Resting Metabolic Rate, Critical Swimming Speed, and Routine Activity of the Euryhaline Cyprinodontid,Aphanius dispar, Acclimated to a Wide Range of Salinities

2000 ◽  
Vol 73 (5) ◽  
pp. 590-596 ◽  
Author(s):  
Itai Plaut
1998 ◽  
Vol 201 (24) ◽  
pp. 3355-3366
Author(s):  
C Swanson

The euryhaline milkfish (Chanos chanos) is an excellent subject for studies of the physiological and behavioral processes involved in salinity adaptation. In this study, energy partitioning for metabolism, activity and growth, maximal activity performance and blood osmotic concentrations were assessed at two activity levels in juvenile milkfish fed equal rations and maintained at a relatively constant temperature (262 C) and at salinities(15, 35 and 55 ?) that represented a wide range of osmoregulatory challenges. Changes in the measured parameters were not consistently related to the magnitude of the trans-integumentary osmotic gradients. Routine oxygen consumption rates were high in 35 ? salinity (mean 1 s.e.m. 1678 mg O2 kg-1 h-1) and comparably low in 15 and 55 ? salinity (1336 and 1273 mg O2 kg-1 h-1, respectively). Routine activity levels (relative swimming velocity) were highest in 35 ? salinity (0. 960.04 L s-1), where L is standard length, intermediate in 15 ? salinity (0.770.03 L s-1) and lowest in 55 ? salinity (0.670.03 L s-1). Growth was significantly higher in 55 ? salinity (3.40.2 % increase in wet body mass per day) than in 35 ?salinity (2.40.2 % increase per day) and intermediate in 15 ? salinity(2.90.5 % increase per day). Maximum swimming velocities decreased with increases in salinity, from 9.90.7 L s-1 in 15 ? salinity to 6.60. 5 L s-1 in 55 ? salinity. Sustained swimming activity above routine levels for 2 h resulted in an increase in blood osmotic concentrations in milkfish in 55 ?salinity, but osmoregulation was re-established during the second 2 h of activity. Thus, patterns of variation in metabolic rate and growth were largely parallel to variations in routine activity although, comparing 15 and 55 ? salinity, elevated maintenance costs for osmoregulation at the high salinity were detectable. Reduced osmoregulatory abilities and reductions in maximal swimming performance suggest that high salinity may constrain activity. The results demonstrate that investigations of salinity adaptation in euryhaline fishes should take into account the interactive effects of salinity on physiology and behavior.


1997 ◽  
Vol 82 (1) ◽  
pp. 156-163 ◽  
Author(s):  
D. A. Smith ◽  
J. Dollman ◽  
R. T. Withers ◽  
M. Brinkman ◽  
J. P. Keeves ◽  
...  

Smith, D. A., J. Dollman, R. T. Withers, M. Brinkman, J. P. Keeves, and D. G. Clark. Relationship between maximum aerobic power and resting metabolic rate in young adult women. J. Appl. Physiol. 82(1): 156–163, 1997.—The literature is inconclusive as to the chronic effect of aerobic exercise on resting metabolic rate (RMR), and furthermore there is a scarcity of data on young women. Thirty-four young women exhibiting a wide range of aerobic fitness [maximum aerobic power (V˙o 2 max) = 32.3–64.8 ml ⋅ kg−1 ⋅ min−1] were accordingly measured for RMR by the Douglas bag method, treadmillV˙o 2 max, and fat-free mass (FFM) by using Siri’s three-compartment model. The interclass correlation ( n = 34) between RMR (kJ/h) and V˙o 2 max(ml ⋅ kg−1 ⋅ min−1) was significant ( r = 0.39, P < 0.05). However, this relationship lost statistical significance when RMR was indexed to FFM and when partial correlation analysis was used to control for FFM differences. Furthermore, multiple linear-regression analysis indicated that only FFM emerged as a significant predictor of RMR (kJ/h). When high- ( n = 12) and low-fitness ( n = 12) groups were extracted from the cohort on the basis ofV˙o 2 max scores, independent t-tests revealed significant between-group differences ( P < 0.05) for RMR (kJ ⋅ kg−1 ⋅ h−1) andV˙o 2 max(ml ⋅ kg−1 ⋅ min−1) but not for RMR (kJ/h), RMR (kJ ⋅ kg FFM−1 ⋅ h−1), and FFM. Analysis of covariance of RMR (kJ/h) with FFM as the covariate also showed no significant difference ( P = 0.56) between high- and low-fitness groups. Thus the results suggest that 1) FFM accounts for most of the differences in RMR between subjects of varyingV˙o 2 max values and 2) the RMR per unit of FFM in young healthy women is unrelated toV˙o 2 max.


