Development pattern of blood oxygen carrying capacity in rainbow bee-eater nestlings

2006 ◽  
Vol 54 (1) ◽  
pp. 1 ◽  
Author(s):  
Kylie Eklom ◽  
Alan Lill
Keyword(s):  
Carrying Capacity ◽  
Bird Species ◽  
Mass Gain ◽  
Blood Parameters ◽  
Development Stage ◽  
Common Mechanism ◽  
Blood Oxygen ◽  
Hemoglobin Content ◽  
Altricial Birds ◽  
Oxygen Carrying Capacity

Growth profile variation among altricial bird species is reflected in variation in development patterns of parameters influencing blood oxygen carrying capacity (O2Cap). Rainbow bee-eater nestlings develop slowly and their asymptotic mass reaches or exceeds adult levels before undergoing prefledging recession (mass overshoot–recession profile, MOR). Erythrocyte count (RBC), blood hemoglobin content (Hb) and hematocrit (Hct) increased 2.5-fold during development. Hatchlings’ erythrocyte volume closely approximated adult levels and decreased by only 1% during development. Erythrocyte hemoglobin content and concentration also increased minimally. RBC and Hb increased throughout development, but Hct increase was restricted to early development, overlapping the mass-gain period by just 37%. Blood parameters influencing O2Cap did not exceed adult levels and then decline during the mass asymptote–recession development stage. Continuing increase in RBC and Hb at this stage contributed to attaining a fledging O2Cap of adult levels. Results were consistent with there being a common mechanism regulating developmental increase in O2Cap in altricial birds. However, features of this development in bee-eater nestlings variously conformed to the patterns of both species with MOR and species with standard growth profiles. Some features shared with other MOR species also differed in timing or pattern in bee-eater nestlings.

Variation during breeding in parameters that influence blood oxygen carrying capacity in shearwaters

2000 ◽  
Vol 48 (4) ◽  
pp. 347 ◽  
Author(s):  
Cristina Davey ◽  
Alan Lill ◽  
John Baldwin
Keyword(s):  
Carrying Capacity ◽  
Energy Demand ◽  
Blood Parameters ◽  
Aerobic Metabolism ◽  
Egg Laying ◽  
Main Trend ◽  
Breeding Cycle ◽  
Blood Oxygen ◽  
Pattern Of Variation ◽  
Oxygen Carrying Capacity

Parameters that influence blood oxygen carrying capacity (whole-blood haemoglobin content, haematocrit and red blood cell count) were measured in samples of 30 breeding, adult short-tailed shearwaters (Puffinus tenuirostris) on Phillip Island, Victoria at seven key stages of their reproductive cycle. The aim of the investigation was to determine whether variation in blood oxygen carrying capacity during the birds’ 7-month breeding cycle was correlated with variation in the energy demands they experienced or was an incidental by-product of other physiological changes. All the blood parameters varied significantly during breeding, but the pattern of variation was only partly correlated with the likely pattern of changing energy demand imposed on parents by their schedule of breeding activities. The main trend conceivably related to energy demand was that significantly higher values were recorded for these blood parameters during the nestling stage than earlier in the breeding cycle. This could have reflected the high costs of the very long foraging trips undertaken by parents feeding nestlings, but it could also have occurred in preparation for the long migration undertaken soon after breeding finished. It involved an ~10% increase in blood oxygen carrying capacity above the lowest mean value recorded during the breeding cycle and so other mechanisms must also be employed to achieve the increase in aerobic metabolism likely to be required at this stage. The lack of adjustment of blood oxygen carrying capacity to energy demand early in the breeding cycle suggests that either oxygen delivery was not a rate-limiting process for aerobic metabolism at that time or that delivery was enhanced through other mechanisms. At egg laying, females had a lower haematocrit and erythrocyte count than males, which could be attributable to either estrogenic suppression of erythropoiesis or an increase in osmotic pressure of the blood associated with yolk synthesis. Immature, non-breeding birds attending the colony were of similar mass to adults, but did not show the increase in the parameters determining blood oxygen carrying capacity that occurred in adults later in the breeding cycle. Factors other than changing energy requirements (dehydration, burrow hypoxia and differential responsiveness to capture stress) that might have influenced the pattern of variation in blood oxygen carrying capacity of adults during breeding are discussed.

