Metabolic rates and movements of the male tarantula Aphonopelma anax during the mating season

2009 ◽  
Vol 87 (12) ◽  
pp. 1210-1220 ◽  
Author(s):  
T. Stoltey ◽  
C. Shillington

Tarantulas exhibit sexual dimorphism in their resting metabolic rate (RMR). The significantly higher RMRs observed in sexually mature males may be an adaptive strategy to support their higher energetic demands when searching for females. In this study, we investigated how intrasexual differences in male RMR may affect their locomotory activity and behavior during the mating season. Over a 2-year period, we radio-tagged male Texas tan tarantulas ( Aphonopelma anax (Chamberlin, 1940)), measured their movements, and periodically recorded their metabolic rates in an open-flow respirometery system over the course of the breeding season. Differences found in search speed, search-area size, and movement patterns were not sufficiently explained by the small amount of intrasexual variation exhibited in RMR. Individuals were capable of searching areas up to 29 ha and moved up to 365 m/day. In addition, metabolic rate measured over a 24 h period showed no circadian periodicity and remained constant over the season. Lastly, the body condition of new captures stayed constant throughout the season, corroborating observations of males feeding and drinking.

1986 ◽  
Vol 66 (4) ◽  
pp. 937-944 ◽  
Author(s):  
M. OKAMOTO ◽  
J. B. ROBINSON ◽  
R. J. CHRISTOPHERSON ◽  
B. A. YOUNG

Resting and summit metabolic rates were measured in 13 newborn (2.5–15 h old) male Holstein calves exposed to warm and cold tempertures in a water immersion system. Six calves were bottle fed 1 kg of colostrum 30 min before the measurements commenced. In the remaining seven calves, colostrum was withheld until after the end of the measurement period. There were no significant effects of colostrum feeding on resting or summit metabolic rates or the time required for rectal temperature to drop to 35 °C when the calves were immersed in cold water. The time required for rectal temperature to drop to 35 °C increased as the body weight of the calves increased; for each kilogram additional body weight, cooling was delayed for an extra 2.9 min. The resting metabolic rate averaged for both feeding treatments was 2.0 ± 0.1 W kg−1 while mean rectal temperature was 39.1 ± 0.2 °C. Mean summit metabolic rate was 7.2 ± 0.4 W kg−1 and occurred at a mean rectal temperature of 35.4 ± 0.3 °C. The average ratio of the summit to resting metabolic rate was 3.7 ± 0.2. Cooling via water immersion was associated with increases in plasma levels of glucose and free fatty acids. The feeding of 1 kg of colostrum 30 min prior to exposure to acute cold did not improve the apparent resistance of the calves to hypothermia. Key words: Newborn calf, summit metabolism, cold tolerance


2020 ◽  
Vol 158 (5) ◽  
pp. 431-437
Author(s):  
Michael Kam ◽  
Shaher El-Meccawi ◽  
Arieh Brosh ◽  
A. Allan Degen

AbstractSheep are grazers and goats are intermediate feeders. By employing O2 consumption and heart rate measurements, resting metabolic rate (RMR) and field metabolic rate (FMR) were determined in four male fat-tailed Awassi sheep (44.0 ± 3.94) and four male Baladi goats (35.5 ± 5.42 kg) that were co-grazing natural pasture in the Negev Desert. There were 67.7 ± 3.75 g DM/m2 of herbaceous vegetation biomass, which was rapidly becoming senescent and more fibrous. We hypothesized that FMR of these desert-adapted ruminants would be relatively low when compared to other sheep and goat breeds, as animals in arid areas tend to have low metabolic rates. Both sheep (n = 6) and goats (n = 6) foraged 71% of the allotted 11 h free-pasture period; however, sheep grazed more than goats (P < 0.001); whereas goats browsed more than sheep (P < 0.001). RMR was higher (P = 0.007) in sheep than in goats (529 ± 23.5 v. 474 ± 25.4 kJ/kg0.75 BW/d), but FMR did not differ between species (618 ± 55.7 v. 613 ± 115.2 kJ/kg0.75 BW/d). In addition, the cost of activities, as a proportion of FMR, did not differ between sheep and goats; FMR increased by 89 kJ/kg0.75 BW/d or 17% in sheep and by 138 kJ/kg0.75 BW/d or 29% in goats. In comparing FMRs of sheep and goats in this study with these species in other studies, differences were inconsistent and, therefore, our hypothesis was not supported.


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.


2017 ◽  
Vol 4 (12) ◽  
pp. 171359 ◽  
Author(s):  
M. Teague O'Mara ◽  
Sebastian Rikker ◽  
Martin Wikelski ◽  
Andries Ter Maat ◽  
Henry S. Pollock ◽  
...  

