Periodic respiration of gill-breathing fishes

1988 ◽  
Vol 66 (1) ◽  
pp. 182-190 ◽  
Author(s):  
John L. Roberts ◽  
David M. Rowell
Keyword(s):  
Energy Savings ◽  
Open Water ◽  
Freshwater Species ◽  
Jaw Muscles ◽  
Reflex Pathways ◽  
Periodic Respiration ◽  
Gill Ventilation ◽  
Respiratory Centers ◽  
Ram Ventilation ◽  
Respiratory Movements

Rhythmic and arrhythmic patterns of breathing are common among gill-breathing fishes. Irregular, short bouts of apnea occur in most fishes during feeding, while long apneic periods are routine for many open-water fishes such as scombrids, which ram ventilate during cruise swimming. During ram ventilation, the work of gill ventilation is transferred from the respiratory to the swimming musculature, with energy savings due to reductions in drag and inertial losses. Noncontinuous swimmers, such as some benthic and midwater marine and freshwater species, seldom cease rhythmic respiratory movements or resort to ram ventilation. When quiescent, they may adopt patterns of secondary cycling, alternating between respiratory pauses and short periods of rhythmic branchial pumping. Types and locations of chemo- and mechano-receptors that trigger changes in respiratory patterns of fish are being identified, as are the reflex pathways linking them to brainstem respiratory centers. A new mechanoreceptor is described that overlies the adductor mandibulae jaw muscles and may be of use in the modulation of cyclic respiratory movements. Respiratory switching control between rhythmic and ram gill ventilation is discussed.

scholarly journals The use of nocturnal flights for barrier crossing in a diurnally migrating songbird

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Christie D. Lavallée ◽  
Saeedeh Bani Assadi ◽  
Alicia M. Korpach ◽  
James D. Ray ◽  
Jason D. Fischer ◽  
...  
Keyword(s):  
Energy Savings ◽  
Open Water ◽  
Gps Tracking ◽  
Future Research ◽  
Barrier Crossing ◽  
Migration Patterns ◽  
Migration Strategies ◽  
Diurnal Migrant ◽  
Time And Energy ◽  
High Degree

Abstract Background The migration patterns of land birds can generally be divided into those species that migrate principally during the day and those that migrate during the night. Some species may show individual plasticity in the use of day or night flight, particularly when crossing large, open-water or desert barriers. However, individual plasticity in circadian patterns of migratory flights in diurnally migrating songbirds has never been investigated. Methods We used high precision GPS tracking of a diurnal, migratory swallow, the purple martin (Progne subis), to determine whether individuals were flexible in their spring migration strategies to include some night flight, particularly at barrier crossing. Results Most (91%) of individuals made large (sometimes > 1000 km), open-water crossings of the Caribbean Sea and the Gulf of Mexico that included the use of night flight. 32% of all water crossings were initiated at night, demonstrating that night flight is not only used to complete large crossings but may confer other advantages for diurnal birds. Birds were not more likely to initiate crossings with supportive winds, however crossings were more likely when they reduced travel distances. Our results are consistent with diurnal birds using night flight to help achieve time- and energy-savings through ‘short cuts’ at barrier crossings, at times and locations when foraging opportunities are not available. Conclusions Overall, our results demonstrate the use of nocturnal flight and a high degree of individual plasticity in migration strategies on a circadian scale in a species generally considered to be a diurnal migrant. Nocturnal flights at barrier crossing may provide time and energy savings where foraging opportunities are low in an otherwise diurnal strategy. Future research should target how diel foraging and refueling strategies support nocturnal flights and barrier crossing in this and other diurnal species.

scholarly journals The Oxygen Uptake of the Lobster (Homarus Vulgaris Edw.)

1954 ◽  
Vol 31 (2) ◽  
pp. 228-251
Author(s):  
H. J. THOMAS
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Uptake ◽  
Oxygen Concentration ◽  
Sea Water ◽  
Carbon Dioxide Concentration ◽  
Ventilation Rate ◽  
Gill Ventilation ◽  
Increasing Temperature ◽  
The Relationship ◽  
Respiratory Movements

