The relative significance of body surface and cloacal respiration in Psolus fabricii (Holothuroidea: Dendrochirotida)

1985 ◽  
Vol 63 (12) ◽  
pp. 2878-2881 ◽  
Author(s):  
Russell R. Hopcroft ◽  
D. Bruce Ward ◽  
John C. Roff

Oxygen consumption at 10 °C was measured for Psolus fabricii, in whole animals and in specimens with the cloaca blocked to prevent use of the respiratory trees. In both sets of experiments, oxygen consumption was exponentially related to body size, but larger animals exhibited a significantly greater proportion of oxygen exchange by cloacal respiration. An animal of 80 g wet weight achieves 75% of its respiratory needs by actively pumping water through the cloaca, whereas body surface respiration alone is calculated to be adequate for a 1.9-g animal. It appears that because of their success in shallow areas of dynamic water motion, adult Psolus depend less than other holothurians on body surface respiration.

1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.


1945 ◽  
Vol 21 (1-2) ◽  
pp. 39-45
Author(s):  
C. ELLENBY

1. A method is described by means of which the surface area of puparia of Drosophila melanogaster may be measured. 2. Measurement of almost 200 puparia showed that the relationship between surface area, per mg., and body weight could best be expressed in the form of the equation S=7.7049-2.1099X, where S=surface area, sq. mm. per mg. wet weight, for prepupae of mean wet weight X mg. As the standard error of estimate, ±0.117, is equal to only 2.2% of the mean surface area per mg., the surface area can be accurately estimated from the wet weight. 3. The prepupal oxygen consumption, per mg. wet weight, is shown to decrease steadily with increasing body weight; with an increase in mean wet weight from 0.847 to 1.700 mg., the oxygen consumption, per mg., decreases by about 50%. 4. Utilizing the above regression equation, the surface area of prepupae of known oxygen consumption was estimated and thus the oxygen consumption per sq. mm. of body surface. These values show no significant variation with increasing body weight, so that it can be concluded that the oxygen consumption of prepupae of D. melanogaster is proportional to the surface area.


1995 ◽  
Vol 7 (1) ◽  
pp. 12-25 ◽  
Author(s):  
Danette M. Rogers ◽  
Kenneth R. Turley ◽  
Kathleen I. Kujawa ◽  
Kevin M. Harper ◽  
Jack H. Wilmore

This study was designed to examine the relationship between oxygen consumption and both body surface area and body mass in children to determine what allometric scaling factors from these variables provide appropriate means of expressing data for this population. These scaling factors were then compared to exponents based on theoretical and animal models to determine if the same relationships were present. Forty-two children (21 boys and 21 girls) 7 to 9 years of age participated in maximal and submaximal treadmill testing. The submaximal V̇O2 to body size relationship proved to be a more appropriate factor to use when scaling V̇O2 than the relationship seen between body size and V̇O2max. Therefore, in this population of children, V̇O2 relative to body surface area or body mass to the power 0.67, demonstrated submaximally, provided a more appropriate means of data expression both statistically and physiologically than the traditional expression of V̇O2 relative to body mass (ml·kg−1·min−1).


1997 ◽  
Vol 45 (1-2) ◽  
pp. 01-10 ◽  
Author(s):  
Phan Van Ngan ◽  
Vicente Gomes ◽  
Paulo S. M. Carvalho ◽  
Maria José de A. C. R. Passos

Routine oxygen consumption of krill was investigated as a general measure of its metabolism and assesses the effects of body size, temperature and starvation on the metabolism. No significant difference in whole animal consllmption was detected after 1,3,5 and 7 days of starvation. The response of metabolism of krill to temperature shows a zone of independence, from 0 to 1°C in which the temperature exerts no effect on metabolism. From 1 to 4°C the metabolism increases rapidly in function of temperature. There was a general increase in oxygen consumption with increasing body wet weight. The equation 'between consumption and wet weight is given by Log Q02 = 2.061+ 0.987xLogW, with r = 0.86. The slope of the regression line b=0.987 is less than unity, indicating that oxygen consllmption per unit weight is greater for the smaller than for the larger krill. Average metabolic rate at O°C of 164 krill is 733.24 l, µlO2g(dry wt)-1h-1. The metabolic rate is of 1129.67 J- µlO2g(dry wt)-1h-1 for small krill (13-19 mg dry weight) and 636.16 J- µlO2g(dry wt)-1h-1 for larger animais (160-169 mg dry weight). The metabülism ofkrill is shown to be related to period of adaptation and types of respirometer. Prolonged adaptation period showed adverse effect on metabolism and average oxygen consumption is almost three times higher in respirometers with stirring device than in simple sealed chambers.


