scholarly journals Standardizing the determination and interpretation of Pcrit in fishes

2019 ◽  
Author(s):  
Jessica E. Reemeyer ◽  
Bernard B. Rees
Keyword(s):  
Traditional Approach ◽  
Standard Metabolic Rate ◽  
Intermittent Flow ◽  
Fundulus Grandis ◽  
Line Segments ◽  
Critical Oxygen Tension ◽  
Ambient Oxygen ◽  
Critical Oxygen ◽  
Experimental Trials ◽  
Relationship Of

AbstractFor most fishes, there is an oxygen level, the critical oxygen tension (Pcrit), below which oxygen consumption (MO2) becomes dependent upon ambient oxygen partial pressure (PO2). We compare multiple curve-fitting approaches to estimate Pcrit of the Gulf killifish, Fundulus grandis, during closed and intermittent-flow respirometry. The traditional approach fitting two line segments of MO2 versus PO2 produced high and variable estimates of Pcrit. Nonlinear regression using hyperbolic or Weibull functions resulted in either variable Pcrit estimates or, in some cases, failed to converge upon meaningful solutions. Pcrit determined as the PO2 when MO2 equals standard metabolic rate (SMR) based upon a linear relationship of MO2 and PO2 at low PO2 were consistent across fish and experimental trials. Therefore, we recommend that Pcrit specifically refer to the PO2 below which SMR cannot be maintained. Its determination, therefore, requires accurate measurement of SMR.

scholarly journals Hypoxia tolerance in elasmobranchs. I. Critical oxygen tension as a measure of blood oxygen transport during hypoxia exposure

2011 ◽  
Vol 215 (1) ◽  
pp. 93-102 ◽  
Author(s):  
B. Speers-Roesch ◽  
J. G. Richards ◽  
C. J. Brauner ◽  
A. P. Farrell ◽  
A. J. R. Hickey ◽  
...  
Keyword(s):  
Oxygen Tension ◽  
Oxygen Transport ◽  
Hypoxia Tolerance ◽  
Blood Oxygen ◽  
Hypoxia Exposure ◽  
Critical Oxygen Tension ◽  
Critical Oxygen

Specific inspiratory muscle warm-up enhances badminton footwork performance

2007 ◽  
Vol 32 (6) ◽  
pp. 1082-1088 ◽  
Author(s):  
Hua Lin ◽  
Tom Kwokkeung Tong ◽  
Chuanye Huang ◽  
Jinlei Nie ◽  
Kui Lu ◽  
...  
Keyword(s):  
Random Order ◽  
Inspiratory Muscle ◽  
Inspiratory Pressure ◽  
Test Duration ◽  
Warm Up ◽  
Pressure Threshold ◽  
Mouth Pressure ◽  
Concomitant Reduction ◽  
Experimental Trials ◽  
Relationship Of

The effects of inspiratory muscle (IM) warm-up on IM function and on the maximum distance covered in a subsequent incremental badminton-footwork test (FWmax) were examined. Ten male badminton players were recruited to perform identical tests in three different trials in a random order. The control trial did not involve an IM warm-up, whereas the placebo and experimental trials did involve an IM warm-up consisting of two sets of 30-breath manoeuvres with an inspiratory pressure-threshold load equivalent to 15% (PLA) and 40% (IMW) maximum inspiratory mouth pressure, respectively. In the IMW trial, IM function was improved with 7.8% ± 4.0% and 6.9% ± 3.5% increases from control found in maximal inspiratory pressure at zero flow (P0) and maximal rate of P0 development (MRPD), respectively (p < 0.05). FWmax was enhanced 6.8% ± 3.7%, whereas the slope of the linear relationship of the increase in the rating of perceived breathlessness for every minute (RPB/min) was reduced (p < 0.05). Reduction in blood lactate ([La–]b) accumulation was observed when the test duration was identical to that of the control trial (P < 0.05). In the PLA trial, no parameter was changed from control. For the changes (Δ) in parameters in IMW (n = 10), negative correlations were found between ΔP0 and ΔRPB/min (r2 = 0.58), ΔMRPD and ΔRPB/min (r2 = 0.48), ΔRPB/min, and ΔFWmax (r2 = 0.55), but not between Δ[La–]b accumulation and ΔFWmax. Such findings suggest that the IM-specific warm-up improved footwork performance in the subsequent maximum incremental badminton-footwork test. The improved footwork was partly attributable to the reduced breathless sensation resulting from the enhanced IM function, whereas the contribution of the concomitant reduction in [La–]b accumulation was relatively minor.

