scholarly journals Energetics of locomotion by the Australian water rat (Hydromys chrysogaster): a comparison of swimming and running in a semi-aquatic mammal

1999 ◽  
Vol 202 (4) ◽  
pp. 353-363 ◽  
Author(s):  
F.E. Fish ◽  
R.V. Baudinette
Keyword(s):  
Metabolic Rate ◽  
Bound Water ◽  
Minimum Cost ◽  
Wave Drag ◽  
Swimming Velocity ◽  
Cost Of Transport ◽  
Australian Water ◽  
Aquatic Mammal ◽  
Hydromys Chrysogaster ◽  
Aquatic Mammals

Semi-aquatic mammals occupy a precarious evolutionary position, having to function in both aquatic and terrestrial environments without specializing in locomotor performance in either environment. To examine possible energetic constraints on semi-aquatic mammals, we compared rates of oxygen consumption for the Australian water rat (Hydromys chrysogaster) using different locomotor behaviors: swimming and running. Aquatic locomotion was investigated as animals swam in a water flume at several speeds, whereas water rats were run on a treadmill to measure metabolic effort during terrestrial locomotion. Water rats swam at the surface using alternate pelvic paddling and locomoted on the treadmill using gaits that included walk, trot and half-bound. Water rats were able to run at twice their maximum swimming velocity. Swimming metabolic rate increased with velocity in a pattern similar to the ‘humps’ and ‘hollows’ for wave drag experienced by bodies moving at the water surface. Metabolic rate increased linearly during running. Over equivalent velocities, the metabolic rate for running was 13–40 % greater than for swimming. The minimum cost of transport for swimming (2.61 J N-1 m-1) was equivalent to values for other semi-aquatic mammals. The lowest cost for running (2.08 J N-1 m-1) was 20 % lower than for swimming. When compared with specialists at the extremes of the terrestrial-aquatic continuum, the energetic costs of locomoting either in water or on land were high for the semi-aquatic Hydromys chrysogaster. However, the relative costs for H. chrysogaster were lower than when an aquatic specialist attempts to move on land or a terrestrial specialist attempts to swim.

Energetics of swimming by the platypus Ornithorhynchus anatinus: metabolic effort associated with rowing.

1997 ◽  
Vol 200 (20) ◽  
pp. 2647-2652 ◽  
Author(s):  
F E Fish ◽  
R V Baudinette ◽  
P B Frappell ◽  
M P Sarre
Keyword(s):  
Metabolic Rate ◽  
Water Current ◽  
Transport Costs ◽  
Cost Of Transport ◽  
Aquatic Locomotion ◽  
Ornithorhynchus Anatinus ◽  
Thrust Generation ◽  
The Cost ◽  
High Thrust ◽  
Aquatic Mammals

The metabolism of swimming in the platypus Ornithorhynchus anatinus Shaw was studied by measurement of oxygen consumption in a recirculating water flume. Platypuses swam against a constant water current of 0.45-1.0 ms-1. Animals used a rowing stroke and alternated bouts of surface and submerged swimming. Metabolic rate remained constant over the range of swimming speeds tested. The cost of transport decreased with increasing velocity to a minimum of 0.51 at 1.0 ms-1. Metabolic rate and cost of transport for the platypus were lower than values for semiaquatic mammals that swim at the water surface using a paddling mode. However, relative to transport costs for fish, the platypus utilized energy at a similar level to highly derived aquatic mammals that use submerged swimming modes. The efficient aquatic locomotion of the platypus results from its specialised rowing mode in conjunction with enlarged and flexible forefeet for high thrust generation and a behavioral strategy that reduces drag and energy cost by submerged swimming.

Swimming velocities, breathing patterns, and estimated costs of locomotion in migrating gray whales, Eschrichtius robustus

1983 ◽  
Vol 61 (3) ◽  
pp. 647-652 ◽  
Author(s):  
James L. Sumich
Keyword(s):  
Minimum Cost ◽  
San Diego County ◽  
Swimming Velocity ◽  
Eschrichtius Robustus ◽  
Breathing Patterns ◽  
Method Of Least Squares ◽  
Cost Of Transport ◽  
Total Drag ◽  
Gray Whales ◽  
Energy Expenditures

This study was conducted to determine the swimming velocities and breathing patterns of south-migrating gray whales (Eschrichtius robustus) and to estimate their minimum costs of transport during migration. Swimming velocities and breathing patterns were monitored with theodolite techniques from a coastal vantage point on Point Loma, San Diego County, CA. Estimates of energy expenditures were based on observed breathing rates and on extrapolations of tidal lung volume and oxygen uptake measurements made on unrestrained and on captive gray whales. The results of 74 whales monitored over 354 whale∙km yielded mean velocities of 2.0 m∙s−1 and mean breathing rates of 0.72 breaths∙min−1. The regression of breathing rates on swimming velocities (V) by the method of least squares is best described by the equation, breathing rate = 0.5 + 0.024 V3.0. The calculated minimum cost of transport for a 12-m, 15-t whale was 0.046 W∙s∙N−1∙m−1 at the observed mean swimming velocity of 2 m∙s−1 during the southward migration. The coefficient of total drag was estimated to be 0.06. Rates of lipid depletion approximate 6% of body weight per month if no supplementary food intake occurs for the 4- to 6-month period each year that gray whales are presumed to fast.

