METABOLIC RATE AND ITS TEMPERATURE-ADAPTIVE SIGNIFICANCE IN SIX GEOGRAPHIC RACES OF PEROMYSCUS

1965 ◽  
Vol 43 (2) ◽  
pp. 309-323 ◽  
Author(s):  
J. S. Hayward

The metabolic rate characteristics of six races of Peromyscus, selected from a wide range of habitats, have been determined over the temperature range 0° to 35 °C. After acclimation to standardized laboratory conditions, critical temperatures and metabolic responses to temperatures below thermoneutrality were largely a function of body size: the larger the mouse, the greater its thermoregulatory efficiency. Body size per se is not correlated with the gross climate of the respective habitats. A single equation which predicts the metabolic rate of these races at any temperature between 0° and 27 °C, from a knowledge of body weight and body temperature, is derived.When considered as a single group, the basal oxygen consumption of all races varied with body weight0,60 over the body weight range of 14.7 to 36.0 g and was insignificantly different from the accepted interspecies approximation. The basal metabolic rates of each race showed no temperature-adaptive differences, especially when considered in relation to body composition. It is concluded that basal metabolic rate is nonadaptive to climate in these races of Peromyscus and consequently has played no important part in their distribution and speciation.

1971 ◽  
Vol 55 (3) ◽  
pp. 651-665 ◽  
Author(s):  
G. M. HUGHES ◽  
R. GAYMER ◽  
MARGARET MOORE ◽  
A. J. WOAKES

1. The O2 consumption and CO2 release of nine giant tortoises Testudo gigantea (weight range 118 g-35·5 kg) were measured at a temperature of about 25·5°C. Four European tortoises Testudo hermanni (weight range 640 g-2·16 kg) were also used. The mean RQ values obtained were 1·01 for T. gigantea and 0·97 for T. hermanni. These values were not influenced by activity or size. 2. The data was analysed by plotting log/log regression lines relating body weight to O2 consumption. Both maximum and minimum metabolic rates recorded for each individual T. gigantea showed a negative correlation with body weight. For active rates the relation was O2 consumption = 140·8W0·97, whereas for inactive animals O2 consumption = 45·47W0·82. 3. The maximum rates were obtained from animals that were observed to be active in the respirometer and the minimum rates from animals that remained quiet throughout. The scope for activity increased with body size, being 82 ml/kg/h for animals of 100 g and 103 ml/kg/h for 100 kg animals. The corresponding ratio between maximum and minimum rates increases from about 2 to 6 for the same weight range. 4. Values for metabolic rate in T. hermanni seem to be rather lower than in T. gigantea. Analysis of the relative proportion of the shell and other organs indicates that the shell forms about 31% of the body weight in adult T. hermanni but only about 18% in T. gigantea of similar size. The shell is not appreciably heavier in adult T. gigantea (about 20%). 5. Data obtained for inactive animals is in good agreement with results of other workers using lizards and snakes. Previous evidence suggesting that chelonians show no reduction in metabolic rate with increasing size is not considered to conflict with data obtained in the present work.


Author(s):  
R. C. Newell ◽  
V. I. Pye

INTRODUCTIONA considerable amount of data now exists on the relationship between metabolism and body size in a wide range of organisms from bacteria and protozoans through to large mammals. Much of this information has been reviewed by Kleiber (1932, 1947), Brody and Procter (1932), Brody (1945), Zeuthen (1947, 1953), Hemmingsen (1950, i960) and Bertalanffy (1957). In general the metabolism has been shown to be proportional to a fractional power of the body weight thus eggs, the larger metazoan poikilotherms and even homoiotherms is proportional to a constant power of the body weight. This factor has been shown to be 0.751 ± 0.015 by Hemmingsen (i960). Superimposed upon this general relationship are variations according to the weight range of the organisms concerned. Thus both Zeuthen (1953) and Hemmingsen (i960) have shown that the value of the constant b for unicellular organisms is approximately 0.7 (Zeuthen, 1953) or 0.751 (Hemmingsen, 1960), whilst that for small metazoans is 0.95 (Zeuthen, 1953) or 1.0 (Hemmingsen, 1960). Finally, the slope of the line relating the metabolism to body size in larger metazoans is 075 (Zeuthen, 1953) or 0.751 (Hemmingsen, 1960). That is, the value for b — 1 in equation (2) is likely to be between -0.3 and -0.249 in unicellular organisms; 0 and -0.05 in small metazoans and approximately -0.249 in larger metazoans.Despite this apparently fundamental relationship between metabolism and body size, there are many instances where for a particular species the relationship may not apply. Indeed in some species the metabolism may vary in its relationship to body weight according to conditions such as salinity, shore level, experimental temperature and acclimation temperature.


2020 ◽  
Author(s):  
Yu_an Zhang ◽  
Zijie Sun ◽  
Chen Zhang ◽  
Shujun Yin ◽  
Wenzhi Wang ◽  
...  

