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The Use of Torpor in Reproductive Female Hemprich’s Long‐Eared Bats (Otonycteris hemprichii)Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract We investigated the patterns of torpor use and body temperature (Tb) in reproductive Hemprich’s long‐eared bats (Otonycteris hemprichii; body mass ∼20 g) in the central Negev Desert highlands. We hypothesized that Tb regulation in female O. hemprichii during reproduction is shaped by a trade‐off between the energy and temperature requirements of embryo and pup growth and the mother’s own need to use torpor and passive rewarming to save energy and water. We predicted that patterns of torpor use change during pregnan...
Source: Physiological and Biochemical Zoology - November 19, 2009 Category: Zoology Tags: article Source Type: journals

Age and Breeding Effort as Sources of Individual Variability in Oxidative Stress Markers in a Bird SpeciesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Oxidative stress is the imbalance between the production of pro‐oxidant substances and the level of antioxidant defenses, which leads to oxidative damage. It has been proposed that senescence is the result of accumulated oxidative damage throughout life. In birds, the sources of individual variability in oxidative stress are still poorly understood. Among these sources, age, as related to senescence, should be particularly relevant. Furthermore, recent findings suggest that breeding effort may also deeply influence suscept...
Source: Physiological and Biochemical Zoology - November 18, 2009 Category: Zoology Tags: article Source Type: journals

Betaines and Dimethylsulfoniopropionate as Major Osmolytes in Cnidaria with Endosymbiotic DinoflagellatesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Most marine invertebrates and algae are osmoconformers whose cells accumulate organic osmolytes that provide half or more of cellular osmotic pressure. These solutes are primarily free amino acids and glycine betaine in most invertebrates and small carbohydrates and dimethylsulfoniopropionate (DMSP) in many algae. Corals with endosymbiotic dinoflagellates (Symbiodinium spp.) have been reported to obtain from the symbionts potential organic osmolytes such as glycerol, amino acids, and DMSP. However, corals and their endosymbi...
Source: Physiological and Biochemical Zoology - November 18, 2009 Category: Zoology Tags: article Source Type: journals

Female Zebra Finches (Taeniopygia guttata) Are Chronically but Not Cumulatively “Anemic” during Repeated Egg Laying in Response to Experimental Nest PredationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we investigated the effect of repeated cycles of egg production in response to experimental nest predation (egg removal) on hematological traits in female zebra finches (Taeniopygia guttata). We predicted that if the negative effect of egg production on hematocrit and hemoglobin concentration was cumulative, with anemia being proportional to reproductive effort, then females laying more clutches, or laying successive clutches without recovery during incubation, would show greater reproductive anemia. In contrast, if females maintain hematocrit and hemoglobin concentration at some minimum functional level ind...
Source: Physiological and Biochemical Zoology - November 13, 2009 Category: Zoology Tags: article Source Type: journals

Adaptation versus Allometry: Population and Body Mass Effects on Hypoxic Metabolism in Fundulus grandisEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Hypoxia has significant effects on organisms, from metabolic reduction to death, and could be an important evolutionary force affecting the variation among populations within a species. To determine intraspecific variation in hypoxic metabolism and the effect of body mass, we examine rates of oxygen consumption ($\dot{\mathrm{M}}\textsc{$o$}_{2}$) at seven oxygen concentrations among seven populations of Fundulus grandis that inhabit a mosaic of habitats with different frequencies and intensities of hypoxia. For $\dot{\mathr...
Source: Physiological and Biochemical Zoology - November 5, 2009 Category: Zoology Tags: article Source Type: journals

Functional Morphology of the Gill in Amazonian Freshwater Stingrays (Chondrichthyes: Potamotrygonidae): Implications for Adaptation to FreshwaterEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract The gill morphologies of six species of potamotrygonid freshwater stingrays from the Amazon basin were investigated using light and electron microscopy. Some unique features were found in the potamotrygonid gill: (1) fingerlike protuberances on the gill filament, (2) an Alcian blue/periodic acid–Schiff–positive histochemical reaction for several cell layers in the gill epithelium (except the basal ones), (3) pavement cells with numerous subapical mucous vesicles, (4) very large mucous cells, and (5) follicular Na+/K+‐A...
Source: Physiological and Biochemical Zoology - October 26, 2009 Category: Zoology Tags: article Source Type: journals