Energetics of surface swimming in Brandt's cormorants (Phalacrocorax penicillatus brandt)

2000 ◽  
Vol 203 (24) ◽  
pp. 3727-3731 ◽  
Author(s):  
A. Ancel ◽  
L.N. Starke ◽  
P.J. Ponganis ◽  
R. Van Dam ◽  
G.L. Kooyman
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Energy Requirements ◽  
Swimming Velocity ◽  
Specific Rate ◽  
Cost Of Transport ◽  
Metabolic Chamber ◽  
Rate Of Oxygen Consumption ◽  
The Cost

The energy requirements of Brandt's cormorants (Phalacrocorax penicillatus) during surface swimming were measured in birds swimming under a metabolic chamber in a water flume. From the oxygen consumption recordings, we extrapolated the metabolic rate and cost of transport at water speeds ranging from 0 to 1.3 m s(−)(1). In still water, the birds' mean mass-specific rate of oxygen consumption (V(O2)) while floating at the surface was 20.2 ml O(2)min(−)(1)kg(−)(1), 2.1 times the predicted resting metabolic rate. During steady-state voluntary swimming against a flow, their V(O2) increased with water speed, reaching 74 ml O(2)min(−)(1)kg(−)(1) at 1.3 m s(−)(1), which corresponded to an increase in metabolic rate from 11 to 25 W kg(−)(1). The cost of transport decreased with swimming velocity, approaching a minimum of 19 J kg(−)(1)m(−)(1) for a swimming speed of 1.3 m s(−)(1). Surface swimming in the cormorant costs approximately 18 % less than sub-surface swimming. This confirms similar findings in tufted ducks (Aythya fuligula) and supports the hypothesis that increased energy requirements are necessary in these birds during diving to overcome buoyancy and heat loss during submergence.

Functional classification of harbor seal (Phoca vitulina) dives using depth profiles, swimming velocity, and an index of foraging success

1999 ◽  
Vol 77 (1) ◽  
pp. 74-87 ◽  
Author(s):  
Véronique Lesage ◽  
Mike O Hammill ◽  
Kit M Kovacs
Keyword(s):  
Minimum Cost ◽  
Harbor Seal ◽  
Phoca Vitulina ◽  
Swimming Velocity ◽  
Harbor Seals ◽  
Cost Of Transport ◽  
Lawrence Estuary ◽  
Stomach Temperature ◽  
St Lawrence Estuary

Time-depth-speed recorders and stomach-temperature sensors were deployed on 11 harbor seals (Phoca vitulina) in the St. Lawrence estuary to examine their diving and foraging behavior. Fifty-four percent of dives were to depths of <4 m. Dives that were [Formula: see text] 4 m deep were classified into five distinct types, using a combination of principal components analysis and hierarchical and nonhierarchical clustering analyses. Feeding, indicated by a sharp decline in stomach temperature, occurred during dives of all five types, four of which were U-shaped, while one was V-shaped. Seals swam at speeds near the minimum cost of transport (MCT) during descents and ascents. V-shaped dives had mean depths of 5.8 m, lasted an average of 40 s, and often preceded or followed periods of shallow-water (<4 m) activity. Seals invariably dove to the bottom when performing U-shaped dives. These dives were to an average depth of 20 m during daylight and occurred in shallower waters (~8 m) at twilight and during the night. Once on the bottom, seals (i) swam at MCT speeds with occasional bursts of speed, (ii) swam at speeds near MCT but not exceeding it, or (iii) remained stationary or swam slowly at about 0.15 m/s, occasionally swimming faster. It is unlikely that all dives to depths [Formula: see text] 4 m are dedicated to foraging. However, the temporal segregation of dive types suggests that all types are used during foraging, although they may represent different strategies.

Interactive effects of salinity on metabolic rate, activity, growth and osmoregulation in the euryhaline milkfish (Chanos chanos)

1998 ◽  
Vol 201 (24) ◽  
pp. 3355-3366
Author(s):  
C Swanson
Keyword(s):  
Metabolic Rate ◽  
High Salinity ◽  
Swimming Performance ◽  
Interactive Effects ◽  
Routine Activity ◽  
Swimming Velocity ◽  
Activity Levels ◽  
Salinity Adaptation ◽  
Chanos Chanos ◽  
Wide Range

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.

