relatively constant at high PO₂ (oxyregulation) but declines sharply at low PO₂ (oxyconformation). The critical PO₂ below which oxyconformation begins (P _c) is temperature dependent, higher at 21 °C (49 mmHg) than at 11 °C or 16 °C (21.7 mmHg and 30.8 mmHg respectively). In resting, post-absorptive animals, steady-state resting V˙O₂ increases significantly with temperature resulting in a Q₁₀ value of approximately 2.5. The metabolic strategy of N. pompilius appears well suited to its lifestyle, providing sufficient metabolic scope for its extensive daily vertical migrations, but allowing for metabolic suppression when PO₂ falls too low. The combination of low temperatures and low PO₂ may suppress metabolic rate 16-fold (assuming negligible contributions from anaerobic metabolism and internal O₂ stores), enhancing hypoxia tolerance. Accepted: 20 January 2000     

Gastric evacuation in mackerel: the effects of meal size, prey type and temperature

Gastric evacuation experiments, performed with groups of Atlantic mackerel Scomber scombrus and three different prey species: sprat Sprattus sprattus , sandeel Ammodytes marinus and krill Meganectyphanes norwegicus , revealed a strong temperature effect on gastric evacuation ( Q ₁₀=4.l) and a curvilinear evacuation with a shape intermediate between the square root and the exponential model. From the experiments with krill, where no internal tagging was possible, the medians and upper quartiles of the stomach content distributions were analysed instead of individual data. From these experiments the evacuation rate of krill was 60% higher than that of sandeel. An additional simulation study confirmed that the use of medians results in more accurate estimates of the evacuation rates when compared to the arithmetic means.     

The influence of cold stress and a 36- h fast on the physiological responses to prolonged intermittent walking in man

In a previous study, rectal temperature (T _re) was found to be lower, and oxygen consumption (V˙O₂) and the respiratory exchange ratio (R) were higher in a cold (+5°C), wet and windy environment (COLD), compared with a thermoneutral environment during intermittent walking at ≈30% of peak V˙O₂ (Weller AS, Millard CE, Stroud MA et al. Am J Physiol 272:R226–R233, 1997). The aim of the present study was to establish whether these cold-induced responses are influenced by prior fasting, as impaired thermoregulation has been demonstrated in cold-exposed, resting men following a 48-h fast. To address this question, eight men attempted a 360-min intermittent (15 min rest, 45 min exercise) walking protocol under COLD conditions on two occasions. In one condition, the subjects started the exercise protocol ≈120 min after a standard meal (FED/COLD), whereas in the other the subjects had fasted for 36 h (FASTED/COLD). The first two exercise periods were conducted at a higher intensity (HIGHER, 6 km · h⁻¹ and 10% incline), than the four subsequent exercise periods (LOW, 5 km · h⁻¹ and 0% incline). There was no difference in the time endured in FED/COLD and FASTED/COLD. In FASTED/COLD com pared with FED/COLD, R was lower during HIGHER and LOW, and T _re was lower during LOW, whereas there was no difference in V˙O₂, mean skin temperature and heart rate. Therefore, although the 36-h fast impaired temperature regulation during intermittent low-intensity exercise in the cold, wet and windy environment, it was unlikely to have been the principal factor limiting exercise performance under these experimental conditions. Accepted: 26 August 1997