Hematological Aspects of the Thermoacclimatory Process in the Rainbow Trout, Salmo gairdneri

1967 ◽  
Vol 24 (11) ◽  
pp. 2267-2281 ◽  
Author(s):  
Mary Anne DeWilde ◽  
A. H. Houston
Keyword(s):  
Rainbow Trout ◽  
General Problem ◽  
Carrying Capacity ◽  
Packed Cell Volume ◽  
Salmo Gairdneri ◽  
Blood Oxygen ◽  
Hemoglobin Content ◽  
Oxygen Capacity ◽  
Higher Temperature ◽  
Oxygen Carrying Capacity

The blood oxygen capacity of the rainbow trout has been investigated as a function of thermal acclimation in terms of erythrocyte abundance, packed cell volume, hemoglobin concentrations, and mean erythrocytic volume and hemoglobin content. Fish at the lower acclimation temperatures employed (3, 7 C) were characterized by relatively low erythrocyte counts, hematocrits, and hemoglobin levels. Mean erythrocyte volumes tended to be relatively high, whereas mean erythrocytic hemoglobin content was somewhat below that typical of the higher temperature groups. In general, animals held at intermediate temperatures (11, 14, 17 C) showed significant increases in oxygen-carrying capacity by comparison with cold-acclimated fish. Finally trout at 21 C typically had larger numbers of somewhat smaller red cells, more hemoglobin, and higher levels of hemoglobin per erythrocyte than either the low- or intermediate-temperature fish. Significant differences were observed between summer and fall–winter series of trout, particularly with respect to hemoglobin levels. The results are discussed in relation to the general problem of respiratory thermoadaptation.

Development of some aspects of blood oxygen transport in nestling short-tailed shearwaters

1999 ◽  
Vol 47 (5) ◽  
pp. 479 ◽  
Author(s):  
Gudrun Arnold ◽  
John Baldwin ◽  
Alan Lill
Keyword(s):  
Growth Rate ◽  
Carrying Capacity ◽  
Slow Growth ◽  
Haemoglobin Concentration ◽  
Mass Gain ◽  
Blood Oxygen ◽  
Slow Growth Rate ◽  
Nestling Development ◽  
Eastern Australia ◽  
Oxygen Carrying Capacity

Body mass of nestling short-tailed shearwaters (Puffinus tenuirostris) on Phillip Island, south-eastern Australia, increased about twelve-fold over the first 65 of the typical 94 days of development, peaked at 33% above adult mass and then declined to adult levels at fledging. Haematocrit and blood haemoglobin concentration of nestlings were constant throughout the initial phase of rapid mass gain, but increased respectively from 30% to 55% and from 9 to 15 g per 100 mL once asymptotic mass had been attained. The erythrocyte count increased throughout development, but most markedly after attainment of peak mass. Consequently, the estimated 70% increase in blood oxygen carrying capacity during nestling development mostly occurred when mass gain had ceased. At fledging, this capacity was 81% of that of adults shortly before they deserted the colony. Over the course of nestling development, erythrocytes decreased in volume by 20% and became more ellipsoidal, which could potentially increase the rate of oxygen delivery to the metabolising tissues. The pattern of development of blood oxygen carrying capacity differed from those reported for most other altricial birds in that the increase in capacity was not continuous throughout development. We suggest that the relatively delayed development of blood oxygen carrying capacity in shearwater nestlings is permitted by their slow growth rate. It may be adaptive in deferring the costs of producing, and particularly maintaining, large numbers of small erythrocytes. The magnitude of the respiratory problem potentially posed for the nestling by burrow hypoxia may not be great and should in any case be reduced by its slow growth rate and consequently relatively low daily energy requirements.

Activity-related variation in blood parameters associated with oxygen transport and chronic stress in little penguins

2007 ◽  
Vol 55 (4) ◽  
pp. 249 ◽  
Author(s):  
Louise Mortimer ◽  
Alan Lill
Keyword(s):  
Chronic Stress ◽  
Body Condition ◽  
Carrying Capacity ◽  
Condition Index ◽  
Blood Parameters ◽  
Body Condition Index ◽  
Stress Indicators ◽  
Nutrient Demand ◽  
Blood Haemoglobin ◽  
Oxygen Carrying Capacity

