The ontogeny of metabolic rate and thermoregulatory capabilities of northern fur seal, Callorhinus ursinus, pups in air and water

2000 ◽  
Vol 203 (6) ◽  
pp. 1003-1016 ◽  
Author(s):  
M.J. Donohue ◽  
D.P. Costa ◽  
M.E. Goebel ◽  
J.D. Baker
Keyword(s):  
Metabolic Rate ◽  
Developmental Stages ◽  
Resting Metabolic Rate ◽  
Thermal Conductance ◽  
Open Circuit ◽  
Whole Body ◽  
Callorhinus Ursinus ◽  
Metabolic Rates ◽  
Northern Fur Seal ◽  
Fur Seal

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.

Metabolic strategies for winter survival by Svalbard reindeer

1993 ◽  
Vol 71 (9) ◽  
pp. 1787-1792 ◽  
Author(s):  
L. C. Cuyler ◽  
N. A. Øritsland
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Energy Requirement ◽  
Resting Metabolic Rate ◽  
Thermal Conductance ◽  
Activity Budget ◽  
Survival Strategies ◽  
Metabolic Rates ◽  
Energy Expenditures ◽  
Svalbard Reindeer

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.

Increased energy expenditure in cystic fibrosis is associated with specific mutations

1992 ◽  
Vol 82 (1) ◽  
pp. 71-76 ◽  
Author(s):  
A. O'Rawe ◽  
I. McIntosh ◽  
J. A. Dodge ◽  
D. J. H. Brock ◽  
A. O. B. Redmond ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pulmonary Function ◽  
Metabolic Rate ◽  
Practical Implication ◽  
Resting Metabolic Rate ◽  
Open Circuit ◽  
Disruptive Effect ◽  
Metabolic Rates ◽  
Control Subjects ◽  
Significant Difference

1. Measurements of resting metabolic rate were made by open-circuit indirect calorimetry in 78 unrelated cystic fibrosis patients and 30 healthy control subjects. The aims of this study were: (i) to determine the range of variability in resting metabolic rate in cystic fibrosis, (ii) to relate this to pulmonary function and body size, and (iii) to investigate the hypothesis that, in cystic fibrosis, genotype exerts a significant influence on energy requirements. 2. There was no significant difference in age or body weight between patients with cystic fibrosis and control subjects. Resting metabolic rates for control subjects fell within ± 10% of predicted values. Fifty-nine per cent of patients with cystic fibrosis had elevated resting metabolic rates (i.e. > 111% of predicted). Genotype analysis divided the patients with cystic fibrosis into three groups: AF508 homozygotes, AF508 heterozygotes and others. Patients homozygous for the AF508 allele had a significantly higher resting metabolic rate (121% of predicted, 95% confidence interval 116-126%), compared with other genotypes (P> 0.005). 3. There were significant differences in pulmonary function between the groups (P> 0.005). However, after adjustment of individual resting metabolic rates for differences in pulmonary function by using analysis of co-variance, resting metabolic rates remained significantly higher for ΔF508 homozygotes than for other genotypes (P<0.05). 4. We conclude that there is a significant contribution to resting metabolic rate in cystic fibrosis associated with specific mutations that is not explained by declining pulmonary function. The increase in resting metabolic rate in patients homozygous for mutations involving a nucleotide-binding fold, which may result from a disruptive effect on ATP binding, indicates a practical implication of genotype identification with the need for effective nutritional intervention and support in this patient subgroup.

Aquatic thermoregulation of captive and free-ranging beavers (Castor canadensis)

1990 ◽  
Vol 68 (11) ◽  
pp. 2409-2416 ◽  
Author(s):  
Robert A. MacArthur ◽  
Alvin P. Dyck
Keyword(s):  
Metabolic Rate ◽  
Cold Water ◽  
Castor Canadensis ◽  
Resting Metabolic Rate ◽  
Whole Body ◽  
Passive Cooling ◽  
Metabolic Rates ◽  
The Mean ◽  
Free Ranging ◽  
Skin Temperatures

Abdominal cooling occurred in 91% of all aquatic excursions documented in free-ranging beavers during fall and winter. Kits aged 4–7 months cooled faster and spent less time foraging in 1–12 °C water than did animals > 1 year old. All beavers tested in the laboratory displayed abdominal cooling in 2–20 °C water, with maximal cooling rates recorded in a 5- to 7-week-old kit. Immersion in cold water induced strong peripheral cooling, though skin temperatures beneath the pelage remained within 4–5 °C of abdominal measurements. The resting metabolic rate of beavers > 1 year old was independent of water temperature between 19 and 31 °C, but increased proportionately at lower temperatures. Whole-body conductance of resting animals was on average 1.6–3.0 times higher in water than in air. Maximum testing metabolic rates in water varied from 1.8 to 2.4 times the mean resting thermoneutral rate in air. Our results suggest that beavers mitigate the thermogenic effort required in water by adopting a thermoregulatory strategy which combines avoidance of prolonged immersion with a tolerance to passive cooling.