1992 ◽  
Vol 70 (2) ◽  
pp. 220-224 ◽  
Author(s):  
Nina Hedlund Markussen ◽  
Morten Ryg ◽  
Nils Are Øritsland

The metabolic rate of normally fed harbour seals (Phoca vitulina) was measured during starvation and the subsequent refeeding period. Resting metabolic rate was calculated from the y-intercept of the metabolic rate versus swimming speed curves and was 20% lower during the starvation period than during normal feeding. During starvation, about 50% of mass loss was fat, i.e., 77% of the energy was obtained from fat. Metabolic rate returned to the initial value about 1 week after the onset of refeeding.


1980 ◽  
Vol 85 (1) ◽  
pp. 295-309
Author(s):  
I. G. PRIEDE ◽  
F.G. T. HOLLIDAY

1. Plaice and other flatfish can be induced to swim down a slope of about 60° against an upwelling water flow in a water tunnel. 2. A tilting Brett-type tunnel respirometer based on the above principle enabled laboratory experiments on swimming plaice to be carried out. 3. From trials at 5°, 10°, 15 °C, the relationship between specific swimming speed, V (body lengths s−1), oxygen consumption, R (mg−1. kg−1 h−1) and temperature, T is: log10 = 0.3318V + log10 (2.45T+26.52). 4. If the fish is resting (i.e. V = 0), the oxygen consumption is lower than predicted by the above equation. At rest: R = 3.14T+2.66. 5. The cost of swimming in plaice is very similar to that of typical round fish such as haddock but the resting metabolic rate is lower than for haddock. 6. Before swimming, a negatively buoyant fish such as plaice must lift off the bottom. This cost of lift-off or posture effect makes it uneconomical for plaice to swim at speeds below 0.6V.


Author(s):  
Habib Yarizadeh ◽  
Leila Setayesh ◽  
Caroline Roberts ◽  
Mir Saeed Yekaninejad ◽  
Khadijeh Mirzaei

Abstract. Objectives: Obesity plays an important role in the development of chronic diseases including cardiovascular disease and diabetes. A low resting metabolic rate (RMR) for a given body size and composition is a risk factor for obesity, however, there is limited evidence available regarding the association of nutrient patterns and RMR. The aim of this study was to determine the association of nutrient patterns and RMR in overweight and obese women. Study design: This cross-sectional study was conducted on 360 women who were overweight or obese. Method: Dietary intake was assessed using a semi-quantitative standard food frequency questionnaire (FFQ). Nutrient patterns were also extracted by principal components analysis (PCA). All participants were evaluated for their body composition, RMR, and blood parameters. Result: Three nutrient patterns explaining 64% of the variance in dietary nutrients consumption were identified as B-complex-mineral, antioxidant, and unsaturated fatty acid and vitamin E (USFA-vit E) respectively. Participants were categorized into two groups based on the nutrient patterns. High scores of USFA-vit E pattern was significantly associated with the increase of RMR (β = 0.13, 95% CI = 0.79 to 68.16, p = 0.04). No significant associations were found among B-complex-mineral pattern (β = −0.00, 95% CI = −49.67 to 46.03, p = 0.94) and antioxidant pattern (β = 0.03, 95% CI −41.42 to 22.59, p = 0.56) with RMR. Conclusion: Our results suggested that the “USFA-vit E” pattern (such as PUFA, oleic, linoleic, vit.E, α-tocopherol and EPA) was associated with increased RMR.


Author(s):  
Pathima Fairoosa ◽  
Indu Waidyatilaka ◽  
Maduka de Lanerolle-Dias ◽  
Pujitha Wickramasinghe ◽  
Pulani Lanerolle

Author(s):  
Andrew Clarke

The model of West, Brown & Enquist (WBE) is built on the assumption that the metabolic rate of cells is determined by the architecture of the vascular network that supplies them with oxygen and nutrients. For a fractal-like network, and assuming that evolution has minimised cardiovascular costs, the WBE model predicts that s=metabolism should scale with mass with an exponent, b, of 0.75 at infinite size, and ~ 0.8 at realistic larger sizes. Scaling exponents ~ 0.75 for standard or resting metabolic rate are observed widely, but far from universally, including in some invertebrates with cardiovascular systems very different from that assumed in the WBE model. Data for field metabolic rate in vertebrates typically exhibit b ~ 0.8, which matches the WBE prediction. Addition of a simple Boltzmann factor to capture the effects of body temperature on metabolic rate yields the central equation of the Metabolic Theory of Ecology (MTE). The MTE has become an important strand in ecology, and the WBE model is the most widely accepted physical explanation for the scaling of metabolic rate with body mass. Capturing the effect of temperature through a Boltzmann factor is a useful statistical description but too simple to qualify as a complete physical theory of thermal ecology.


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