Is repeatability of metabolic rate influenced by social separation? A test with a teleost fish

Metabolic rates are typically thought to have important influences on fitness and more broadly be relevant to the ecology and evolution of animals. Previous studies demonstrate that metabolic rates are repeatable to a certain extent under constant conditions, but how social conditions influence the repeatability of metabolic rate remains largely unknown. In this study, we investigated the repeatability of resting metabolic rate (RMR) in the highly social crucian carp ( Carassius auratus ) after being socially separated for different time periods relative to control fish that were not socially separated. We found that RMR was repeatable in fish in the control group, while the repeatability of RMR disappeared quickly (even within 7 days) when fish were exposed to social separation. This study is the first to our knowledge to examine the role of social separation for different time periods on the repeatability of intra-individual physiological variation in fish. We highlight that the inter-individual repeatability of metabolic rate can be substantial over time but was eliminated by social separation. The findings indicate that the repeatability of metabolic rate in fish is condition dependent, and that the change in repeatability of metabolic rate should not be overlooked when considering the ecological and evolutionary effects of environmental change.

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Effects of ultraviolet radiation on metabolic rate and fitness of Aedes albopictus and Culex pipiens mosquitoes

10.7287/peerj.preprints.26722 ◽

2018 ◽

Author(s):

Oswaldo C Villena ◽

Bahram Momen ◽

Joseph Sullivan ◽

Paul T Leisnham

Keyword(s):

Metabolic Rate ◽

Microbial Communities ◽

Aedes Albopictus ◽

Culex Pipiens ◽

Environmental Changes ◽

Negative Impact ◽

Transmission Rate ◽

Major Effect ◽

Control Group ◽

Metabolic Rates

Environmental changes will alter many environmental factors in the coming years including temperature, precipitation, humidity, and the amount of solar radiation reaching the earth’s surface, which in turn will have an impact on living organisms like invertebrates. In this study, we assessed the effect of UV-B radiation upon the metabolic rate and upon three fitness parameters (survival, development time, and body size) of the mosquitoes Aedes albopictus and Culex pipiens, and upon the production of microbial resources on which mosquito larvae feed in aquatic microcosms. We set up three UV-B radiation treatments mimicking levels typically measured in full-sun (FS) and shade (S) conditions, as well as a control group with no UV-B radiation (NUV). The metabolic rate expressed as heat production (µwatts/ml) for larvae and microbial community was measured at days 1, 8, and 15. Our results indicated that UV-B radiation affected the metabolic rate of both Cx. pipiens and Ae. albopictus larvae; metabolic rates were significantly higher in full-sun (FS) compared to shade (S) and no-UV condition (NUV), at days 8 and 15 compared to day 1 (Figures 1A and 1B). Culex pipiens metabolic rates were significantly higher than Ae. albopictus at day 15 compared to days 1 and 8 (Figure 1B). Metabolic rates were significantly lower in microbial communities from vials with Ae. albopictus larvae, Cx. pipiens larvae, and no larvae in FS conditions compared to vials from S and NUV conditions, especially at day 8 (Figure 2A and 2B). There was a major effect of UV-B conditions only on the survival of Ae. albopictus and Cx. pipiens mosquitoes, with significantly lower survival in FS compared to S and NUV conditions. UV-B radiation at levels found in aquatic environments in open fields showed a negative impact on the metabolic rate of Ae. albopictus and Cx. pipiens larvae and on the microbial communities on which they feed. These negative impacts could have important implications for the distribution and abundance of these mosquitoes and for the transmission rate of illness caused by the pathogens that these two broadly distributed mosquitoes transmit.

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Resting and field metabolic rates of Awassi sheep and Baladi goats raised by Negev bedouin

The Journal of Agricultural Science ◽

10.1017/s0021859620000726 ◽

2020 ◽

Vol 158 (5) ◽

pp. 431-437

Author(s):

Michael Kam ◽

Shaher El-Meccawi ◽

Arieh Brosh ◽

A. Allan Degen

Keyword(s):

Metabolic Rate ◽

Resting Metabolic Rate ◽

Arid Areas ◽

Metabolic Rates ◽

Herbaceous Vegetation ◽

Sheep And Goats ◽

Awassi Sheep ◽

Natural Pasture ◽

Field Metabolic Rates ◽

The Cost

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.

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SUMMIT METABOLISM OF NEWBORN CALVES WITH AND WITHOUT COLOSTRUM FEEDING

Canadian Journal of Animal Science ◽

10.4141/cjas86-103 ◽

1986 ◽

Vol 66 (4) ◽

pp. 937-944 ◽

Cited By ~ 15

Author(s):

M. OKAMOTO ◽

J. B. ROBINSON ◽

R. J. CHRISTOPHERSON ◽

B. A. YOUNG

Keyword(s):

Body Weight ◽

Metabolic Rate ◽

Rectal Temperature ◽

Cold Water ◽

Water Immersion ◽

Resting Metabolic Rate ◽

The Body ◽

Metabolic Rates ◽

Colostrum Feeding ◽

Time Required

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

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Metabolic strategies for winter survival by Svalbard reindeer

Canadian Journal of Zoology ◽

10.1139/z93-254 ◽

1993 ◽

Vol 71 (9) ◽

pp. 1787-1792 ◽

Cited By ~ 12

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.