Hydrodynamic drag in steller sea lions (Eumetopias jubatus)

2000 ◽  
Vol 203 (12) ◽  
pp. 1915-1923 ◽  
Author(s):  
L.L. Stelle ◽  
R.W. Blake ◽  
A.W. Trites
Keyword(s):  
Minimum Cost ◽  
The Body ◽  
Hydrodynamic Drag ◽  
Eumetopias Jubatus ◽  
Steller Sea Lions ◽  
California Sea Lions ◽  
Cost Of Transport ◽  
Sea Lions ◽  
Drag Forces ◽  
The Individual

Drag forces acting on Steller sea lions (Eumetopias jubatus) were investigated from ‘deceleration during glide’ measurements. A total of 66 glides from six juvenile sea lions yielded a mean drag coefficient (referenced to total wetted surface area) of 0.0056 at a mean Reynolds number of 5.5×10(6). The drag values indicate that the boundary layer is largely turbulent for Steller sea lions swimming at these Reynolds numbers, which are past the point of expected transition from laminar to turbulent flow. The position of maximum thickness (at 34 % of the body length measured from the tip of the nose) was more anterior than for a ‘laminar’ profile, supporting the idea that there is little laminar flow. The Steller sea lions in our study were characterized by a mean fineness ratio of 5.55. Their streamlined shape helps to delay flow separation, reducing total drag. In addition, turbulent boundary layers are more stable than laminar ones. Thus, separation should occur further back on the animal. Steller sea lions are the largest of the otariids and swam faster than the smaller California sea lions (Zalophus californianus). The mean glide velocity of the individual Steller sea lions ranged from 2.9 to 3.4 m s(−)(1) or 1.2-1.5 body lengths s(−)(1). These length-specific speeds are close to the optimum swim velocity of 1.4 body lengths s(−)(1) based on the minimum cost of transport for California sea lions.

scholarly journals Does Metabolic Rate Increase Linearly with Running Speed in all Distance Runners?

2017 ◽  
Vol 02 (01) ◽  
pp. E1-E8 ◽  
Author(s):  
Matthew Batliner ◽  
Shalaya Kipp ◽  
Alena Grabowski ◽  
Rodger Kram ◽  
William Byrnes
Keyword(s):  
Oxygen Uptake ◽  
Metabolic Rate ◽  
Perceived Exertion ◽  
Running Economy ◽  
Rating Of Perceived Exertion ◽  
Distance Runners ◽  
Cost Of Transport ◽  
Linear Relationships ◽  
Distance Running Performance ◽  
Elite Runners

AbstractRunning economy (oxygen uptake or metabolic rate for running at a submaximal speed) is one of the key determinants of distance running performance. Previous studies reported linear relationships between oxygen uptake or metabolic rate and speed, and an invariant cost of transport across speed. We quantified oxygen uptake, metabolic rate, and cost of transport in 10 average and 10 sub-elite runners. We increased treadmill speed by 0.45 m·s−1 from 1.78 m·s−1 (day 1) and 2.01 m·s−1 (day 2) during each subsequent 4-min stage until reaching a speed that elicited a rating of perceived exertion of 15. Average runners’ oxygen uptake and metabolic rate vs. speed relationships were best described by linear fits. In contrast, the sub-elite runners’ relationships were best described by increasing curvilinear fits. For the sub-elites, oxygen cost of transport and energy cost of transport increased by 12.8% and 9.6%, respectively, from 3.58 to 5.14 m·s−1. Our results indicate that it is not possible to accurately predict metabolic rates at race pace for sub-elite competitive runners from data collected at moderate submaximal running speeds (2.68–3.58 m·s−1). To do so, metabolic rate should be measured at speeds that approach competitive race pace and curvilinear fits should be used for extrapolation to race pace.

The life-cycle of Echinoparyphium hydromyos sp.nov. (Digenea: Echinostomatidae) from the Australian water-rat

Parasitology ◽  
1967 ◽  
Vol 57 (1) ◽  
pp. 19-30 ◽  
Author(s):  
L. Madeline Angel
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Experimental Work ◽  
Field Work ◽  
Type Material ◽  
South Australian Museum ◽  
The South ◽  
Australian Water ◽  
Australian Museum ◽  
Hydromys Chrysogaster

Echinoparyphium hydromyos sp.nov. with forty-five collar spines is described from the Australian water rat, Hydromys chrysogaster Geoffr.The cercaria occurs naturally in Plananisus isingi (Cotton & Godfrey), and all stages in the life-history have been demonstrated experimentally.Encystation occurs in the kidneys of tadpoles.The adult is most closely related to Echinoparyphium recurvatum (Linstow). It differs from this in its greater number of eggs and in its life-history. E. recurvatum occurs predominantly in birds, and is rarely found naturally in mammals. E. hydromyos has been found only in a mammal.Cercaria echinoparyphii hydromyos is compared with C. clelandae Johnston and Angel; it differs from the latter in the ‘compound’ nature of the excretory granules. The adult of C. clelandae has not been demonstrated in spite of a number of experiments to determine it.Type material has been deposited in the South Australian Museum.I wish to acknowledge the help given by my colleague, Patricia M. Thomas, in field work and in other ways, and by Mr Ian Smith, of this department, in the experimental work on life-history studies.

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