scholarly journals Combined Effects of Acute Temperature Change and Elevated pCO2 on the Metabolic Rates and Hypoxia Tolerances of Clearnose Skate (Rostaraja eglanteria), Summer Flounder (Paralichthys dentatus), and Thorny Skate (Amblyraja radiata)

Biology ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 56 ◽  
Author(s):  
Schwieterman ◽  
Crear ◽  
Anderson ◽  
Lavoie ◽  
Sulikowski ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Gulf Of Maine ◽  
Standard Metabolic Rate ◽  
Hypoxia Tolerance ◽  
Intermittent Flow ◽  
Metabolic Rates ◽  
Summer Flounder ◽  
Paralichthys Dentatus ◽  
Clearnose Skate ◽  
Species Specific

Understanding how rising temperatures, ocean acidification, and hypoxia affect the performance of coastal fishes is essential to predicting species-specific responses to climate change. Although a population’s habitat influences physiological performance, little work has explicitly examined the multi-stressor responses of species from habitats differing in natural variability. Here, clearnose skate (Rostaraja eglanteria) and summer flounder (Paralichthys dentatus) from mid-Atlantic estuaries, and thorny skate (Amblyraja radiata) from the Gulf of Maine, were acutely exposed to current and projected temperatures (20, 24, or 28 °C; 22 or 30 °C; and 9, 13, or 15 °C, respectively) and acidification conditions (pH 7.8 or 7.4). We tested metabolic rates and hypoxia tolerance using intermittent-flow respirometry. All three species exhibited increases in standard metabolic rate under an 8 °C temperature increase (Q10 of 1.71, 1.07, and 2.56, respectively), although this was most pronounced in the thorny skate. At the lowest test temperature and under the low pH treatment, all three species exhibited significant increases in standard metabolic rate (44–105%; p < 0.05) and decreases in hypoxia tolerance (60–84% increases in critical oxygen pressure; p < 0.05). This study demonstrates the interactive effects of increasing temperature and changing ocean carbonate chemistry are species-specific, the implications of which should be considered within the context of habitat.

The effect of progressive hypoxia on respiration in the dogfish (scyliorhinus canicula) at different seasonal temperatures

1975 ◽  
Vol 63 (1) ◽  
pp. 117-130 ◽  
Author(s):  
P. J. Butler ◽  
E. W. Taylor
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Oxygen Uptake ◽  
Stroke Volume ◽  
Oxygen Tension ◽  
Acclimation Temperature ◽  
Critical Oxygen Tension ◽  
Critical Oxygen ◽  
Progressive Hypoxia ◽  
Cardiac Stroke Volume

1. Dogfish were acclimated to 7, 12 or 17 degrees C and exposed to progressive hypoxia at the temperature to which they had been acclimated. During normoxia, the Q10 values for oxygen uptake, heart rate, cardiac output and respiratory frequency over the full 10 degrees C range were: 2.1, 2.1, 2.1 and 2.5 respectively. Increased acclimation temperature had no effect on cardiac stroke volume or systemic vascular resistance, although there was a decrease in branchial vascular resistance, pHa and pHv. 2. Progressive hypoxia had no effect on heart rate or oxygen uptake at 7 degrees C, whereas at 12 degrees C and 17 degrees C there was bradycardia, and a reduction in O2 uptake, with the critical oxygen tension for both variables being higher at the higher temperature. Cardiac stroke volume increased during hypoxia at each temperature, such that cardiac output did not change significantly at 12 and 17 degrees C. Neither pHa nor pHv changed significantly during hypoxia at any of the three temperatures. 3. The influence of acclimation temperatures on experimental results from poikilotherms is pointed out. Previously-published results show quantitative differences. 4. The significance of the present results with respect to the functioning and location of oxygen receptors is discussed. It is argued that as the metabolic demand and critical oxygen tension of the whole animal are increased at high acclimation temperatures the same must be the case with the oxygen receptor. This would raise the stimulation threshold and could account for the bradycardia seen during hypoxia becoming manifest at higher values of PI,O2, Pa,O2 and Pv,O2 as the acclimation temperature is raised.

Oxygen Uptake, Critical Oxygen Tension, and Available Oxygen for Three Species of Cave Crayfishes

1999 ◽  
Vol 19 (2) ◽  
pp. 235 ◽  
Author(s):  
Andrew T. Gannon ◽  
Vincent G. Demarco ◽  
Tom Morris ◽  
Michele G. Wheatly ◽  
Yu-Hsing Kao
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Tension ◽  
Critical Oxygen Tension ◽  
Critical Oxygen
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