Water, Sodium and Energy Turnover in Free-Living Little Penguins, Eudyptula-Minor

1988 ◽  
Vol 36 (4) ◽  
pp. 429 ◽  
Author(s):  
B Green ◽  
N Brothers ◽  
R Gales
Keyword(s):  
Sea Water ◽  
Activity Patterns ◽  
Metabolic Rates ◽  
Total Water ◽  
Free Living ◽  
Sodium Influx ◽  
Water Ingestion ◽  
Water Influx ◽  
The Mean ◽  
Total Sodium

Water influx rates of adult little penguins ranged from 20 ml kg-' day-' in fasting (incubating and moulting) birds to about 650 ml kg-' day- ' in birds that were foraging at sea over extended periods. The sodium influx rates of adults ranged from almost zero up to 87 mmol kg-' day-', depending on the activity patterns of the birds, and were closely correlated with water influxes. The metabolic rates of adult penguins were 1.7 and 2.8 times standard metabolic rates during fasting and foraging respectively, and were also closely correlated with water influx rates. The mean food consumption rate for the maintenance of chicks was about 236 g kg-' day-', equivalent to a maintenance energy intake of 1460 kJ kg-' day-'. Partitioning calculations show that sea water ingestion during foraging represented about 10% of total water influx, but about 40% of total sodium influx. Nasal salt secretions were hyperosmotic to serum and it was calculated that daily sodium influxes could be totally eliminated via this route within 4 hours.

Field Metabolic Rates, Water Fluxes, and Feeding Rates of Quokkas, Setonix-Brachyurus, and Tammars, Macropus-Eugenii, in Western-Australia

1989 ◽  
Vol 37 (5) ◽  
pp. 553 ◽  
Author(s):  
KA Nagy ◽  
AJ Bradley ◽  
KD Morris
Keyword(s):  
Water Intake ◽  
Dry Matter ◽  
Feeding Rate ◽  
Metabolic Rates ◽  
Feeding Rates ◽  
Total Water ◽  
Water Influx ◽  
Field Metabolic Rates ◽  
Free Ranging ◽  
Total Water Intake

Field metabolic rates (FMRS) and water influx rates were measured by means of doubly labelled water in free-ranging quokkas living on Rottnest I, and free-ranging tammar wallabies living on Garden I. Feeding rates were estimated from energy requirements. Quokkas ranging in body mass from 1.44 to 2.83 kg (mean 1.90 kg) had FMRS averaging 0.574 mL C02 (g.h)-', which is equivalent to 548 kJ d-'. Their rates of total water intake averaged 47.3 mL (kg.d)-', or 90.5 mL d-'. Estimated feeding rate was 54.8 g (dry matter) per day, and water ingested as part of the food (preformed and metabolically produced) can completely account for total water intake. We believe that quokkas did not drink water during our field measurements. Tammars ranging in body mass from 3.20 to 6.35 kg (mean 4.38 kg) had FMRS averaging 0.518 mL CO2 (g.h)-', which is equivalent to 1150 kJ d-'. Their rates of water influx averaged 57.5 mL (kg.d)-', or 270 mL d-', and their estimated feeding rate was 115 g (dry matter) per day. Tammars also probably did not drink free-standing water during our study. FMRs of quokkas averaged 1 .80 x basal metabolic rate (BMR), and FMRS of tammars averaged 1.87 x BMR; this difference is not significant. We estimate that the 5000 quokkas on Rottnest I. consume at least 100 000 kg of plant matter (dry mass) per year, and the 2173 tammars on Garden I. ingest more than 90 000 kg. Measurements of food availability are needed to permit evaluation of the relationship between food supply and demand for these two populations of macropod marsupials.

