Effect of Maintained Hypoxic Exposure on the Crayfish Orconectes Rusticus: I. Ventilatory, Acid-Base and Cardiovascular Adjustments

1982 ◽  
Vol 98 (1) ◽  
pp. 119-137 ◽  
Author(s):  
P.R. H. WILKES ◽  
B. R. McMAHON
Keyword(s):  
Cardiac Output ◽  
Oxygen Affinity ◽  
Fold Increase ◽  
Respiratory Alkalosis ◽  
Hypoxic Exposure ◽  
Orconectes Rusticus ◽  
Reduced Pressure ◽  
Dissolved Carbon ◽  
Ambient Oxygen ◽  
Dissolved Carbon Dioxide

Oxygen uptake in the crayfish Orconectes rusticus was maintained at normoxic levels throughout 6 days exposure to an ambient oxygen tension of 45-55 torr. This was attributed to compensatory responses of the ventilatory and cardiovascular pumps. The first 72 h of hypoxic exposure were characterized by a transitory 3-fold increase in both scaphognathite rate and cardiac output above initial normoxic values. During the latter 72 h of hypoxic exposure both scaphognathite pumping and cardiac output were significantly below maximum values but were maintained above initial normoxic levels. Thus, as reflected by the increased convection requirements for both water and haemolymph, the increased scaphognathite and heart activity served to increase oxygen delivery to both the branchial chambers and the tissues. Additionally, the increased branchial ventilation and gill perfusion facilitated removal of dissolved carbon dioxide from the haemolymph, effecting a respiratory alkalosis. The increased haemolymph pH elevated the oxygen affinity of the haemocyanin via the Bohr affect, enabling a greater volume of oxygen to be picked up at the gills by the haemocyanin despite the reduced pressure gradient.

Effect of Maintained Hypoxic Exposure on the Crayfish Orconectes Rusticus: II. Modulation of Haemocyanin Oxygen Affinity

1982 ◽  
Vol 98 (1) ◽  
pp. 139-149
Author(s):  
P.R. H. WILKES ◽  
B. R. McMAHON
Keyword(s):  
Oxygen Affinity ◽  
Respiratory Alkalosis ◽  
Hypoxic Exposure ◽  
Protein Levels ◽  
Ambient Oxygen ◽  
Before And After ◽  
Acid Base Status ◽  
Oxygen Carrying Capacity

Haemolymph Na+, Cl−, K+, Mg2+, Ca2+, Cu2+ and protein levels, in vivo postbranchial acid-base status (total CO2, pH and PCOCO2), in vitro haemolymph buffer value, Bohr value and oxygen affinity were measured before and after a 3½-week period in which control crayfish were maintained at normoxia and experimental crayfish were maintained at an ambient oxygen tension of 50-55 torr. Analysis of haemolymph Cu2+ and protein levels in control and experimental crayfish indicated no increase in haemocyanin and therefore oxygen carrying capacity of the haemolymph. Although the Bohr value was not significantly different between control and experimental crayfish, the haemocyanin oxygen affinity was elevated in the hypoxic crayfish by two mechanisms. The first was dependent upon the haemolymph H+ concentration, i.e. a Bohr shift resulting from a respiratory alkalosis. The second mechanism was independent of haemolymph H+ concentration in that at a given pH haemolymph from experimental crayfish had a significantly higher oxygen affinity. The decrease in p50 probably cannot be attributed to a specific cation effect.

Impact of Dursban and Abate on Microbial Numbers and Some Chemical Properties of Standing Ponds

1975 ◽  
Vol 10 (1) ◽  
pp. 33-41 ◽  
Author(s):  
J. Butcher ◽  
M. Boyer ◽  
CD. Fowle
Keyword(s):  
Carbon Dioxide ◽  
Active Ingredient ◽  
Algal Blooms ◽  
Chemical Properties ◽  
Total Carbon ◽  
Dissolved Carbon ◽  
Photosynthetic Productivity ◽  
Dissolved Carbon Dioxide ◽  
Microbial Numbers

Abstract Eleven small ponds, lined with polyethylene, were used to assess the consequences of applications of *DursbanR at 0.004, 0.030, 0.100 and 1.000 ppm and AbateR at 0.025 and 0.100 ppm active ingredient. The treated ponds showed a more pronounced long-term increase in pH and dissolved oxygen and decreasing total and dissolved carbon dioxide in comparison with untreated ponds. Algal blooms were of longer duration in treated ponds than in controls. Total photosynthetic productivity was higher in treated ponds but bacterial numbers did not change significantly. Photosynthetic productivity was estimated by following the changes in total carbon dioxide.