1. In sea water the oxygen uptake of Homarus vulgaris is directly proportional to the oxygen concentration. The relationship applies over the temperature range 6-18°C. 2. Within specified limits of size and condition, oxygen uptake is the same for both sexes. 3. The relative oxygen uptake in sea water decreases as the weight of the animal increases. 4. Oxygen uptake in sea water is effected mainly through the gills. The abdominal swimmerets, however, also serve in respiration and account for approximately 3 % of the total oxygen uptake. 5. In sea water of constant oxygen tension, oxygen uptake increases with increasing temperature. 6. Increase in oxygen uptake with temperature in sea water is mainly brought about by an increase in the gill ventilation rate. In addition, the degree of utilization increases. The relationship is a direct reflexion of the increased metabolic activity. 7. The ventilation rate of gills is unaffected by a decrease of oxygen. 8. The percentage of oxygen extracted by the gills increases as the oxygen concentration of the medium decreases. 9. Under the influence of carbon dioxide respiratory movements become retarded at acidities greater than about pH 7.0 and are completely inhibited at around pH 6.5. At acidities less than pH 7.0 changes in the carbon dioxide concentration are without effect on the rate of the respiratory movements. 10. The oxygen uptake in air, notwithstanding its low level, is directly proportional to temperature. 11. The significance of the above results in relation to the respiratory functions of the blood is discussed.

Cerebral Energy Requirement of Neonatal Rats

1957 ◽  
Vol 188 (2) ◽  
pp. 277-280 ◽  
Author(s):  
Frederick E. Samson ◽  
Nancy A. Dahl
Keyword(s):  
Body Temperature ◽  
Survival Time ◽  
Energy Requirement ◽  
Iodoacetic Acid ◽  
The Body ◽  
Effect Of Temperature ◽  
Neonatal Rats ◽  
Survival Times ◽  
Respiratory Centers ◽  
Respiratory Movements

The survival times of neonatal rats in nitrogen with and without injected iodoacetic acid and at diverse ages and temperatures are presented. It is shown that the survival time in nitrogen is greatly shortened if iodoacetic acid has been injected. Also, in iodoacetic acid treated rats the survival time is decreased with the daily development of the animal; the survival time is lengthened by a decrease in body temperature; the effect of temperature decreases with the daily development of the animal; the logarithm of the survival time has a linear relationship with the body temperature. It is concluded that these survival times are a measure of the energy requirement of the respiratory centers and the influence of age and temperature upon the requirement. A calculation is made which indicates that a deficiency of one micromole of energy-rich phosphate per gram of tissue in the respiratory centers results in the cessation of respiratory movements.

Copenhagen Agreement - A New Paradigm of Climate Problem Solving

2010 ◽  
pp. 115-132 ◽  
Author(s):  
S. Agibalov ◽  
A. Kokorin
Keyword(s):  
Climate Change ◽  
Energy Savings ◽  
Global Climate ◽  
Climate Change Policy ◽  
New Order ◽  
Paradigm Shifts ◽  
New Paradigm ◽  
Energy Efficiency Policy ◽  
Policy Paradigm ◽  
Change Policy

Copenhagen summit results could be called a failure. This is the failure of UN climate change policy management, but definitely the first step to a new order as well. The article reviews main characteristics of climate policy paradigm shifts. Russian interests in climate change policy and main threats are analyzed. Successful development and implementation of energy savings and energy efficiency policy are necessary and would sufficiently help solving the global climate change problem.

Pilot trials of hemicelluloses extraction prior to thermomechanical pulp production: Part 1

TAPPI Journal ◽  
2011 ◽  
Vol 10 (5) ◽  
pp. 21-28 ◽  
Author(s):  
CARL HOUTMAN ◽  
ERIC HORN
Keyword(s):  
Oxalic Acid ◽  
Energy Savings ◽  
Wood Chip ◽  
Strength Properties ◽  
Thermomechanical Pulp ◽  
Sugar Solution ◽  
Bisulfite Treatment ◽  
Pilot Trials ◽  
Pulp Production ◽  
Production Part

Pilot data indicate that wood chip pretreatment with oxalic acid reduced the specific energy required to make thermomechanical pulp. A combined oxalic acid/bisulfite treatment resulted in 21% refiner energy savings and 13% increase in brightness for aspen. A low level of oxalic acid treatment was effective for spruce. Energy savings of 30% was observed with no significant change in strength properties. Adding bisulfite did not significantly increase the brightness of the spruce pulp. For pine, the optimum treatment was a moderate level of oxalic acid, which resulted in 34% energy savings and an increase in strength properties. For all of these treatments 1–3 w/w % carbohydrates were recovered, which can be fermented to produce ethanol. The extract sugar solution contained significant quantities of arabinose.

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