Sea Water Drinking and Water Flux in Starved and in Fed Harbor Seals, Phoca vitulina

1971 ◽  
Vol 49 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Florent Depocas ◽  
J. Sanford Hart ◽  
H. Dean Fisher
Keyword(s):  
Food Intake ◽  
Sea Water ◽  
Tritiated Water ◽  
Water Flux ◽  
Harbor Seals ◽  
Total Water ◽  
Total Chloride ◽  
Definitive Evidence ◽  
Water Ingestion ◽  
Terrestrial Mammals

Harbor seals maintained in sea water were either starved or fed graded amounts of herring of known water and total chloride contents. Total body water and exchangeable chloride in the seals were measured by initial dilution of injected tritiated water and Na36Cl. The decline in specific activities of plasma water and chloride was then followed for 12 to 14 days. Average daily fluxes of water and Cl− were calculated. Sea water ingestion was calculated from the daily chloride flux and the chloride contents of the food and sea water. In five animals fed from 0 to 1500 g herring/day, total water flux was linearly related to food intake and ranged from 500 to 1590 ml water per day. In the same animals ingested sea water and metabolic plus inspired water were also linearly related to food intake, and ranged respectively from 35 to 140 ml and 470 to 625 ml water per day. The data provide definitive evidence that starving Harbor seals derive sufficient oxidative water to satisfy the major part of their needs and that they drink very little sea water. In feeding seals the sum of preformed water and metabolic plus inspired water accounts for about 90% of the total water flux, which is comparable in magnitude to that of most terrestrial mammals. The small volume of sea water ingested by Harbor seals, and its linear relationship to food intake, show compellingly that sea water ingestion is coincident to swallowing food under water rather than due to deliberate drinking.

scholarly journals Sodium and Water Balance in the Cichlid Teleost, Tilapia Mossambica

1967 ◽  
Vol 47 (3) ◽  
pp. 461-470 ◽  
Author(s):  
W. T. W. POTTS ◽  
M. A. FOSTER ◽  
P. P. RUDY ◽  
G. PARRY HOWELLS
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sea Water ◽  
Tritiated Water ◽  
Sodium Influx ◽  
Water Drinking ◽  
Body Sodium ◽  
Total Body ◽  
Sodium And Water Balance ◽  
Total Sodium

1. The total body sodium increases from 45.9 µM/g. fish in fresh water to 59.9 µM/g. fish in 200 % sea water. 2. The rate of exchange of sodium increases from 2 µM/g./hr. in fresh water to 60 µM/g./hr. in 100% sea water. 3. The rate of drinking increases from 0.26%/hr. fresh water to 1.6%/hr. in 400% sea water. Even in 200% sea water drinking accounts for only a quarter of the total sodium influx. 4. The permeability to water, as measured by tritiated water, is highest in fresh water and lowest in 200% sea water. The permeabilities to water measured in this way are consistent with the drinking rates determined in sea water and 200% sea water.

Water and Energy-Metabolism and Estimated Food-Consumption Rates of Free-Living Wambengers, Phascogale-Calura (Marsupialia, Dasyuridae)

1989 ◽  
Vol 16 (5) ◽  
pp. 501 ◽  
Author(s):  
B Green ◽  
D King ◽  
a Bradley
Keyword(s):  
Adult Population ◽  
Accidental Poisoning ◽  
Metabolic Rates ◽  
Water Fluxes ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Water Influx ◽  
Exotic Pests ◽  
Consumption Rates ◽  
Lactating Females

The metabolic rates and water fluxes of free-living Phascogale calura were determined with doubly labelled water. The highest rates of water influx occurred in October, when the adult population consisted of lactating females only. The highest metabolic rates occurred in June, and the lowest rates of both water influx and metabolism occurred in March. The value of the data in designing toxic baits for the control of foxes or other exotic pests, while minimising the hazard to phascogales of accidental poisoning, is discussed.

Studies on Ionic Regulation in Carcinus Maenas (L.)