Strategies and adaptations to aquatic life at high altitude

2017 ◽  
Author(s):  
Dean Jacobsen ◽  
Olivier Dangles
Keyword(s):  
High Altitude ◽  
Environmental Conditions ◽  
Low Temperatures ◽  
Cold Adaptation ◽  
Inorganic Carbon ◽  
Direct Result ◽  
Aquatic Life ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Regulatory Capacity

Chapter 5 is focused on how organisms cope with the environmental conditions that are a direct result of high altitude. Organisms reveal a number of fascinating ways of dealing with a life at high altitude; for example, avoidance and pigmentation as protection against damaging high levels of ultraviolet radiation, accumulation of antifreeze proteins, and metabolic cold adaptation among species encountering low temperatures with the risk of freezing, oxy-regulatory capacity in animals due to low availability of oxygen, and root uptake from the sediment of inorganic carbon by plants living in waters poor in dissolved carbon dioxide. These and more adaptations are carefully described through a number of examples from famous flagship species in addition to the less well-known ones. Harsh environmental conditions work as an environmental filter that only allows the well-adapted species to slip through to colonize high altitude waters.

THE EFFECT OF EXERCISE ON THE CARDIAC OUTPUT AND BLOOD FLOW DISTRIBUTION OF THE LARGESCALE SUCKER CATOSTOMUS MACROCHEILUS

1993 ◽  
Vol 183 (1) ◽  
pp. 301-321 ◽  
Author(s):  
A. S. Kolok ◽  
M. R. Spooner ◽  
A. P. Farrell
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Swimming Performance ◽  
Flow Distribution ◽  
Fold Increase ◽  
Blood Flow Distribution ◽  
Dramatic Decline ◽  
Red Muscle ◽  
Catostomus Macrocheilus ◽  
A Current

Cardiac output (Q.) and blood flow distribution were measured in adult largescale suckers at rest and while swimming. Cardiac output was directly measured using an ultrasonic flowprobe in fish during the summer (16°C), fall (10°C) and winter (5°C). Largescale suckers were adept at holding station against a current without swimming and, when engaged in this behavior, they did not significantly increase Q. relative to that found in fish in still water. When fish began to swim, Q. increased significantly. From 16 to 10°C, the critical swimming speed (Ucrit), maximum Q. and scope for Q. of the suckers did not change. However, from 10 to 5°C all three traits were significantly reduced. Thus, these fish respond to variation in water temperature in two different ways. From 16 to 10°C, the fish compensate perfectly for the change in temperature with respect to cardiac and swimming performance. From 10 to 5°C, however, largescale suckers experience a dramatic decline in cardiac and swimming performance that may be associated with a quiescent overwintering strategy. Blood flow distribution in the fish at rest and while swimming was measured at 16°C using injection of colored microspheres. In the resting fish, over 10 % of the microspheres were recovered from the kidney and over 43 % were recovered from white muscle. When the fish were swimming, there was a 60-fold increase in blood flow to the red muscle while blood flow to all other tissues remained consistent with that at rest.

scholarly journals FORMATION CONDITIONS OF GROUNDWATER OF THE UPPER JURASSIC OF THE CENTRAL REGIONS OF THE ZAURAL MEGAMONOCLYSIS

2021 ◽  
Vol 2 (1) ◽  
pp. 181-190
Author(s):  
Dmitry A. Novikov ◽  
Aleksandr N. Pyrayev ◽  
Fedor F. Dultsev ◽  
Anatoliy V. Chernykh ◽  
Svetlana V. Bakustina ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Isotopic Composition ◽  
Upper Jurassic ◽  
Biogenic Origin ◽  
Dissolved Carbon ◽  
Dissolved Carbon Dioxide ◽  
Oxygen And Hydrogen Isotopes ◽  
Central Regions ◽  
First Results ◽  
Formation Conditions

The article presents the first results of complex isotope-hydrogeochemical studies of reservoir waters of the Upper Jurassic deposits of the central regions of the Zaural megamonoclysis. It was shown that most waters have a narrow distribution of oxygen and hydrogen isotopes (δD from -103.2 to -85.6 ‰ and δO from -15.4 to -12.9 ‰). Some of them have pronounced excursions on the isotopic composition, which indicates a difference in their genesis: from condensate to mixed with ancient infiltrogenic. The isotopic composition of carbon of water-dissolved carbon dioxide (δС from -41.6 to -16.3 ‰) indicates its biogenic origin and the possibility of interstratal flows from overlying horizons.

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