The Relation of Oxygen Consumption to Body Size and to Temperature in the Larvae of Chironomus Riparius Meigen

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.

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.


1960 ◽  
Vol 37 (4) ◽  
pp. 706-718
Author(s):  
R. W. EDWARDS ◽  
M. A. LEARNER

1. The oxygen-consumption rates of Asellus aquaticus (males and females) have been measured at 10 and 20° C. using a constant-volume respirometer, and the effect of starvation for 24 hr. investigated. The oxygen consumption is approximately proportional to the 0.7 power of the wet weight. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 1.5. 2. The oxygen-consumption rates of A. aquaticus and A. meridianus have been measured at 20° C. in a flowing-water respirometer employing a polarographic technique for the measurement of dissolved-oxygen concentrations. The oxygen consumptions of A. aquaticus and A. meridianus are similar and decrease by 15-20% when the dissolved-oxygen concentration falls from 8.3 to 1.5 p.p.m. 3. The oxygen consumption of A. aquaticus is between 35 and 75% higher in the polarographic respirometer than in the constant-volume respirometer.


1973 ◽  
Vol 59 (1) ◽  
pp. 255-266
Author(s):  
H. J. ATKINSON

1. The rate of oxygen consumption of individual males of Enoplus brevis and E. communis was measured at 15 °C and at each of four oxygen tensions, 135, 75, 35, and 12 Torr, after at least 12 h experience of these conditions. 2. It was clearly demonstrated that the level of oxygen consumption of both species was reduced by each lowering of the imposed oxygen tension. 3. In all cases the oxygen consumption of each species fell with increasing body size. On a unit dry-weight basis the oxygen consumption of E. brevis is greater than that of the larger E. communis, but after allowing for the difference of body size the two species have more or less similar oxygen uptakes at all oxygen tensions. 4. In E. brevis oxygen tension influenced the relationship of body size and metabolism, the slope relating oxygen consumption and body weight becomes steeper with decreasing oxygen tension. This effect was not shown by E. communis. 5. Some general factors influencing the availability of oxygen to nematodes are considered.


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.


1979 ◽  
Vol 78 (1) ◽  
pp. 213-223
Author(s):  
DAVID F. MOFFETT

Potassium transport by the isolated midgut of Manduca larvae, as measured by the short circuit current, is inhibited by substitution of small organic solutes (M.W. < 340) for the sucrose normally included in bathing solution formulated for this tissue. Other solutes of molecular weight equal to or greater than sucrose are essentially as effective as sucrose in promoting the short circuit current. Equilibration of midgut in solutions containing the small solute mannitol results in a decrease in the dry weight/wet weight ratio of the tissue, suggesting that the small solutes can penetrate into areas of the tissue which are not accessible to sucrose. Histological studies suggest that sites of swelling in the presence of mannitol include both cytoplasm and goblet cell lumen. The inhibition of the short circuit current is rapidly reversible on return to bathing solution containing sucrose or another large solute. The effect of small solutes probably does not involve compromise of the energy source for potassium transport since oxygen uptake is unchanged in the presence of a small solute.


1957 ◽  
Vol 35 (3) ◽  
pp. 195-202 ◽  
Author(s):  
M. A. A. Vonk ◽  
L. W. McElroy ◽  
R. T. Berg

Four treatments, involving differences in method of feeding and interval between last feed and slaughter, were employed in a study of the effect of dietary chlortetracycline on protease, amylase, and cellulase activity in the intestinal and cecal contents of 16 pairs of weanling pigs. Most consistent results were obtained with six pairs which were limited pair-fed except for the final feeding during which feed was available ad libitum for a 4-hour period ending 18 hours before slaughter. The mean total activities of all three hydrolases in the contents of the small intestines and of the ceca of the antibiotic-fed animals of these six pairs were significantly greater than in those of the control animals. Expressed as activity per gram dry matter of intestinal contents, significantly higher values for protease and amylase, but not for cellulase, were observed in the pigs that had received chlortetracycline. When the combined results obtained from all 16 pairs of the experimental animals were analyzed, the results showed that on a basis of activity per gram dry matter of intestinal contents, ingested chlortetracycline was associated with significant increases in amylase and cellulase but not in protease activity. Protease, amylase, and cellulase activities per gram dry matter of cecal contents were higher for pigs fed the antibiotic than for their controls. The mean wet weight of the empty small intestine and the mean dry weight of the mucosa scraped from the anterior 3-meter section of the small intestine were lower for the chlortetracycline-fed animals, but the differences were not statistically significant.


