scholarly journals The Respiratory Rate of Gammarus chevreuxi in Relation to Differences in Salinity

1935 ◽  
Vol 12 (3) ◽  
pp. 217-221
Author(s):  
OTTO LÖWENSTEIN
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Respiratory Rate ◽  
Brackish Water ◽  
Sea Water ◽  
Natural Habitat ◽  
Freshwater Species ◽  
Percentage Decrease ◽  
Rate Of Oxygen Consumption

1. The rate of oxygen uptake was studied in the brackish water amphipod Gammarus chevreuxi in water of different salinities (25 per cent, sea water and sea water). The respiratory rate was found to be approximately 20 per cent, lower in sea water than in 25 per cent, sea water which is a concentration occurring in the natural habitat. Anaesthetised animals showed the same percentage decrease as unanaesthetised animals. 2. The change in oxygen consumption takes place immediately after the transfer and remains constant thereafter. It is completely reversible. 3. A comparison with the unanaesthetised respiratory rates of the related freshwater species G. pulex and marine G. marinus shows that the rate of oxygen consumption of the brackish water form G. chevreuxi in 25 per cent, sea water lies between the two others.

scholarly journals Oxygen Consumption as a Function of Size and Salinity in Metapenaeus monoceros Fab. From Marine and Brackish-Water Environments

1958 ◽  
Vol 35 (2) ◽  
pp. 307-313
Author(s):  
KANDULA PAMPAPATHI RAO
Keyword(s):  
Oxygen Consumption ◽  
Brackish Water ◽  
Sea Water ◽  
Regression Coefficient ◽  
Tap Water ◽  
Osmotic Regulation ◽  
Osmotic Adaptation ◽  
Metapenaeus Monoceros ◽  
Rate Of Oxygen Consumption ◽  
Two Populations

1. The oxygen consumption in relation to the salinity of the medium has been studied in a marine and a brackish-water population of the prawn, Metapenaeus monoceros Fab. 2. It has been shown that the regression coefficient of oxygen consumption against weight is not the same for media of different salinity and for the two populations. 3. In both the groups of prawns an increase in the oxygen consumption was observed, with a decrease in the salinity of the medium below that of the habitat. But the marine prawns showed higher rates in 50 and 25% sea water compared to the brackish-water prawns. On the other hand, the brackish-water prawns exhibited a higher rate of oxygen consumption in 100% sea water and in tap water. 4. It is suggested that these differences might be due to (i) an osmotic adaptation, and (ii) the operation of a metabolic homoeostatic mechanism in relation to osmotic regulation.

The relationship between cirral activity and oxygen uptake in Balanus balanoides

1965 ◽  
Vol 45 (2) ◽  
pp. 387-403 ◽  
Author(s):  
R. C. Newell ◽  
H. R. Northcroft
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Mantle Cavity ◽  
The Body ◽  
Effect Of Temperature ◽  
Zero Rate ◽  
Rate Of Oxygen Consumption ◽  
The Relationship ◽  
Balanus Balanoides

The rate of cirral beat of Balanus balanoides is related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.Balanus balanoides exhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.

Osmotic balance and respiration in the hermit crab, Pagurus bernhardus, exposed to fluctuating salinities

1978 ◽  
Vol 58 (4) ◽  
pp. 869-876 ◽  
Author(s):  
Sandra E. Shumway
Keyword(s):  
Oxygen Consumption ◽  
Sea Water ◽  
External Medium ◽  
Temporary Increase ◽  
Tissue Water ◽  
Low Salinity ◽  
Significant Difference ◽  
Rate Of Oxygen Consumption ◽  
Osmotic Balance ◽  
Pagurus Bernhardus

Specimens of Pagurus bernhardus (with and without shells) were exposed to both gradual (sinusoidal) and abrupt (square-wave) salinity fluctuations and changes in haemolymph osmolality, tissue water content and oxygen consumption monitored. Oxygen consumption was also monitored under steady-state conditions; under these conditions there was no significant difference between the rate of oxygen consumption by animals with shells and animals without shells. Oxygen consumption was found to vary with body weight according to the equation O2 consumption = 0·292 W0·668. During exposure to fluctuating salinities the crabs with shells were seen to increase loco-motory activity when the external medium declined to approximately 75% sea water. Haemolymph osmolality values followed the same pattern of change as the external medium; the haemolymph of crabs without shells became significantly more dilute during exposure to low salinity than did that of crabs with shells. P. bernhardus showed significant increases and decreases in hydration level as salinities fell and rose respectively. Crabs with shells showed a marked temporary increase in oxygen consumption when the external medium declined to approximately 75% sea water; crabs without shells showed no such response. The importance of the shell as a means of protection against dilute media is discussed.

RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: III. INFLUENCE OF OXYGEN

1964 ◽  
Vol 42 (3) ◽  
pp. 355-366 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Partial Pressure ◽  
Brook Trout ◽  
Low Oxygen ◽  
Low Level ◽  
Standard Metabolism ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate

Standard oxygen consumption was determined in relation to various partial pressures of oxygen for eastern brook trout at 10° and 15 °C, and for carp and goldfish at 10° and 20 °C. Two conditions of oxygen acclimation were compared. In one case acclimation was to air saturation while in the other acclimation was to each of the partial pressures of oxygen applied.Down to a partial pressure of oxygen of approximately 80 mm Hg, standard oxygen uptake remained approximately constant, and further, the rates for the two differently acclimated groups were about equal. Below 80 mm Hg the standard rate first increased to a maximum and then, with a further reduction in the partial pressure, decreased. Below 80 mm Hg the standard rate of oxygen consumption was in all cases less for the fish acclimated to the low level of oxygen than for those acclimated to air saturation.Comparison of standard and active values suggests that the increase in standard rate of oxygen uptake in response to low oxygen does not reach the active level as suggested earlier by Fry (1947). The suggestion is made that a fraction of standard metabolism is derived anaerobically in low levels of oxygen. Further, it appears that acclimation to a low level of oxygen enhances the anaerobic fraction of standard metabolism.

The Oxygen Consumption of Flies During Flight

1940 ◽  
Vol 17 (4) ◽  
pp. 402-407 ◽  
Author(s):  
R. A. DAVIS ◽  
G. FRAENKEL
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Lucilia Sericata ◽  
Pure Oxygen ◽  
Blow Fly ◽  
Significant Difference ◽  
Rate Of Oxygen Consumption ◽  
Wet Weight

A method is described by which the oxygen uptake of the blow-fly, Lucilia sericata Mg., was measured during flight manometrically in a Warburg and in a Barcroft type of apparatus. The average oxygen consumption in air for all the flies used was 95·580 c.c. per g. wet weight per hour. When flying in pure oxygen the rate of oxygen consumption showed no significant difference; in oxygen-nitrogen mixtures, containing 10 and 5% oxygen, the rate was considerably less than in air.

The Respiratory Physiology of the Marine Nematodes Enoplus Brevis (Bastian) and E. Communis (Bastian)

1973 ◽  
Vol 59 (1) ◽  
pp. 267-274
Author(s):  
H. J. ATKINSON
Keyword(s):  
Oxygen Consumption ◽  
Sea Water ◽  
Atmospheric Oxygen ◽  
Respiratory Physiology ◽  
Marine Nematodes ◽  
Oxygen Regime ◽  
Lower Oxygen ◽  
Rate Of Oxygen Consumption ◽  
Oxygen Tensions ◽  
Oxygen Requirements

1. The rate of oxygen consumption of individual male Enoplus brevis and E. communis was measured at 15 °C, after altering the oxygen regime experienced since the animals were collected. 2. When both E. brevis and E. communis were transferred to 35 Torr from atmospheric oxygen tensions, their oxygen consumption was only two-thirds of that of individuals maintained at this lower oxygen tension. 3. The rate of oxygen consumption of the two species at 135 Torr was unaltered by exposure for 2 h to oxygen-free sea water. 4. The results are discussed in relation to the overall influence of fluctuating oxygen regimes on the oxygen requirements of nematodes.

Oxygen Consumption of Castrated Females of the Blow-Fly, Calliphora Erythrocephala Meig

1955 ◽  
Vol 32 (4) ◽  
pp. 692-699
Author(s):  
ELLEN THOMSEN ◽  
KIRSTEN HAMBURGER
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Corpus Allatum ◽  
Blow Fly ◽  
Calliphora Erythrocephala ◽  
Rate Of Oxygen Consumption ◽  
The Individual

1. The oxygen uptake of castrated females of Calliphora was measured and found to be of the same order as that of the ‘operated controls’, i.e. females operated upon in the same way except that their ovaries were not removed. This result confirms the conclusion drawn from previous experiments (Thomsen, 1949), viz. that the influence of the corpus allatum on the oxygen consumption works independently of the presence or absence of the ovaries. 2. However neither in castrated nor in normal females could any correlation be found between the size of the individual corpus allatum and the rate of oxygen consumption of the fly.

The Physiology of Sea-Urchin Spermatozoa

1952 ◽  
Vol 29 (1) ◽  
pp. 66-71
Author(s):  
LORD ROTHSCHILD ◽  
K. W. CLELAND
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Sea Urchin ◽  
Sea Water ◽  
Dry Weight ◽  
Arithmetic Mean ◽  
Middle Piece ◽  
Oxidative Breakdown ◽  
Principal Source ◽  
Fresh Semen