1961 ◽  
Vol 38 (1) ◽  
pp. 135-152
Author(s):  
J. SHAW
Keyword(s):  
Body Weight ◽  
Sea Water ◽  
Carcinus Maenas ◽  
Sodium Concentration ◽  
Sodium Balance ◽  
Uptake Mechanism ◽  
Sodium Influx ◽  
Urine Production ◽  
Sodium Loss ◽  
Total Sodium

1. The mechanism of sodium balance in Carcinus maenas has been investigated. 2. Measurements of sodium outflux showed no evidence of a decrease in surface permeability to sodium in dilute sea water. 3. The rate of urine production in normal sea water was 3.6% body weight per day and the sodium loss through the urine was insignificant compared with the total sodium loss. In 40% sea water the urine rate was increased to 30% body weight per day and the loss in the urine accounted for 20% of the total loss. 4. Measurements of sodium influx and calculation of the active component showed that the active uptake mechanism was fully saturated at all external concentrations in which the animals could survive. 5. Regulation of the blood sodium concentration is effected largely by the activation of the sodium uptake mechanism. This prevents the blood concentration falling below a critical level as long as the external concentration itself is not too low.

Water and Energy Turnover in a Small Monitor Lizard, Varanus-Acanthurus

1990 ◽  
Vol 17 (6) ◽  
pp. 641 ◽  
Author(s):  
G Dryden ◽  
B Green ◽  
D King ◽  
J Losos
Keyword(s):  
Energy Expenditure ◽  
Consumption Rate ◽  
Metabolic Rates ◽  
Energy Turnover ◽  
Doubly Labelled Water ◽  
Water Influx ◽  
Fresh Food ◽  
Monitor Lizard ◽  
The Mean ◽  
Field Metabolic Rates

The field metabolic rates and water influxes of Varanus acanthurus were determined by means of doubly-labelled water during late spring. The mean metabolic rate was 0.101 +/- 0.032 mL CO2 g-1 h-1, which was equivalent to an energy expenditure of 63 kJ kg-1 day-1 and a fresh food consumption rate of 13.2 g kg-1 day-1. The mean rate of water influx was 15.9 +/- 6.8 mL kg-1 day-1 and it is suggested that up to 30% of water influxes are via pulmo-cutaneous exchange and drinking. It is considered that V. acanthurus is a secretive 'sit and wait' predator and that this accounts for the lower than predicted water influx and metabolic rates of this species.

Descriptive statistics

2017 ◽  
Author(s):  
Andrew Gelman ◽  
Deborah Nolan
Keyword(s):  
Descriptive Statistics ◽  
Metabolic Rates ◽  
World Record ◽  
Linear Combinations ◽  
Record Times ◽  
Starting Point ◽  
Statistics Course ◽  
Scatter Plots ◽  
Economic Indexes ◽  
The Mean

Descriptive statistics is the typical starting point for a statistics course, and it can be tricky to teach because the material is more difficult than it first appears. The activities in this chapter focus more on the topics of data displays and transformations, rather than the mean, median, and standard deviation, which are covered easily in a textbook and on homework assignments. Specific topics include: distributions and handedness scores; extrapolation of time series and world record times for the mile run; linear combinations and economic indexes; scatter plots and exam scores; and logarithmic transformations and metabolic rates.

Leptocephalus energetics: metabolism and excretion

1999 ◽  
Vol 202 (18) ◽  
pp. 2485-2493
Author(s):  
R.E. Bishop ◽  
J.J. Torres
Keyword(s):  
Metabolic Rate ◽  
Energy Budget ◽  
Citrate Synthase ◽  
Sea Water ◽  
Negative Slope ◽  
Ion Pump ◽  
Metabolic Rates ◽  
Energy Reserves ◽  
Developmental Strategy ◽  
Juvenile Form