Abstract In stock farming, the body size parameters and weight of yaks can reasonably reflect the growth and development characteristics, production performance and genetic characteristics of yaks. However, it is difficult for herders to measure the body size and weight of yaks by traditional manual methods. Fortunately, with the development of edge computing, herders can use mobile devices to estimate the yak’s body size and weight. The purpose of this paper is to provide a machine vision-based yak weight estimation method for the edge equipment and establish a yak estimation comprehensive display system based on the user’s use of the edge equipment in order to maximize the convenience of herdsmen’s work. In our method, a set of yak image foreground extraction and measurement point recognition algorithm suitable for edge equipment were developed to obtain yak’s measurement point recognition image, and the ratio between body sizes was transmitted to the cloud server. Then, the body size and weight of yaks were estimated using the data mining method, and the body size estimation data were constantly displayed in the yak estimation comprehensive display system. 25 yaks in different age groups were randomly selected from the herd to perform experiments. The experimental results show that the foreground extraction method can obtain segmentation image with good boundary, and the yak measurement point recognition algorithm has good accuracy and stability. The average error between the estimated values and the actual measured values of body height, oblique length, chest depth, cross height and body weight is 1.95%, 3.11%, 4.91%, 3.35% and 7.79%, respectively. Compared with the traditional manual measurement method, the use of mobile end to estimate the body size and weight of yaks can improve the measurement efficiency, facilitate the herdsmen to breed yaks, reduce the stimulation of manual measurement on yaks, and lay a solid foundation for the fine breeding of yaks in Sanjiangyuan region.


2014 ◽  
Vol 10 (6) ◽  
pp. 20140261 ◽  
Author(s):  
John P. DeLong

The parameters that drive population dynamics typically show a relationship with body size. By contrast, there is no theoretical or empirical support for a body-size dependence of mutual interference, which links foraging rates to consumer density. Here, I develop a model to predict that interference may be positively or negatively related to body size depending on how resource body size scales with consumer body size. Over a wide range of body sizes, however, the model predicts that interference will be body-size independent. This prediction was supported by a new dataset on interference and consumer body size. The stabilizing effect of intermediate interference therefore appears to be roughly constant across size, while the effect of body size on population dynamics is mediated through other parameters.


1956 ◽  
Vol 186 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Max Kleiber ◽  
Arthur H. Smith ◽  
Theodore N. Chernikoff

On the basis of 926 respiration trials, metabolic rates of normal female rats are presented as means of 42 different age groups from birth to 1000 days of age. The means with their standard errors are given for the metabolic rates per rat, per kilogram weight, per unit of the 2/3 power of body weight (surface), and per unit of the 3/4 power of body weight (inter specific unit of metabolic body size). A minimum of 72.6 Cal/kg.3/4 occurs between the ages of 200 and 300 days. An equation with two exponentials predicts the metabolic rate of rats from 77–1000 days of age with a standard deviation between prediction and observation of 2.2% of the mean.


Paleobiology ◽  
2013 ◽  
Vol 39 (1) ◽  
pp. 109-122 ◽  
Author(s):  
Douglas S. Glazier ◽  
Matthew G. Powell ◽  
Travis J. Deptola

We infer the body-size scaling slope of metabolic rate in a trilobite by applying a cell-size model that has been proposed to explain metabolic scaling in living organisms. This application is especially tractable in fossil arthropods with well-preserved compound eyes because the number and size of eye facets appear to be useful proxies for the relative number and size of cells in the body. As a case study, we examined the ontogenetic scaling of facet size and number in a ∼390-Myr-old local assemblage of the trilobite Eldredgeops rana, which has well-preserved compound eyes and a wide body-size range. Growth in total eye lens area resulted from increases in both facet area and number in relatively small (presumably young) specimens, but only from increases in facet area in large (presumably more mature) specimens. These results suggest that early growth in E. rana involved both cell multiplication and enlargement, whereas later growth involved only cell enlargement. If the cell-size model is correct, then metabolic rate scaled allometrically in E. rana, and the scaling slope of log metabolic rate versus log body mass decreased from ∼0.85 to 0.63 as these animals grew. This inferred age-specific change in metabolic scaling is consistent with similar changes frequently observed in living animals. Additional preliminary analyses of literature data on other trilobites also suggest that the metabolic scaling slope was <1 in benthic species, but ∼1 in pelagic species, as has also been observed in living invertebrates. The eye-facet size (EFS) method featured here opens up new possibilities for examining the bioenergetic allometry of extinct arthropods.


1977 ◽  
Vol 43 (1) ◽  
pp. 126-132 ◽  
Author(s):  
J. E. Greenleaf ◽  
E. M. Bernauer ◽  
L. T. Juhos ◽  
H. L. Young ◽  
J. T. Morse ◽  
...  

