Influence of environmental factors on respiration of excised tissues of American oysters, Crassostrea virginica (Gmelin)

1971 ◽  
Vol 49 (3) ◽  
pp. 353-360 ◽  
Author(s):  
J. A. Percy ◽  
F. A. Aldrich ◽  
T. R. Marcus

Respiration rates of excised gill, mantle, and adductor muscle of the American oyster, Crassostrea virginica (Gmelin), were measured by the Warburg technique at a number of temperatures and salinities and at various times during the year. Dilution of the seawater medium stimulates gill respiration, has no significant effect on mantle respiration and inhibits adductor muscle respiration. Rate–temperature curves are presented for all three tissues. Respiration rates of gill and mantle declined by about 17% in the autumn, while adductor muscle respiration increased by about 14%. A number of possible explanations for the seasonal changes are discussed.

2020 ◽  
pp. jeb.233072
Author(s):  
Bjarke H. Pedersen ◽  
Hans Malte ◽  
Hans Ramløv ◽  
Kai Finster

Studies of tardigrade biology have been severely limited by the sparsity of appropriate quantitative techniques, informative on a single-organism level. Therefore, many studies rely on motility-based survival scoring and quantifying reproductive success. Measurements of O2 respiration rates, as an integrating expression of the metabolic activity of single tardigrades, would provide a more comprehensive insight into how an individual tardigrade is responding to specific environmental factors or changes in life stages. Here we present and validate a new method for determining the O2 respiration rate (nmol O2 mg−1 hour−1) of single tardigrades under steady state, using O2-microsensors. As an example, we show that the O2 respiration rate determined in MilliQ water for individuals of Richtersius coronifer and of Macrobiotus macrocalix at 22 °C was 10.8±1.8 nmol O2 mg−1 hour−1 and 13.1±2.3 nmol O2 mg−1 hour−1, respectively.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Na Lei ◽  
Juan Li ◽  
Tianqing Chen

AbstractSeasonal changes in respiration and the components of four reconstructed soils (gravel + meteorite + lou; gravel + shale + lou; gravel + sand + lou; and gravel + soft rock + lou) in barren gravel land were monitored using the soil carbon flux measurement system. The results showed that (1) the monthly average respiration rate and the rates of the components in the four reconstructed soils were the highest in summer and lowest in winter. In winter, the monthly average respiration rates of the four reconstructed soils were not different (p > 0.05). In summer, the monthly average respiration rate of the sand or meteorite reconstructed soil was different from that of the other three (p < 0.05). (2) The heterotrophic and autotrophic respiration rates were different between the four reconstructed soils (p < 0.05). The contribution of heterotrophic respiration to total respiration in the four reconstructed soils was greater than that of autotrophic respiration throughout the year. In winter, autotrophic respiration accounts for the smallest proportion of total respiration. As the temperature rises, the proportion of autotrophic respiration to total respiration gradually increases and peaks in summer. In summer, the proportion of heterotrophic respiration in the total respiration is the smallest. With the decrease in temperature, the proportion of heterotrophic respiration in total respiration gradually increases and peaks in winter. (3) The maximum and minimum values of the monthly average respiration rate of the four reconstructed soils coincided with the months of maximum and minimum soil temperature. The soil volumetric water content changed with the amount of precipitation. The correlation between soil respiration and temperature was greater than that between soil respiration and volumetric water content. (4) The correlation in seasonal variation between respiration of the four remodelled soils and hydrothermal factors in the study area can be characterised by an exponential function and power-exponential function.


1997 ◽  
Vol 48 (7) ◽  
pp. 589 ◽  
Author(s):  
Anthony C. Cheshire ◽  
Clive R. Wilkinson ◽  
Stephanie Seddon ◽  
Grant Westphalen

The phototrophic sponge Phyllospongia lamellosa is found to depths of 30 m on Davies Reef. Studies of the photophysiology show that this corresponds to the depth at which the sponge–symbiont system can meet 80% of its daily respiratory carbon needs photosynthetically. Net 24-h production was constant to a depth of 20 m (20 µmol O2 g-1 fresh weight day -1 ) and then decreased to compensatory levels at 25 m. The maintenance of net 24-h production to a depth of 20 m was characterized by reductions in the sub-saturating light intensity (Ik ), indicating increased efficiency of light usage at depth. At depths greater than 20 m the changes in Ik could not compensate for the reduced light intensity. The respiration rate of Phyllospongia (3–5 µmol O2 g-1 fresh weight h-1 ) was significantly greater than that of the heterotrophic sponge Ianthella (2.0–3.6 µmol O2 g-1 fresh weight h-1 ) to an extent that depended on season and location. Respiration rates for both species changed similarly between seasons, being higher in summer. There was no evidence for increased respiration rates in shallower water (<10 m), suggesting that this is not a cause for the reduced occurrence of Phyllospongia in shallow waters.


1960 ◽  
Vol XXXIII (III) ◽  
pp. 428-436 ◽  
Author(s):  
W. N. Holmes

ABSTRACT Relatively large doses of vasopressin administered intraperitoneally to the trout significantly enhanced the kidney respiration rate. In contrast to vasopressin a single dose of oxytocin depressed the kidney Qo2 value. This depression continued throughout the observed 24 hour period after injection. Cortisol enhanced the kidney Qo2 values significantly and to a greater extent than vasopressin. These results are discussed in relation to possible adaptive mechanism in euryhaline species of teleosts.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.


1983 ◽  
Vol 29 (11) ◽  
pp. 1500-1506 ◽  
Author(s):  
B. Söderström ◽  
E. Bååth ◽  
B. Lundgren

Microbial biomass and soil respiration rate decreased after application of 150 kg NH4NO3–N∙ha−1 to different coniferous forest podzols. The decrease was already found 3 months after fertilization and was still evident after 3–5 years. Changes in pH, organic matter, or water content in the soils could not explain the decreases. In laboratory experiments, several unfertilized forest soils were treated with 2 mg of NH4NO3–N or of urea–nitrogen∙g wet soil−1. The ammonium nitrate addition resulted in severe depressions of the respiration rates during and up to 175 days of incubation and the decrease was evident after about 1 week. The urea treatment initially increased the respiration rate of the soils, but this appeared to be a transitory effect.


Author(s):  
I.G. Eskesen ◽  
J. Teilmann ◽  
B.M. Geertsen ◽  
G. Desportes ◽  
F. Riget ◽  
...  

During satellite tagging of harbour porpoises (Phocoena phocoena), heart rate, respiration rate and cortisol value were measured to evaluate stress effects during handling and tagging. Respiration rates were obtained using video recordings, heart rates were recorded and serum cortisol levels were analysed from blood samples. Differences in heart rates, respiration rates and cortisol levels before and during the tagging events were investigated. An overall significant decrease of 31.5% in respiration rate was found during the tagging event period, while mature porpoises respired significantly more often than immature individuals. Though significant differences in heart rates were found for some individuals, no general significant change for all animals was detected. We found no correlation between cortisol concentration and either heart rate or respiration rate, nor did we find any relationships between cortisol and month of year, sex and body length. As high individual variations occurred in response to tagging of harbour porpoises, it is not possible to give general advice based on the factors investigated, on how to reduce stress during handling. However, pouring water over the animal and lowering it into the water seem to stabilize a stressed animal. Therefore, general precaution and individual judgement based on experience is essential when handling wild harbour porpoises.


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