Leptocephali are the unusual transparent larvae that are typical of eels, bonefish, tarpon and ladyfish. Unlike the larvae of all other fishes, leptocephali may remain in the plankton as larvae for several months before metamorphosing into the juvenile form. During their planktonic phase, leptocephali accumulate energy reserves in the form of glycosaminoglycans, which are then expended to fuel metamorphosis. The leptocephalus developmental strategy is thus fundamentally different from that exhibited in all other fishes in two respects: it is far longer in duration and energy reserves are accumulated. It was anticipated that the unusual character of leptocephalus development would be reflected in the energy budget of the larva. This study describes the allocation of energy to metabolism and excretion, two important elements of the energy budget. Metabolic rates were measured directly in four species of leptocephali, Paraconger caudilimbatus, Ariosoma balearicum, Gymnothorax saxicola and Ophichthus gomesii, using sealed-jar respirometry at sea. Direct measurements of metabolic rates were corroborated by measuring activities of lactate dehydrogenase and citrate synthase, two key enzymes of intermediary metabolism, in addition to that of Na(+)/K(+)-ATPase, a ubiquitous ion pump important in osmotic regulation. Excretion rates were determined by subsampling the sea water used in the respiratory incubations. The entire premetamorphic size range for each species was used in all assays. Mass-specific oxygen consumption rate, excretion rate and all enzyme activities (y) declined precipitously with increasing mass (M) according to the equation y=aM(b), where a is a species-specific constant and −1.74<b<-0.44. In leptocephali, the highly negative slope of the familiar allometric equation describing the relationship between mass-specific metabolic rate and mass, normally between −0.33 and 0, showed that a massive decline in metabolic rate occurs with increasing size. The result suggests that the proportion of actively metabolizing tissue also declines with size, being replaced in large measure by the metabolically inert energy depot, the glycosaminoglycans. Leptocephali can thus grow to a large size with minimal metabolic penalty, which is an unusual and successful developmental strategy.

Sodium Regulation in the Amphipod Gammarus Duebeni Lilljeborg form Freshwater Localities in Ireland

1968 ◽  
Vol 48 (2) ◽  
pp. 339-358
Author(s):  
D. W. SUTCLIFFE ◽  
J. SHAW
Keyword(s):  
Fresh Water ◽  
Loss Rate ◽  
Sea Water ◽  
Detailed Comparison ◽  
Urine Concentration ◽  
Sodium Influx ◽  
Fresh Waters ◽  
Low Sodium ◽  
Characteristic Features ◽  
Sodium Regulation

1. A quantitative study of sodium influx and loss was made on populations of Gammarus duebeni obtained from four freshwater localities in Ireland. 2. Characteristic features of sodium regulation in animals from the four localities were as follows, (a) The sodium influx increases gradually with increasing external sodium concentrations, but a maximum (saturation) level is abruptly reached at an external concentration of 1-2 mM/l. and the transporting system is half saturated at about 0.5 mM/l. sodium, (b) Over the range of sodium concentrations found in fresh waters a low rate of sodium uptake is sufficient to balance sodium losses at concentrations down to between 0.5 and 0.25 mM/l. At lower concentrations the influx is increased and the loss rate is reduced. (c) Calculations suggest that hypotonic urine containing approximately 40 mM/l sodium is produced at external concentrations ranging from fresh water to 40 % sea water. At external concentrations below 0.25 mM/l. sodium the urine concentration is probably reduced to well below 40 mM/l. sodium. 3. A detailed comparison is made of sodium regulation at external concentrations ranging between 0.07 and 1 mM/l. sodium in G. duebeni from fresh water in Ireland and from fresh water and brackish water in Britain. It is suggested that G. duebeni in Ireland constitutes a distinct physiological race adapted for living in fresh waters with relatively low sodium concentrations.

scholarly journals Objective measurement of physical activity in Macaca fascicularis

1982 ◽  
Vol 16 (3) ◽  
pp. 240-243
Author(s):  
Wayne T. Corbett ◽  
Harry M. Schey ◽  
A. W. Green
Keyword(s):  
Physical Activity ◽  
Standard Deviation ◽  
Macaca Fascicularis ◽  
Living Environment ◽  
Activity Levels ◽  
Free Living ◽  
Activity Measurements ◽  
Active Intermediate ◽  
The Mean ◽  
The Relationship

The mean and standard deviation over 24 h for 3 groups of animals - active, intermediate and inactive - in physical activity units were 10948 ± 3360, 2611 ± 1973 and 484 ± 316 respectively. The differences were significant ( P = 0·004), demonstrating the ability of the method to distinguish between groups that can be visibly differentiated. The small within-animal physical activity standard deviation (18·85 PAU) obtained in another group, suggests that it also yields reliable physical activity measurements for non-human primates. The monitoring device used can discriminate between individual nonhuman primate physical activity levels in a free-living environment and does not alter daily behaviour. This makes possible the study of the relationship between physical activity and atherosclerosis in nonhuman primates.

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