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Donald E. Wohlschlag

Bio: Donald E. Wohlschlag is an academic researcher from Marine Science Institute. The author has contributed to research in topics: Acclimatization & Seawater. The author has an hindex of 5, co-authored 6 publications receiving 709 citations.

Papers
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Journal ArticleDOI
07 Mar 1969-Science
TL;DR: Measurements of serum freezing points in three Antarctic marine fishes indicated that they do not freeze in the -1.87�C seawater because their blood is isosmotic to seawater.
Abstract: Measurements of serum freezing points in three Antarctic marine fishes indicated that they do not freeze in the -1.87°C seawater because their blood is isosmotic to seawater. Concentrations of sodium chloride, urea, and free amino acids in the serum accounted for only half of the freezing-point depression of the serum. A protein containing carbohydrate was isolated which accounted for 30 percent of the freezing-point depression of the serum.

597 citations

Journal ArticleDOI
TL;DR: In vitro metabolic levels of tissues of the Antarctic fish Trematomus bernacchii are highly cold-adapted, suggesting that metabolic reorganization can occur during temperature compensation without a concomitant change occuring in the overall metabolic rate.

93 citations

Journal ArticleDOI
TL;DR: The reserve capacity in circulatory ability for oxygen transport through its influence on cardiac output is important in meeting unusual demands of migration or escape, and may prove useful in comparing different species.
Abstract: 1. Injection of phenylhydrazine hydrochloride produced surviving pinfish with as low as 0.26 g.% haemoglobin (2.9% of the normal value). Haematocrits dropped as low as 1-2%, against a normal value of about 30%. 2. Measurements of resting metabolism showed no significant difference related to haemoglobin level, but anaemic fish were slightly higher. 3. Tolerance times at low oxygen levels were not clearly related to haemoglobin levels. 4. Cardiac rates show a compensatory increase in response to haemoglobin reduction which accounts for about 50% of the predicted increase in cardiac output 5. Haemoglobin is thought to provide a reserve capacity in circulatory ability for oxygen transport through its influence on cardiac output. 6. The reserve capacity is important in meeting unusual demands of migration or escape, and may prove useful in comparing different species.

51 citations

Journal ArticleDOI
TL;DR: Responses to hypoxia probably represent ventilatory adjustments which serve to maintain a constant oxygen supply to the gills under conditions of oxygen depletion.
Abstract: Ventilation volume, ventilatory frequency, ventilatory stroke volume, percentage utilization of oxygen and respiratory metabolism were measured on unanaesthetized striped mullet, Mugil cephalus L., under ambient and hypoxic conditions with a modified van Dam respiration chamber. Hypoxia caused a statistically significant increase in ventilation volume, ventilatory frequency, and ventilatory stroke volume and a significant decrease in percentage utilization of oxygen. The routine rate of respiratory metabolism was not significantly altered by hypoxia. These responses probably represent ventilatory adjustments which serve to maintain a constant oxygen supply to the gills under conditions of oxygen depletion.

25 citations

Journal ArticleDOI
TL;DR: An investigation of the seasonal variations in the respiratory metabolism of the Atlantic midshipman, Porichthys porosissimus, indicates that it undergoes seasonal acclimatization, reflecting the euryplastic character of the species.

7 citations


Cited by
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Journal ArticleDOI
TL;DR: Analysis of the data for perciform fish provided no support for metabolic cold adaptation and analysis of covariance indicated that the relationships between resting metabolic rate and temperature for various taxa (orders) showed similar slopes but significantly different mean rates.
Abstract: Summary 1. We examined published studies relating resting oxygen consumption to body mass and temperature in post-larval teleost fish. The resulting database comprised 138 studies of 69 species (representing 28 families and 12 orders) living over a temperature range of c. 40 °C. 2. Resting metabolic rate (Rb; mmol oxygen gas h–1) was related to body mass (M; wet mass, g) by Rb = aMb, where a is a constant and b the scaling exponent. The model was fitted by least squares linear regression after logarithmic transformation of both variables. The mean value of scaling exponent, b, for the 69 individual species was 0·79 (SE 0·11). The general equation for all teleost fish was 1nRb = 0·80(1nM) – 5·43. 3. The relationship between resting oxygen consumption and environmental temperature for a 50-g fish was curvilinear. A typical tropical fish at 30°C requires approximately six times as much oxygen for resting metabolism as does a polar fish at 0°C. This relationship could be fitted by several statistical models, of which the Arrhenius model is probably the most appropriate. The Arrhenius model for the resting metabolism of 69 species of teleost fish, corrected to a standard body mass of 50 g, was 1nRb = 15·7 – 5·02.T–1, where T is absolute temperature (103 × K). 4. The Arrhenius model fitted to all 69 species exhibited a lower thermal sensitivity of resting metabolism (mean Q10 = 1·83 over the range 0–30 °C) than typical within-species acclimation studies (median Q10 = 2·40, n = 14). This suggests that evolutionary adaptation has reduced the overall thermal sensitivity of resting metabolism across species. Analysis of covariance indicated that the relationships between resting metabolic rate and temperature for various taxa (orders) showed similar slopes but significantly different mean rates. 5. Analysis of the data for perciform fish provided no support for metabolic cold adaptation (the hypothesis that polar fish show a resting metabolic rate higher than predicted from the overall rate/temperature relationship established for temperate and tropical species). 6. Taxonomic variation in mean resting metabolic rate showed no relationship to phylogeny, although the robustness of this conclusion is constrained by our limited knowledge of fish evolutionary history.