Reduction in metabolic rate and body temperature is a common strategy for small endotherms to save energy. The daily reduction in metabolic rate and heterothermy, or torpor, is particularly pronounced in regions with a large variation in daily ambient temperature. This applies most strongly in temperate bat species (order Chiroptera), but it is less clear how tropical bats save energy if ambient temperatures remain high. However, many subtropical and tropical species use some daily heterothermy on cool days. We recorded the heart rate and the body temperature of free-ranging Pallas' mastiff bats ( Molossus molossus ) in Gamboa, Panamá, and showed that these individuals have low field metabolic rates across a wide range of body temperatures that conform to high ambient temperature. Importantly, low metabolic rates in controlled respirometry trials were best predicted by heart rate, and not body temperature . Molossus molossus enter torpor-like states characterized by low metabolic rate and heart rates at body temperatures of 32°C, and thermoconform across a range of temperatures. Flexible metabolic strategies may be far more common in tropical endotherms than currently known.


1993 ◽  
Vol 71 (9) ◽  
pp. 1787-1792 ◽  
Author(s):  
L. C. Cuyler ◽  
N. A. Øritsland

Lying and standing metabolic rates were determined for two tame Svalbard reindeer while the animals were in their winter lethargic state during January and February. Mean nonfasting metabolic rates for the 59-kg animals were 1.25 W∙kg−1 for lying and 1.64 W∙kg−1 for standing at rest. So the metabolic rate for standing at rest was about 1.3 times the lying resting metabolic rate (RMR). For Svalbard reindeer the lying RMR was 66–78% of the values for other reindeer/caribou, and was 78–89% of the predicted value. The standing RMR was 44–88% of the values from other reindeer/caribou. Total body thermal conductance was 1.95 ± 0.17 W∙°C−1 for lying and 3.08 ± 0.77 W∙°C−1 for standing at rest. The daily energy expenditure during winter was estimated to be about 9654 kJ∙day−1 or 112 W, and was 1.5 times Kleiber's predicted basal metabolic rate. By remaining lying 45% of the time rather than 35% Svalbard reindeer may conserve the equivalent of about 15 days' energy requirement over the winter. With locomotion at 2% of the winter daily activity budget, the Svalbard reindeer conserve about 21 days' energy expenditure, more than that if locomotion were 8.2% of the budget as in caribou (Boertje 1985). Thus, their low energy expenditures for lying and standing and their sedentary activity budget may be considered energy-saving and survival strategies. It is possible that disturbances, which cause the animals to increase activity, may have a detrimental effect on their overall winter energy balance.


2021 ◽  
Author(s):  
Atieh Mirzababaei ◽  
Farideh Shiraseb ◽  
Leila Setayesh ◽  
Atefeh Tavakoli ◽  
Cain C. T. Clark ◽  
...  

Abstract Background: Several epidemiologic studies have reported that dietary acid load is associated with metabolic profiles; however, to our knowledge, the relationship of this dietary pattern with resting metabolic rate (RMR) among obese and overweight females remains unreported. Therefore, this study aimed to evaluate the association of dietary acid load RMR and metabolic components among overweight and obese adult women.Methods: This cross-sectional study was conducted on 375 Iranian adults, aged 18–48 years. Dietary acid load indexes were calculated by using a validated 147-item semi-quantitative FFQ. Biochemical and anthropometric measures were assessed using standard methods. An impedance fat analyzer was used to obtain the body composition and an indirect calorimeter was used to assess the RMR. Result: It was observed that after correction for potential confounders, DBP and NEAP and PRAL scores were inversely associated (P<0.05). NEAP index was inversely associated with RMR (β= -0.25, 95% CI=-0.1.5 to 2.08, P=0.02), and positively associated with WC (β= 1.009, 95% CI=-1.43 to 3.45, P=0.05) and WHR (β= 0.01, 95% CI= -0.01 to0.04, P=0.03), such that subjects with higher scores in NEAP had lower RMR and higher WC and WHR. We also observed that DAL (β= -0.02, 95% CI= -0.08 to0.03, P=0.08) and PRAL (β= -0.037, 95% CI= -1.05 to 0.03 P=0.07) were marginally associated with RMR.Conclusion:The results of the present study suggested that higher dietary acid load scores may be negatively associated with lower RMR, while directly associated with greater WC, WHR, DBP, and HOMA-IR.


2021 ◽  
Author(s):  
Atieh Mirzababaei ◽  
Farideh Shiraseb ◽  
Leila Setayesh ◽  
Atefeh Tavakoli ◽  
Cain C. T. Clark Clark ◽  
...  