Some birds facing energy ‘bottlenecks’ display elevated oxidative metabolism and oxygen delivery to tissues and could be particularly susceptible to chronic stress. We examined whether there was evidence for such trends in little penguins (Eudyptula minor) over the period from breeding to the post-moulting stage and particularly during the onshore moult-fast. Penguin parents contribute equally to incubation, brooding and brood provisioning. A few weeks post-breeding, adults undergo a protracted, terrestrial moult-fast and then make brief visits to the colony during the post-moulting stage. Provisioning nestling(s) and moulting could theoretically be particularly energetically and nutritionally demanding. We determined for adults whether mass, a body condition index and blood parameters influencing vascular oxygen carrying capacity (hematocrit, Hct; whole blood haemoglobin, Hb) and indicating chronic stress (leukocyte count, WBC; heterophil/lymphocyte ratio, H/L) varied from August to May in a manner reflecting likely variation in energy and nutrient demand. Female mass and body condition index decreased significantly between the incubation and guard stages, before returning to incubation levels between the guard and post-guard nestling stages. Both parameters declined to their lowest levels between the post-guard and moult stages, before increasing to levels comparable with those during nestling care between the moult and post-moult stages. Blood parameters in both sexes exhibited temporal variation similar to that in female mass and body condition index, declining to their lowest levels during moult and increasing after the moult to levels comparable with those during breeding. Results indicated that the period of most intense provisioning of nestlings was associated with a decrease in blood oxygen carrying capacity, but no pronounced change in chronic stress indicators. However, the penguin’s moult-fast involved a loss of female body condition and, in both sexes, a reduction in body mass, vascular oxygen carrying capacity and possibly specific immune competence. Thus, regulation of human disturbance in accessible little penguin colonies may be particularly important during moult.

Chronic hypoxia and the cerebral circulation

2006 ◽  
Vol 100 (2) ◽  
pp. 725-730 ◽  
Author(s):  
Kui Xu ◽  
Joseph C. LaManna
Keyword(s):  
Blood Flow ◽  
Carrying Capacity ◽  
Hemoglobin Concentration ◽  
Capillary Density ◽  
Hypoxic Exposure ◽  
Blood Oxygen ◽  
Brain Capillary ◽  
Blood Flow Increase ◽  
Time Courses ◽  
Oxygen Carrying Capacity

Exposure to mild hypoxia elicits a characteristic cerebrovascular response in mammals, including humans. Initially, cerebral blood flow (CBF) increases as much as twofold. The blood flow increase is blunted somewhat by a decreasing arterial Pco2 as a result of the hypoxia-induced hyperventilatory response. After a few days, CBF begins to fall back toward baseline levels as the blood oxygen-carrying capacity is increasing due to increasing hemoglobin concentration and packed red cell volume as a result of erythropoietin upregulation. By the end of 2 wk of hypoxic exposure, brain capillary density has increased with resultant decreased intercapillary distances. The relative time courses of these changes suggest that they are adjusted by different control signals and mechanisms. The CBF response appears linked to the blood oxygen-carrying capacity, whereas the hypoxia-induced brain angiogenesis appears to be in response to tissue hypoxia.

Effects of hypoxia and hyperoxia on oxygen-transfer properties of the blood of a viviparous snake

1996 ◽  
Vol 199 (9) ◽  
pp. 2061-2070
Author(s):  
J Herman ◽  
R Ingermann
Keyword(s):  
Carrying Capacity ◽  
Oxygen Affinity ◽  
Blood Parameters ◽  
Pregnant Female ◽  
Molar Ratio ◽  
Nucleoside Triphosphate ◽  
Red Cell ◽  
Garter Snakes ◽  
Oxygen Carrying Capacity ◽  
Thamnophis Elegans

Red cell oxygen affinity, red cell nucleoside triphosphate (NTP) levels and blood oxygen-carrying capacity were determined for male, nonpregnant and pregnant female, and fetal garter snakes Thamnophis elegans exposed to hypoxia (5 % oxygen) and hyperoxia (100 % oxygen). Male and nonpregnant female snakes were maintained under these conditions for up to 3 weeks and exhibited an apparent maximal change in oxygen affinity after 14 days of hypoxia and hyperoxia. Red cell NTP levels decreased and oxygen affinity increased with exposure to hypoxia, while exposure to hyperoxia promoted an increase in red cell NTP concentrations and a decrease in red cell oxygen affinity in the males. Hyperoxia-exposed nonpregnant females did not show a significant change in oxygen affinity. After 14 days of hypoxia, the pregnant females showed an increase in red cell oxygen affinity which was associated with a decrease in red cell NTP concentration and in the molar ratio of NTP/hemoglobin relative to normoxic controls. Fourteen days of hyperoxia did not result in a change in oxygen affinity of red cells from the pregnant female, but did promote a slight increase red cell NTP concentrations. The blood parameters of fetuses from females exposed to hypoxia or hyperoxia did not differ from those of normoxic control fetuses. The fetuses of females exposed to hypoxia suffered greater mortality, appeared less developed and had a lower average wet mass than the fetuses of normoxic- and hyperoxic-exposed females. Neither hypoxia nor hyperoxia altered the oxygen-carrying capacity of the blood in any group of snake.