1. Sea-urchin spermatozoa (Echinus esculentus) contain 4·14 mg. phospholipid per 1010 spermatozoa (arithmetic mean of five replicated experiments, standard error 0·06). This amount of phospholipid is about 5·5% of the dry weight of a sea-urchin spermatozoon. 2. The seminal plasma contains very small quantities of phospholipid, about 20 mg./100 ml., less than one-thirtieth the content of fresh semen. 3. When sea-urchin semen was diluted 1:20 with sea water and the spermatozoa incubated aerobically for some 7 hr.at 20°C., phospholipid disappeared. The average disappearance per 1010 spermatozoa was 19·0% (S.E. 2·4), while the corresponding oxygen uptake of the same sperm suspensions during the same time was 1·450 ml. (S.E. 0·118). The oxidation of glycogen or glycogen-like material was found to be entirely insufficient to account for the observed oxygen consumption. 4. Assuming that the combustion of 1 mg. phospholipid requires 1·6 ml. oxygen, the ratio of the theoretical oxygen uptake (associated with the observed disappearance of phospholipid) to the observed oxygen uptake was 0·86 (S.E. 0·04). 5. It is concluded that the oxidative breakdown of phospholipid, located in the middle-piece, is the principal source of the energy required for movement.

Oxygen dependence of respiration in coupled and uncoupled endothelial cells

1996 ◽  
Vol 271 (6) ◽  
pp. C2053-C2061 ◽  
Author(s):  
R. Steinlechner-Maran ◽  
T. Eberl ◽  
M. Kunc ◽  
R. Margreiter ◽  
E. Gnaiger
Keyword(s):  
Endothelial Cells ◽  
Oxygen Consumption ◽  
Respiratory Rate ◽  
Oxygen Diffusion ◽  
Umbilical Vein ◽  
Carbonyl Cyanide ◽  
Coupled Cells ◽  
Rate Of Oxygen Consumption ◽  
Cell Densities ◽  
Umbilical Vein Endothelial Cells

We studied the oxygen dependence of respiration in cultured human umbilical vein endothelial cells by use of high-resolution respirometry. The rate of oxygen consumption varied from 30 to 50 pmol O2.s-1.(10(6) cells)-1 over a sixfold range of cell densities. Respiration was stimulated up to 3.5-fold by uncoupling with carbonyl cyanide p-trifluoromethoxyphenylhydrazone or 2,4-dinitrophenol, and the PO2 at half-maximal respiration (P50) increased from 0.05 to 0.12 kPa (0.3 to 0.9 Torr) with respiratory rate. P50 decreased to a minimum of 0.02 kPa when uncoupled cells were inhibited to control levels. Differences in cell size explained a variation of approximately 0.015 kPa in P50 at similar respiratory rates per cell. Oxygen diffusion to mitochondria contributed maximally 30% to the regulation of P50 in coupled cells, as deduced from the shallow slope of the flux dependence of P50 in uncoupled-inhibited cells compared with the slope in coupled cells. Therefore 70% of the flux dependence of P50 in coupled cells was caused by changes in metabolic state, which correlated with respiratory rate.

The oxygen uptake of Trypanosoma lewisi and Trypanosoma equiperdum, with especial reference to oxygen consumption in the presence of amino-acids

Parasitology ◽  
1958 ◽  
Vol 48 (1-2) ◽  
pp. 149-164 ◽  
Author(s):  
June P. Thurston
Keyword(s):  
Amino Acids ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Yeast Extract ◽  
Casein Hydrolysate ◽  
Phosphate Solution ◽  
Trypanosoma Lewisi ◽  
Rate Of Oxygen Consumption

1. Standard conditions are described for preparing suspensions of washed Trypanosoma lewisi and T. equiperdum in modified Ringer–phosphate solution.2. Oxygen consumption was measured with differential manometers, using microflasks containing 2–5 × 107 trypanosomes in 0·9 ml. of reaction mixture. Measurements of oxygen uptake were carried out at 37° C.3. T. lewisi respired slowly in the absence of substrate for up to 2 hr. The trypanosomes suffered little damage when stored at 5° C. for 24 hr. without substrate. No oxygen uptake was observed with T. equiperdum in the absence of substrate. The trypanosomes were viable after 24 hr. at 5° C. with glucose or glycerol as substrate, but not in the absence of substrate.4. With glucose as substrate, the rate of oxygen consumption by T. lewisi increased with the age of infection. This change was more marked with glutamine as substrate.5. With glucosamine as substrate, the oxygen uptake of T. lewisi was at a slightly lower rate than with glucose. The rate of oxygen uptake was still lower with Na l-glutamic acid, asparagine, aspartic acid, casein hydrolysate, yeast extract and Difco Bacto-peptone. Thirteen other amino-acids had no effect on the motility of the trypanosomes.6. With glycerol as substrate, the oxygen uptake of T. equiperdum was at a slightly lower rate than with glucose. The rate of oxygen uptake was very low with yeast extract, casein hydrolysate and Difco Bacto-peptone. No oxygen uptake or motility was recorded with glutamine, Na l-glutamic acid, glucosamine, asparagine, aspartic acid, dl-alanine, or Na acetate. Thirteen other amino-acids had no effect on the motility of the trypanosomes.7. Ammonia was liberated from glutamine by adult and reproductive phase T. lewisi.

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