Thermoregulation in Erythrocebus patas: a thermal balance study

A thermal balance study over an ambient temperature (Ta) range of 15-40 degrees C was performed on six nonacclimated patas monkeys (Erythrocebus patas) weighing between 3.9 and 6.0 kg. O2 consumption, CO2 production, mean weighted skin temperature (Tsk), rectal temperature (Tre), respiratory evaporative water loss (Eresp), and total evaporative water loss (Etot) were measured continuously after equilibration at each Ta. Tsk increased as Ta increased, whereas Tre was maintained between 37.6 and 38.4 degrees C at Ta from 15 to 40 degrees C. Total evaporative heat losses increased with increasing Ta to a mean value of 76 W/m2 at 40 degrees C. Eresp was relatively constant and increased from 1.0 to 8.0 W/m2 at 15 and 40 degrees C, respectively. Whole-body conductance was similar to that previously reported for Macaca mulatta except at the highest Ta (40 degrees C), where the values for the patas monkey were significantly lower than those reported for the rhesus monkey (rhesus = 72 W/m2; patas = 33 W/m2). The data demonstrate that the patas monkey can maintain its core temperature within a narrow range over a wide range of Ta values. Additionally, Etot in the patas monkey is significantly higher than what has been reported in other nonhuman primates and approaches that reported in humans.

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Evaporative water loss in domestic fowls and its partition in relation to ambient temperature

The Journal of Agricultural Science ◽

10.1017/s002185960003313x ◽

1976 ◽

Vol 87 (3) ◽

pp. 527-532 ◽

Cited By ~ 46

Author(s):

S. A. Richards

Keyword(s):

Ambient Temperature ◽

Water Loss ◽

Absolute Humidity ◽

Evaporative Water Loss ◽

Linear Functions ◽

Whole Body ◽

Water Vapour Pressure ◽

Evaporative Water ◽

Open Flow ◽

Low Levels

SummaryThe rate of evaporative water loss has been studied in domestic fowls in the ambient temperature range from 0 to 40°C.Results for whole-body evaporation were similar when obtained by the open-flow and direct-weighing methods. At low levels of absolute humidity the rate increased by 0·03 mg/(g.h.°C) from 0 to 22 °C and by 0·17 mg/(g.h.°C) from 23 to 40 °C. Wholebody evaporation decreased with rising ambient water vapour pressure by 0·7 mg/(g.h.kPa).Cutaneous water loss was greater than respiratory water loss below 21 °C; it accounted for 78% of whole-body evaporation at 0 °C, falling to 25% at 40 °C.The rates of respiratory and whole-body evaporation could both be expressed as linear functions of respiratory frequency.

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The role of ambient temperature and body mass on body temperature, standard metabolic rate and evaporative water loss in southern African anurans of different habitat specialisation

PeerJ ◽

10.7717/peerj.7885 ◽

2019 ◽

Vol 7 ◽

pp. e7885 ◽

Cited By ~ 2

Author(s):

Mohlamatsane Mokhatla ◽

John Measey ◽

Ben Smit

Keyword(s):

Body Temperature ◽

Metabolic Rate ◽

Body Mass ◽

Water Loss ◽

Standard Metabolic Rate ◽

Evaporative Water Loss ◽

Evaporative Water ◽

Habitat Specialisation ◽

Wide Range

Temperature and water availability are two of the most important variables affecting all aspects of an anuran’s key physiological processes such as body temperature (Tb), evaporative water loss (EWL) and standard metabolic rate (SMR). Since anurans display pronounced sexual dimorphism, evidence suggests that these processes are further influenced by other factors such as vapour pressure deficit (VPD), sex and body mass (Mb). However, a limited number of studies have tested the generality of these results across a wide range of ecologically relevant ambient temperatures (Ta), while taking habitat use into account. Thus, the aim of this study was to investigate the role of Ta on Tb, whole-animal EWL and whole-animal SMR in three wild caught African anuran species with different ecological specialisations: the principally aquatic African clawed frog (Xenopus laevis), stream-breeding common river frog (Amietia delalandii), and the largely terrestrial raucous toad (Sclerophrys capensis). Experiments were conducted at a range of test temperatures (5–35 °C, at 5 °C increments). We found that VPD better predicted rates of EWL than Ta in two of the three species considered. Moreover, we found that Tb, whole-animal EWL and whole-animal SMR increased with increasing Ta, while Tb increased with increasing Mb in A. delalandii and S. capensis but not in X. laevis. Whole-animal SMR increased with increasing Mb in S. capensis only. We did not find any significant effect of VPD, Mb or sex on whole-animal EWL within species. Lastly, Mb did not influence Tb, whole-animal SMR and EWL in the principally aquatic X. laevis. These results suggest that Mb may not have the same effect on key physiological variables, and that the influence of Mb may also depend on the species ecological specialisation. Thus, the generality of Mb as an important factor should be taken in the context of both physiology and species habitat specialisation.