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Role of insulin in thermogenic responses to refeeding in 3-day-fasted rats

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1983.245.2.e160 ◽

1983 ◽

Vol 245 (2) ◽

pp. E160-E165 ◽

Cited By ~ 1

Author(s):

N. J. Rothwell ◽

M. E. Saville ◽

M. J. Stock

Keyword(s):

Metabolic Rate ◽

Resting Metabolic Rate ◽

Insulin Injection ◽

Zucker Rats ◽

Corn Flour ◽

Plasma Insulin Levels ◽

Obese Zucker Rats ◽

Fasted Rats ◽

Thermogenic Response

Refeeding 3-day-fasted rats with 40 kJ carbohydrate (CHO; corn flour) or protein (gelatin) caused a rise in plasma insulin levels 3 h later, but refeeding fat or injection of norepinephrine (400 micrograms/kg) had no effect. Injection of insulin (0.25 U) caused a 15% rise in metabolic rate 24 h later in fasted rats that could be inhibited by treatment with propranolol. Refeeding rats with a single CHO meal produced an increase in oxygen consumption (15%) 24 h later that was inhibited by injection of diazoxide or 2-deoxy-D-glucose given at the time of the meal. The thermogenic response to insulin injection was unaffected by treatment with diazoxide or 2-deoxy-D-glucose. Genetically obese Zucker rats failed to increase metabolic rate after insulin or CHO. In normally fed lean rats, maintained on a stock diet or a palatable cafeteria diet, insulin (4 U) enhanced the thermogenic response to norepinephrine and stimulated resting metabolic rate (16%) in the cafeteria-fed rats. These data suggest that insulin is involved in the thermogenic responses to food and catecholamines.

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Developmental and seasonal changes in resting metabolic rates of captive female grey seals

Canadian Journal of Zoology ◽

10.1139/z97-807 ◽

1997 ◽

Vol 75 (11) ◽

pp. 1781-1789 ◽

Cited By ~ 21

Author(s):

Patrice Boily ◽

David M. Lavigne

Keyword(s):

Metabolic Rate ◽

Body Mass ◽

Adult Female ◽

Significant Relationship ◽

Seasonal Changes ◽

Resting Metabolic Rate ◽

Halichoerus Grypus ◽

Metabolic Rates ◽

In Captivity ◽

Predicted Values

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.

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COMPARISON BETWEEN SEASONAL AND THERMAL ACCLIMATION IN WHITE RATS: I. METABOLIC AND INSULATIVE CHANGES

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o59-048 ◽

1959 ◽

Vol 37 (3) ◽

pp. 473-478 ◽

Cited By ~ 21

Author(s):

O. Héroux ◽

F. Depocas ◽

J. S. Hart

Keyword(s):

Metabolic Rate ◽

Constant Temperature ◽

Environmental Conditions ◽

Resting Metabolic Rate ◽

Thermal Acclimation ◽

Cold Temperature ◽

Metabolic Rates ◽

Temperature Range ◽

White Rats ◽

Physiological Adjustments

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.

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

Journal of Experimental Biology ◽

10.1242/jeb.203.6.1003 ◽

2000 ◽

Vol 203 (6) ◽

pp. 1003-1016 ◽

Cited By ~ 6

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.

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Physiological Effects of Weight Cycling in Female Lightweight Rowers

Canadian Journal of Applied Physiology ◽

10.1139/h93-025 ◽

1993 ◽

Vol 18 (3) ◽

pp. 291-303 ◽

Cited By ~ 11

Author(s):

Linda J. McCargar ◽

Deanna Simmons ◽

Neil Craton ◽

Jack E. Taunton ◽

C. Laird Birmingham

Keyword(s):

Body Weight ◽

Metabolic Rate ◽

Resting Metabolic Rate ◽

Metabolic Changes ◽

Fat Free Mass ◽

Control Group ◽

Weight Cycling ◽

Weight Fluctuation ◽

Healthy Female ◽

History Of

Repeated cycles of weight loss and regain are referred to as weight cycling. It is a practice of many athletes who must achieve a low body weight. The purpose of this study was to determine whether a history of weight cycling results in sustained metabolic changes. Healthy female rowers with a history of dieting and weight fluctuation (n = 7) were compared to a control group of rowers who had never dieted (n = 7). Anthropometric and metabolic measurements were done at pre-, peak, and off-season during a 1-year period. At peak season the weight cyclers restricted their food intake and lost 4.2 ± 1.8 kg, and subsequently regained 4.0 ± 2.1 kg in the off-season. This was different from the controls (p =.003), who maintained a stable body weight at all times. No other group differences were observed. Resting metabolic rate (RMR) and triiodothyronine (T3) changed with time (p =.001, p =.000, respectively) in both groups, which appeared to reflect changes in fat free mass (FFM), not body weight. Long-term metabolic changes were not observed in these athletes. Key words: weight cycling, metabolic rate, body composition, rowers

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