1968 ◽  
Vol 48 (2) ◽  
pp. 427-434
Author(s):  
A. E. BRAFIELD

1. The oxygen consumption of the echiuroid Bonellia viridis has been investigated by means of a continuous-flow polarographic respirometer. 2. The general rate of oxygen consumption per unit dry weight is similar to that characteristic of polychaetes, and declines exponentially with increasing body size. 3. The rate of oxygen consumption rises in the light and falls again if darkness is restored. 4. The oxygen consumption of the isolated proboscis plus that of the isolated body region corresponds closely to that of the entire animal. 5. The oxygen consumption per unit dry weight of the proboscis is considerably higher than that of the body region. 6. The oxygen consumption of an isolated body region increases in the presence of light, but that of an isolated proboscis does not. 7. These findings are discussed in relation to the biology of the animal, observed muscular activity, and the occurrence of the pigment bonellin.


1994 ◽  
Vol 76 (1) ◽  
pp. 314-320 ◽  
Author(s):  
C. L. Marcus ◽  
W. B. Glomb ◽  
D. J. Basinski ◽  
S. L. Davidson ◽  
T. G. Keens

The developmental pattern of ventilatory responses, through childhood and puberty into adulthood, is not known. Therefore we studied hypercapnic (HCVR) and hypoxic ventilatory responses (HOVR) in 59 subjects (29 males and 30 females) 4–49 yr of age, of whom 35 were children ( < 18 yr old). There was a significant correlation between HCVR and weight (r = 0.33, P < 0.02), vital capacity (r = 0.30, P < 0.05), and body surface area (r = 0.30, P < 0.05) but not height (r = 0.22, NS). There was no correlation between HOVR and any of the correcting factors. To account for disparities in body size, volume-related results were scaled for body weight. The HCVR corrected for weight (HCVR/WT) decreased with age (r = -0.57, P < 0.001). HCVR/WT was significantly higher in children than in adults (0.056 +/- 0.024 vs. 0.032 +/- 0.015 l.kg-1 x min-1. Torr end-tidal PCO2-1, P < 0.001). The (tidal volume/inspiratory duration)/weight, respiratory rate, and heart rate responses to hypercapnia were increased in the children, and the CO2 threshold was lower (36 +/- 5 vs. 40 +/- 6 Torr, P < 0.05). Similarly, the HOVR corrected for weight (HOVR/WT) decreased with age (r = 0.34, P < 0.05), and HOVR/WT was significantly higher in children than in adults (-0.035 +/- 0.017 vs. -0.024 +/- 0.016 l.kg-1 x min-1.% arterial O2 saturation-1, P < 0.02). The respiratory rate and heart rate responses to hypoxia were increased in the children. We conclude that rebreathing HCVR and HOVR are higher during childhood than during adulthood.


1975 ◽  
Vol 38 (6) ◽  
pp. 1073-1077 ◽  
Author(s):  
J. S. Hayward ◽  
J. D. Eckerson ◽  
M. L. Collis

Five different behaviors of man while in cold ocean water (9–10 degrees C) were assessed for their effect on rate of progress into hypothermia. With subjects wearing lifejackets, two thermally protective behaviors were studied which reduce exposure to the water of areas of body surface with high relative heat loss potential. One was huddling of three persons and the other a self-huddle behavior (HELP or Heat Escape Lessening Posture). These two behaviors resulted in significant reductions of rectal temperature cooling rate of 66 per cent and 69 per cent, respectively, of that of a control behavior. With no flotation available, two survival swimming behaviors (treading water and drownproofing) were shown to result in significant increases in cooling rate to 134 per cent and 182 per cent, respectively, of the control behavior. Potential swimming distance of subjects wearing a life-jacket was 0.85 miles in water near 12 degrees C before predicted incapacitation by hypothermia. It was concluded that behavioral variables can be of major importance in determining survival time in cold water through modulation of cooling rate associated with other variables such as fatness, body size, and clothing.


1982 ◽  
Vol 101 (1) ◽  
pp. 135-141 ◽  
Author(s):  
H.A. EDWARDS

1. Oxygen consumption of A. aegypti larvae, about 210 mul l g−1 tissue wet weight h−1, does not change when the salinity of the environment is changed. The number of mitochondria in the anal papillae, a salt-absorbing epithelium, increases as the external medium is diluted. There is no difference in oxygen consumption between isolated anal papillae in 0, 2 and 20% sea water. The papillae represent about 5% of body volume and their oxygen consumption is about 2% of the animal's total. The theoretical minimum energy cost of osmoregulation is four orders of magnitude smaller than the measured figure for the anal papillae alone. Osmoregulatory phenomena which would explain the recorded observations are discussed.


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