Developmental stage does not affect resting metabolic rate in the monitor lizard, Varanus salvator

2019 ◽  
Vol 69 (2) ◽  
pp. 199-212
Author(s):  
Yun-Tao Yao ◽  
Yu Du ◽  
Meng-Chao Fang ◽  
Long-Hui Lin ◽  
Xiang Ji
Keyword(s):  
Metabolic Rate ◽  
Developmental Stage ◽  
Body Mass ◽  
Significant Influence ◽  
Developmental Stages ◽  
Resting Metabolic Rate ◽  
Metabolic Rates ◽  
Mammal Species ◽  
Monitor Lizard ◽  
Varanus Salvator

Abstract We have studied resting metabolic rate (RMR) of the water monitor lizard (Varanus salvator) at different developmental stages (hatchling, juvenile and adult) to test whether individuals at different ages differ in RMR when controlling for the effects of body mass. We found that: 1) resting metabolic rates of hatchlings, juveniles and adults were all positively related to their body mass with the same coefficients and that 2) developmental stage had a non-significant influence on the resting metabolic rate when controlling for the effects of body mass. Our results suggest that variation in resting metabolic rate for V. salvator is directly caused by body mass differences, which conforms to previous findings in mammal species and birds.

Thermoregulation in the only nocturnal simian: the night monkey Aotus trivirgatus

1981 ◽  
Vol 240 (3) ◽  
pp. R156-R165 ◽  
Author(s):  
Y. Le Maho ◽  
M. Goffart ◽  
A. Rochas ◽  
H. Felbabel ◽  
J. Chatonnet
Keyword(s):  
Critical Temperature ◽  
Metabolic Rate ◽  
Response Pattern ◽  
Thermal Environment ◽  
Resting Metabolic Rate ◽  
Thermal Conductance ◽  
Open Circuit ◽  
The Body ◽  
Thermoneutral Zone ◽  
Lower Critical Temperature

The night monkey, a tropical monkey, is the only nocturnal simian; its thermoregulation was studied for comparison with other nocturnal or diurnal primates and other tropical mammals. Resting metabolic rate was 2.6 W (closed-circuit method) and 2.8 W (open-circuit method), 24 and 18% below the value predicted from body mass. The thermoneutral zone was very narrow; the lower critical temperature (LCT) was 28 degrees C and the upper critical temperature (UCT) was 30 degrees C. The body temperature (Tb) was at its minimum (38 degrees C) at an ambient temperature (Ta) of 25 degrees C, thus below the LCT. At low Ta, the increase in metabolic rate (MR) was smaller than predicted by the Scholander model, since MR intersected to a Ta 13 degrees C above Tb when extrapolated to MR = 0; this was attributed to a decrease of body surface area by behavior. The thermal conductance at the LCT was low: 2.3 W . m-2 . degrees C-1. Above the UCT, panting was the major avenue of heat loss. The response pattern of nocturnal habits, low resting metabolic rate, low thermal conductance, and panting in the night monkey, unique among simians, is found in many other mammals of tropical and hot desert habitats; it may be considered as an alternative adaptation to the thermal environment.

scholarly journals Timing of Implantation in the Northern Fur Seal, Callorhinus ursinus

1997 ◽  
Vol 78 (2) ◽  
pp. 675-683 ◽  
Author(s):  
V. B. Scheffer ◽  
A. E. York
Keyword(s):  
Callorhinus Ursinus ◽  
Northern Fur Seal ◽  
Fur Seal

Effect of age on body composition and resting metabolic rate

1990 ◽  
Vol 259 (2) ◽  
pp. E233-E238 ◽  
Author(s):  
N. K. Fukagawa ◽  
L. G. Bandini ◽  
J. B. Young
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Isotope Dilution ◽  
Resting Metabolic Rate ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Open Circuit ◽  
Fat Free Mass ◽  
The Difference ◽  
Old Men

The relationship between fat-free mass (FFM) and resting metabolic rate (RMR) was compared in young men (n = 24; age 18-33 yr), old men (n = 24; 69-89 yr), and old women (n = 20; 67-75 yr). Body composition was assessed using anthropometry, bioelectrical impedance analysis (BIA), and isotope dilution with 18O-labeled water. RMR was measured at least twice using an open-circuit indirect calorimetry system with a ventilated hood. The results indicate that the different methods for assessing body composition vary substantially and should not be used interchangeably. Anthropometry was not adequate to assess group differences in body fatness, although skinfold measures may be appropriate for within-group comparisons. BIA correlated well with the isotope-dilution technique and may be a useful measure of FFM. Finally, RMR was lower in the old men than the young (1.04 +/- 0.02 vs. 1.24 +/- 0.03 kcal/min, P less than 0.001) and remained lower even when adjusted for FFM estimated by isotope dilution (P less than 0.001). RMR in the women was also lower (0.84 +/- 0.02 kcal/min), but in contrast to the difference between young and old men, RMR adjusted for FFM did not differ (P = 0.16) between old men and women. Therefore, it is clear that differences in FFM cannot fully account for the lower RMR in the old, suggesting that aging is associated with an alteration in tissue energy metabolism.

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