1,222 citations

Journal ArticleDOI
10 Mar 2014-ACS Nano
TL;DR: Effectively trapping air in surface textures of superhydrophobic surfaces weakens the interaction of the surfaces with liquid water, which enables timely removal of impacting and condensed water droplets before freezing occurs.
Abstract: Undesired ice accumulation leads to severe economic issues and, in some cases, loss of lives. Although research on anti-icing has been carried out for decades, environmentally harmless, economical, and efficient strategies for anti-icing remain to be developed. Recent researches have provided new insights into the icing phenomenon and shed light on some promising bio-inspired anti-icing strategies. The present review critically categorizes and discusses recent developments. Effectively trapping air in surface textures of superhydrophobic surfaces weakens the interaction of the surfaces with liquid water, which enables timely removal of impacting and condensed water droplets before freezing occurs. When ice already forms, ice adhesion can be significantly reduced if liquid is trapped in surface textures as a lubricating layer. As such, ice could be shed off by an action of wind or its gravity. In addition, bio-inspired anti-icing strategies via trapping or introducing other media, such as phase change mate...

715 citations

Journal ArticleDOI
11 Jun 1971-Science
TL;DR: The blood serums of Antarctic fishes freeze at -2�C, which is approximately 1�C below the melting points of their serums, which suggest that this thermal hysteresis results from the adsorption of the glycoprotein molecule onto the surface of ice crystals.
Abstract: The blood serums of Antarctic fishes freeze at -2 degrees C, which is approximately 1 degrees C below the melting points of their serums. This thermal hysteresis is due to the influence of serum glycoproteins. The temperatures of freezing and melting of aqueous solutions of the purified glycoproteins suggest that this thermal hysteresis results from the adsorption of the glycoprotein molecule onto the surface of ice crystals.

536 citations

Journal ArticleDOI
TL;DR: A view of why current theories provide an inadequate mechanistic account of the effects of temperature on aerobic metabolic processes across levels of organization from individual proteins to intact animals is presented.
Abstract: Because of its profound effects on the rates of biological processes such as aerobic metabolism, environmental temperature plays an important role in shaping the distribution and abundance of species. As temperature increases, the rate of metabolism increases and then rapidly declines at higher temperatures – a response that can be described using a thermal performance curve (TPC). Although the shape of the TPC for aerobic metabolism is often attributed to the competing effects of thermodynamics, which can be described using the Arrhenius equation, and the effects of temperature on protein stability, this account represents an over-simplification of the factors acting even at the level of single proteins. In addition, it cannot adequately account for the effects of temperature on complex multistep processes, such as aerobic metabolism, that rely on mechanisms acting across multiple levels of biological organization. The purpose of this review is to explore our current understanding of the factors that shape the TPC for aerobic metabolism in response to acute changes in temperature, and to highlight areas where this understanding is weak or insufficient. Developing a more strongly grounded mechanistic model to account for the shape of the TPC for aerobic metabolism is crucial because these TPCs are the foundation of several recent attempts to predict the responses of species to climate change, including the metabolic theory of ecology and the hypothesis of oxygen and capacity-limited thermal tolerance.

499 citations

Journal ArticleDOI
TL;DR: The remarkable diversity of antifreeze types and their seemingly haphazard phylogenetic distribution suggest that these proteins might have evolved recently in response to sea level glaciation occurring just 1-2 million years ago in the northern hemisphere and 10-30 million years old around Antarctica.
Abstract: ▪ Abstract Marine teleosts at high latitudes can encounter ice-laden seawater that is approximately 1°C colder than the colligative freezing point of their body fluids. They avoid freezing by produ...

479 citations