Seasonal variation in body mass and blood oxygen carrying capacity of the superb fairy-wren (Malurus cyaneus)

2002 ◽  
Vol 50 (3) ◽  
pp. 313 ◽  
Author(s):  
J. Box ◽  
A. Lill ◽  
J. Baldwin
Keyword(s):  
Body Mass ◽  
Carrying Capacity ◽  
Oxygen Delivery ◽  
Blood Oxygen ◽  
Additional Energy ◽  
Blood Haemoglobin ◽  
Malurus Cyaneus ◽  
Energy Challenge ◽  
Oxygen Carrying Capacity ◽  
Winter Fattening

The responses of small birds to many seasonal energy challenges include enhancement of aspects of aerobic metabolism, sometimes involving an increase in the rate of oxygen delivery to the metabolising tissues. One such mechanism that enhances oxygen delivery seasonally is an increase in blood oxygen carrying capacity. This response is enhanced in birds because of their rapid erythrocyte turnover rate. Some small birds have also evolved winter fattening, which helps them to meet the energy challenge presented by winter conditions. Such adaptations, while well documented for North Temperate birds, have received little attention in birds inhabiting temperate Australia. Over a two-year period, we examined seasonal changes in mass, an approximate indicator of fattening, and the parameters determining blood oxygen carrying capacity in a population of superb fairy-wrens (Malurus cyaneus) in outer Melbourne, Australia. Body mass did not vary significantly seasonally, but haematocrit and whole blood haemoglobin were significantly higher in the breeding season than at other times of year and the erythrocyte count was significantly higher in spring than in autumn. We conclude that the failure of the fairy-wrens to increase mass in winter (i.e. show marked winter fattening) was probably due to the comparative mildness of the climate and to the known fitness costs of fat storage. The significant 18% increase in blood oxygen carrying capacity in spring probably helped the birds to meet the additional energy requirements of breeding, particularly the likely increase in flight activity. However, given the magnitude of the increase, other mechanisms must have been involved in meeting breeding costs. The seasonal peak in blood oxygen carrying capacity did not coincide with the time when moulting was most pronounced.

Ecology and Evolution of Blood Oxygen-Carrying Capacity in Birds

2020 ◽  
Vol 195 (5) ◽  
pp. 788-801 ◽  
Author(s):  
Piotr Minias
Keyword(s):  
Carrying Capacity ◽  
Blood Oxygen ◽  
Oxygen Carrying Capacity

scholarly journals Simultaneous exposure to nitrate and low pH reduces the blood oxygen-carrying capacity and functional performance of a freshwater fish

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Daniel F Gomez Isaza ◽  
Rebecca L Cramp ◽  
Craig E Franklin
Keyword(s):  
Carrying Capacity ◽  
Functional Performance ◽  
Swimming Performance ◽  
Low Ph ◽  
Blood Oxygen ◽  
Aerobic Scope ◽  
Simultaneous Exposure ◽  
Post Exercise ◽  
Oxygen Carrying Capacity ◽  
Post Exercise Recovery

Abstract Human activities present aquatic species with numerous of environmental challenges, including excessive nutrient pollution (nitrate) and altered pH regimes (freshwater acidification). In isolation, elevated nitrate and acidic pH can lower the blood oxygen-carrying capacity of aquatic species and cause corresponding declines in key functional performance traits such as growth and locomotor capacity. These factors may pose considerable physiological challenges to organisms but little is known about their combined effects. To characterise the energetic and physiological consequences of simultaneous exposure to nitrate and low pH, we exposed spangled perch (Leiopotherapon unicolor) to a combination of nitrate (0, 50 or 100 mg L−1) and pH (pH 7.0 or 4.0) treatments in a factorial experimental design. Blood oxygen-carrying capacity (haemoglobin concentration, methaemoglobin concentrations and oxygen equilibrium curves), aerobic scope and functional performance traits (growth, swimming performance and post-exercise recovery) were assessed after 28 days of exposure. The oxygen-carrying capacity of fish exposed to elevated nitrate (50 and 100 mg L−1) was compromised due to reductions in haematocrit, functional haemoglobin levels and a 3-fold increase in methaemoglobin concentrations. Oxygen uptake was also impeded due to a right shift in oxygen–haemoglobin binding curves of fish exposed to nitrate and pH 4.0 simultaneously. A reduced blood oxygen-carrying capacity translated to a lowered aerobic scope, and the functional performance of fish (growth and swimming performance and increased post-exercise recovery times) was compromised by the combined effects of nitrate and low pH. These results highlight the impacts on aquatic organisms living in environments threatened by excessive nitrate and acidic pH conditions.

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