2006 ◽  
Vol 100 (4) ◽  
pp. 1224-1229 ◽  
Author(s):  
Elizabeth M. Wagner ◽  
Gulnura Karagulova ◽  
John Jenkins ◽  
John Bishai ◽  
Jessica McClintock

We have shown that left pulmonary artery ligation (LPAL) in mice causes a prompt angiogenic response, with new systemic vessels from intercostal arteries penetrating the pleura within 6 days. Because angiogenic vessels in other organs have been shown to exhibit increased permeability, we studied vascular permeability (Evans blue dye extravasation, lung wet weight-to-dry weight ratio, and lavaged protein) in naive C57BL/6 mice and 4 h, and 14 and 21 days after LPAL (4–6 mice/time point). We also measured radiolabel clearance as an index of functional perfusion after LPAL. Tracer clearance from the left lung was maximal by 6 days after LPAL and not different from right lungs. Thus a functional vasculature is established before 6 days of LPAL that results in normal tracer clearance. By 21 days after LPAL, Evans blue-albumin was significantly increased in the left lung relative to both 4 h (no vasculature) and 14 days after LPAL. Only after 21 days of LPAL was left lung wet weight-to-dry weight ratio significantly different from naive lungs. Additionally, lavaged protein was significantly increased both 4 h and 21 days after LPAL relative to control mice. Thus, using three different methods, results consistently demonstrated increased permeability to protein and water 21 days after LPAL. Although changes in surface area of perfusion might affect the interpretation of these results, blood flow measured with labeled microspheres indicated no change in left lung perfusion between 14 and 21 days of LPAL. Thus the lung vasculature, remodeled as a consequence of chronic pulmonary artery obstruction, demonstrates increased water and protein permeability.


1977 ◽  
Vol 34 (2) ◽  
pp. 225-231 ◽  
Author(s):  
Gareth C. H. Harding

A method is described for estimating the surface area of marine crustaceans. The external surface area of the euphausiid Thysanöessa raschii (M. Sars) is proportional to length2.4, dry weight0.95, and wet weight0.84. Oxygen consumption is proportional to wet weight0.82, which indicates that respiration should be proportional to respiratory surface area. The implications of this finding regarding the relations of metabolic rate, size, and surface area are discussed in a broader framework by comparing them with similar studies on vertebrates and other invertebrates.


2020 ◽  
Vol 7 (3) ◽  
pp. 1111-1119
Author(s):  
Julio Cezar Tannure Faria ◽  
Marcos Vinícius Winckler Caldeira ◽  
William Macedo Delarmelina ◽  
Erick Martins Nieri ◽  
Denys Santana Souza ◽  
...  

In the production of forest seedlings one of the main factors to be analyzed is the formulation of the substrate that meets the needs of the plants that will be produced. For this, the choice of substrate must consider the physical characteristics of the material, its chemical composition, as well as its availability, quality, easy handling and cost. This study aimed to investigate the potential of sewage sludge and rice husk for the production of seedlings of Mimosa setosa. The experiment was conducted in structures of a forest nursery, localized in the municipality of Alegre-ES, in 110 cm³ tubes arranged in a completely randomized design constituted by ten treatments with four replications of 54 seedlings per plot. The treatments were formulated using sewage sludge, raw rice husks and carbonized rice husk. At five months after sowing we measured plant height, root collar diameter, height/diameter ratio, shoot dry weight, root dry weight, total dry matter, shoot to root dry weight ratio and Dickson Quality Index. The substrates formulated with carbonized rice husk promoted the best results for all morphological characteristics analyzed. The multivariate analysis showed higher correlation of treatments with carbonized rice husk (T6, T7, T8 and T9) regarding height, root collar diameter, root dry weight, shoot dry weight and total dry matter. For the production of Mimosa setosa seedlings the best responses resulted from the substrate formulated with 60% sewage sludge + 40% carbonized rice husk.


Sign in / Sign up

Export Citation Format

Share Document