To determine the cause of the body weight loss during bed rest (BR), fluid balance and anthropometric measurements were taken from seven men (19–21 yr) during three 2-wk BR periods which were separated by 3-wk ambulatory recovery periods. Caloric intake was 3,073 +/- 155 (SD) kcal/day. During two of the three BR periods they performed supine isotonic exercise at 68% of VO2max on the ergometer for 1 h/day; or supine isometric exercise at 21% of maximal leg extension force for 1 min followed by a 1-min rest for 1 h/day. No prescribed exercise was given during the other BR period. During BR, body weight decreased slightly with no exercise (-0.43 kg, NS), but decreased significantly (P less than 0.05) by -0.91 kg with isometric and by -1.77 kg with isotonic exercise. About one-third of the weight reduction with isotonic exercise was due to fat loss (-0.69 kg) and, the remainder, to loss of lean body mass (-0.98 kg). It is concluded that the reduction in body weight during bed rest has two major components: First, a loss of lean body mass caused by assumption of the horizontal body position that is independent of the metabolic rate. Second, a loss of body fat content that is proportional to the metabolic rate.


1956 ◽  
Vol 186 (2) ◽  
pp. 207-210 ◽  
Author(s):  
M. C. Conrad ◽  
A. T. Miller

The interrelations of body size, body composition and basal metabolism were studied in 69 albino rats ranging in age from 18–174 days. The decline in metabolic rate with age was more rapid than would be predicted from the weight0.75 rule which eliminates the influence of body size in interspecific measurements. Body composition analyses indicated that the increase with age in metabolically inert fat and bone minerals was approximately balanced by a corresponding decrease in metabolically inert extracellular fluid, so that ‘active tissue mass’ was virtually unchanged. Calculations based on data in the literature indicate that about one-half the decline in metabolic rate with age may be due to the corresponding decrease in the relative weight of the viscera. The remainder of the decline in metabolic rate must be due to factors other than changes in the chemical or histological composition of the body.


1931 ◽  
Vol 54 (6) ◽  
pp. 789-800 ◽  
Author(s):  
Charlotte Purdy ◽  
Charles Sheard

High metabolic rates are associated normally with small differences of electric potential, whereas low metabolic rates are associated with large differences of electric potential as measured on the extremities of the body. Within the normal range of metabolism there appears to be a definite correlation between the metabolic rates and the difference of electric potential over a specified area of the skin, provided the person under test has no abnormalities of the circulatory system or of the functions of the skin. If there are no dysfunctions of the circulation or of the skin, the metabolic rate may be calculated, within ±4 points, from the expression See PDF for Equation where x is the metabolic rate and y is the difference of electric potential across the specified areas of skin (electrodes 12 cm. apart). In general, there are abnormalities of the circulation of the blood or of the functions of the skin of persons for whom the metabolic rates determined by the two methods (difference of electric potentials and gasometric procedures) do not agree with ±4 points. Manifest retardation or return to normality in the rate of circulation of the blood, such as may be produced by the sphygmomanometric cuff under varying pressures, produces marked changes in the difference of electric potentials obtained across a specified intervening area of skin. Retardation of flow of blood produces increased differences of electric potential. Preliminary investigations indicate that there is an inverse correlation between cutaneous temperatures and differences of electric potential. Day by day variations, emotive effects and the partaking of food have less effect, in general, on the electric potentials across a specified area of skin than they have on the metabolic rates. These experimental results indicate that there may be a more direct correlation between electric potentials and the circulation of the blood per se than between electric potentials and the metabolism of the body per se. When normality of circulation of the blood and of the functions of the skin exists in the areas under test for differences of electric potential, there is apparently a correlation between metabolic rates and electric potentials.


2011 ◽  
Vol 278 (1721) ◽  
pp. 3135-3141 ◽  
Author(s):  
Montserrat Gomendio ◽  
Maximiliano Tourmente ◽  
Eduardo R. S. Roldan

The hypothesis that sperm competition should favour increases in sperm size, because it results in faster swimming speeds, has received support from studies on many taxa, but remains contentious for mammals. We suggest that this may be because mammalian lineages respond differently to sexual selection, owing to major differences in body size, which are associated with differences in mass-specific metabolic rate. Recent evidence suggests that cellular metabolic rate also scales with body size, so that small mammals have cells that process energy and resources from the environment at a faster rate. We develop the ‘metabolic rate constraint hypothesis’ which proposes that low mass-specific metabolic rate among large mammals may limit their ability to respond to sexual selection by increasing sperm size, while this constraint does not exist among small mammals. Here we show that among rodents, which have high mass-specific metabolic rates, sperm size increases under sperm competition, reaching the longest sperm sizes found in eutherian mammals. By contrast, mammalian lineages with large body sizes have small sperm, and while metabolic rate (corrected for body size) influences sperm size, sperm competition levels do not. When all eutherian mammals are analysed jointly, our results suggest that as mass-specific metabolic rate increases, so does maximum sperm size. In addition, species with low mass-specific metabolic rates produce uniformly small sperm, while species with high mass-specific metabolic rates produce a wide range of sperm sizes. These findings support the hypothesis that mass-specific metabolic rates determine the budget available for sperm production: at high levels, sperm size increases in response to sexual selection, while low levels constrain the ability to respond to sexual selection by increasing sperm size. Thus, adaptive and costly traits, such as sperm size, may only evolve under sexual selection when metabolic rate does not constrain cellular budgets.


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