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Respiratory and cutaneous evaporative water loss at high environmental temperatures in a small bird

Journal of Experimental Biology ◽

10.1242/jeb.199.2.451 ◽

1996 ◽

Vol 199 (2) ◽

pp. 451-457 ◽

Cited By ~ 18

Author(s):

B Wolf ◽

G Walsberg

Keyword(s):

Metabolic Rate ◽

Air Temperature ◽

Water Loss ◽

Heat Dissipation ◽

Evaporative Water Loss ◽

Co2 Production ◽

Evaporative Heat Loss ◽

Evaporative Water ◽

Metabolic Chamber ◽

Air Temperatures

We measured rates of respiratory and cutaneous evaporative water loss as a function of air temperature in a small desert bird, the verdin Auriparus flaviceps. Birds were placed in a two-compartment metabolic chamber that separately collected water evaporated from the bird's head and body. Cutaneous and respiratory evaporative water loss, as well as CO2 production, were measured in resting birds at 2 °C intervals between 30 and 50 °C. Metabolic rate was lowest at 38 °C (19 mW g-1) and increased to 28 mW g-1 at 50 °C. At the lowest air temperature, 30 °C, resting metabolic rate was 34 mW g-1. As air temperature increased from 30 to 50 °C, cutaneous water loss increased from 3.3 to 10.3 mg g-1 h-1 and respiratory water loss increased from 2.1-64.1 mg g-1 h-1. At moderate air temperatures (30-36 °C), water loss was divided almost evenly between respiratory and cutaneous components. As air temperature increased, however, verdins became heavily dependent on respiratory evaporation for heat dissipation. Evaporative water loss data for other species at high air temperatures suggest that partitioning of water loss may follow two different patterns. Evaporative heat dissipation may depend primarily on either cutaneous or respiratory modes of evaporative heat transfer. The physiological mechanisms and functional significance of these contrasting patterns of evaporative heat loss remain unknown.

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Evaporative water loss and the role of cocoon formation in Australian frogs

Australian Journal of Zoology ◽

10.1071/zo98013 ◽

1998 ◽

Vol 46 (5) ◽

pp. 405 ◽

Cited By ~ 28

Author(s):

Philip C. Withers

Keyword(s):

Water Content ◽

Water Loss ◽

High Water ◽

Linear Increase ◽

Evaporative Water Loss ◽

High Water Content ◽

Evaporative Water ◽

Wide Range ◽

Very High

Measurements of evaporative water loss (EWL; mg min-1) and resistance (R; sec cm-1) for various Australian frogs indicate three general allometric patterns: non-cocooned and non-‘waterproof’ frogs with EWL ∝ Mass0.30 and R independent of body mass at about 1–3 sec cm-1, cocooned frogs with EWL reduced about 50–200-fold and R about 50–200 sec cm-1, and ‘waterproof’ frogs with EWL reduced about 5–100- fold and R about 5–100 sec cm-1. Cocooned frogs have an exponential reduction in EWL and fairly linear increase in R over time, corresponding to the temporal addition of layers to the cocoon. The biophysical properties of cocoon are generally similar for various species, although there is some variation in both resistance per thickness (5–20 × 104 s cm-2) and diffusion coefficient (0.4–2.4 × 10 –5 cm2 s-1). The hygroscopic property of frog cocoon resembles that of mammalian stratum corneum, hair and wool, and mucopolysaccharides; there is a slight increase in water content of cocoon over a wide range of humidities but a very steep increase in water content and substantial hydration and swelling at >96% RH. This extreme hygroscopic behaviour of frog cocoon at very high RH may reflect less polymer cross-linking in frog cocoon and its high digestibility. The prevention of over-hydration of frog cocoon in vivo may be attributed to the restriction of high water content to only very high RH (>96%).

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