Abstract Background: Several epidemiologic studies have reported that dietary acid load is associated with metabolic profiles; however, to our knowledge, the relationship of this dietary pattern with resting metabolic rate (RMR) among obese and overweight females remains unreported. Therefore, this study aimed to evaluate the association of dietary acid load RMR and metabolic components among overweight and obese adult women.Methods: This cross-sectional study was conducted on 375 Iranian adults, aged 18–48 years. Dietary acid load indexes were calculated by using a validated 147-item semi-quantitative FFQ. Biochemical and anthropometric measures were assessed using standard methods. An impedance fat analyzer was used to obtain the body composition and an indirect calorimeter was used to assess the RMR. Result: It was observed that after correction for potential confounders, DBP and NEAP and PRAL scores were inversely associated (P<0.05). NEAP index was inversely associated with RMR (β= -0.25, 95% CI=-0.1.5 to 2.08, P=0.02), and positively associated with WC (β= 1.009, 95% CI=-1.43 to 3.45, P=0.05) and WHR (β= 0.01, 95% CI= -0.01 to0.04, P=0.03), such that subjects with higher scores in NEAP had lower RMR and higher WC and WHR. We also observed that DAL (β= -0.02, 95% CI= -0.08 to0.03, P=0.08) and PRAL (β= -0.037, 95% CI= -1.05 to 0.03 P=0.07) were marginally associated with RMR.Conclusion:The results of the present study suggested that higher dietary acid load scores may be negatively associated with lower RMR, while directly associated with greater WC, WHR, DBP, and HOMA-IR.


1997 ◽  
Vol 75 (11) ◽  
pp. 1781-1789 ◽  
Author(s):  
Patrice Boily ◽  
David M. Lavigne

Resting metabolic rate (RMR) data obtained from five juvenile and three adult female grey seals (Halichoerus grypus) in captivity over a period of 3.5 years were examined for developmental and seasonal changes. Three juveniles exhibited a significant relationship between log10 RMR and log10 mass, with individual slopes ranging from 0.42 to 1.62. Two of these exhibited a significant relationship between log10 RMR and log10 age. The remaining two juveniles and the three adults exhibited no significant relationship between RMR and body mass. With increasing size and age, RMRs of juveniles approached predicted values for adult mammals, but the large variation made it difficult to establish the precise age at which they achieved an adult-like RMR. RMRs of adults and juveniles exhibited marked seasonal changes. In juveniles, seasonal changes in RMR were limited to the annual moult, when the average RMR was 35% higher than during the rest of the year. In adults, changes in RMR were not limited to the time of the annual moult; rather, RMR was lower (by up to 50%) in the summer than during other seasons.


1959 ◽  
Vol 37 (3) ◽  
pp. 473-478 ◽  
Author(s):  
O. Héroux ◽  
F. Depocas ◽  
J. S. Hart

Physiological adjustments to cold temperature have been compared in white rats exposed either to the outdoor fluctuating environmental conditions or to the indoor constant temperature conditions. While the metabolic adjustments such as increased peak metabolism and decreased shivering were similar in outdoor and indoor rats exposed to cold, the adjustments in insulation and thermoneutral metabolic rates were quite different. The pelage insulation increased in the rats kept outside during the winter but remained unchanged in the rats kept in a constant temperature room maintained at 6 °C. The resting metabolic rate measured at 30 °C increased in the 6 °C acclimated rats but not in the winter-exposed animals. Over the temperature range +30 °C to −15 °C, while the indoor cold-acclimated rats had a higher metabolic rate than their controls acclimated to 30 °C, the winter rats had a lower metabolism than their summer controls.


2000 ◽  
Vol 203 (6) ◽  
pp. 1003-1016 ◽  
Author(s):  
M.J. Donohue ◽  
D.P. Costa ◽  
M.E. Goebel ◽  
J.D. Baker

Young pinnipeds, born on land, must eventually enter the water to feed independently. The aim of this study was to examine developmental factors that might influence this transition. The ontogeny of metabolic rate and thermoregulation in northern fur seal, Callorhinus ursinus, pups was investigated at two developmental stages in air and water using open-circuit respirometry. Mean in-air resting metabolic rate (RMR) increased significantly from 113+/−5 ml O(2)min(−)(1) (N=18) pre-molt to 160+/−4 ml O(2)min(−)(1) (N=16; means +/− s.e.m.) post-molt. In-water, whole-body metabolic rates did not differ pre- and post-molt and were 2.6 and 1.6 times in-air RMRs respectively. Mass-specific metabolic rates of pre-molt pups in water were 2.8 times in-air rates. Mean mass-specific metabolic rates of post-molt pups at 20 degrees C in water and air did not differ (16.1+/−1.7 ml O(2)min(−)(1)kg(−)(1); N=10). In-air mass-specific metabolic rates of post-molt pups were significantly lower than in-water rates at 5 degrees C (18.2+/−1.1 ml O(2)min(−)(1)kg(−)(1); N=10) and 10 degrees C (19.4+/−1.7 ml O(2)min(−)(1)kg(−)(1); N=10; means +/− s.e.m.). Northern fur seal pups have metabolic rates comparable with those of terrestrial mammalian young of similar body size. Thermal conductance was independent of air temperature, but increased with water temperature. In-water thermal conductance of pre-molt pups was approximately twice that of post-molt pups. In-water pre-molt pups matched the energy expenditure of larger post-molt pups while still failing to maintain body temperature. Pre-molt pups experience greater relative costs when entering the water regardless of temperature than do larger post-molt pups. This study demonstrates that the development of thermoregulatory capabilities plays a significant role in determining when northern fur seal pups enter the water.


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