The Stress Response of the Highly Social African Cichlid Neolamprologus pulcherEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study investigates the relationship between social status and circulating plasma cortisol in groups of the cooperatively breeding African cichlid Neolamprologus pulcher. Baseline (resting) levels of cortisol were quantified, as was the cortisol response following an acute stressor. Dominants had the higher cortisol concentrations, and these were not related to their social behavior. Cortisol concentrations correlated (positively) with social behaviors and general activity levels only in subordinate males, arguably the individuals with the least stability in the social group. No status‐dependent differential response...
Source: Physiological and Biochemical Zoology - October 6, 2009 Category: Zoology Tags: article Source Type: journals

Running Behavior and Its Energy Cost in Mice Selectively Bred for High Voluntary Locomotor ActivityEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Locomotion is central to behavior and intrinsic to many fitness‐critical activities (e.g., migration, foraging), and it competes with other life‐history components for energy. However, detailed analyses of how changes in locomotor activity and running behavior affect energy budgets are scarce. We quantified these effects in four replicate lines of house mice that have been selectively bred for high voluntary wheel running (S lines) and in their four nonselected control lines (C lines). We monitored wheel speeds and oxyge...
Source: Physiological and Biochemical Zoology - October 2, 2009 Category: Zoology Tags: article Source Type: journals

Water Supplementation Affects the Behavioral and Physiological Ecology of Gila Monsters (Heloderma suspectum) in the Sonoran DesertEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract In desert species, seasonal peaks in animal activity often correspond with times of higher rainfall. However, the underlying reason for such seasonality can be hard to discern because the rainy season is often associated with shifts in temperature as well as water and food availability. We used a combination of the natural climate pattern of the Sonoran Desert and periodic water supplementation to determine the extent to which water intake influenced both the behavioral ecology and the physiological ecology of a long‐lived...
Source: Physiological and Biochemical Zoology - October 2, 2009 Category: Zoology Tags: article Source Type: journals

Determining Feeding State and Rate of Mass Change in Insectivorous Bats Using Plasma Metabolite AnalysisEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Insectivorous bats regularly experience dramatic and sometimes rapid changes in nutrient stores, yet our ability to study these changes has been limited by available techniques. Plasma metabolite analysis has proven effective for studying individual rates of mass change in birds but has not been validated for other taxa. We tested the effectiveness of plasma metabolite analysis by conducting a study with captive big brown bats (Eptesicus fuscus) and little brown bats (Myotis lucifugus) in the field. In the lab, we varied foo...
Source: Physiological and Biochemical Zoology - October 2, 2009 Category: Zoology Tags: article Technical Comment Source Type: journals

Supplementary Testosterone Inhibits Paternal Care in a Tropically Breeding Sparrow, Zonotrichia capensisEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract In most male birds that exhibit paternal care, elevation in testosterone above the breeding baseline reduces nestling provisioning, which can be detrimental to offspring survival. Mechanisms that may allow some males to avoid this detrimental effect of elevated testosterone include (1) decreased sensitivity to testosterone’s effects on behavior and (2) uncoupling of testosterone secretion from territorial challenges (thus reducing the number of transient elevations in testosterone above the breeding baseline). Both of thes...
Source: Physiological and Biochemical Zoology - October 2, 2009 Category: Zoology Tags: article Source Type: journals

Escaping to the Surface: A Phylogenetically Independent Analysis of Hypoxia‐Induced Respiratory Behaviors in SculpinsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Behavioral responses to progressive hypoxia exposure were assessed in several species of fish from the family Cottidae (sculpins), which are distributed along the near‐shore marine environment and differ in their hypoxia tolerance. The use of aquatic surface respiration (ASR) and aerial emergence as a response to progressive decreases in environmental O2 differed between intertidal and subtidal sculpins. Intertidal sculpins consistently displayed ASR followed by emergence behaviors, while the subtidal species performed the...
Source: Physiological and Biochemical Zoology - October 2, 2009 Category: Zoology Tags: article Source Type: journals

The Role of Size in Synchronous Air Breathing of Hoplosternum littoraleEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study highlights how social interaction can affect air‐breathing behaviors and the importance of considering both behavioral and physiological responses of fish to hypoxia to understand the survival mechanisms they employ. (Source: Physiological and Biochemical Zoology)
Source: Physiological and Biochemical Zoology - October 2, 2009 Category: Zoology Tags: article Source Type: journals

Stress and Parental Care in a Wild Teleost Fish: Insights from Exogenous Supraphysiological Cortisol ImplantsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Male largemouth bass (Micropterus salmoides) provide sole parental care over a 4–6‐wk period to a single brood, fanning the eggs to keep them oxygenated and free of silt and defending the brood until the offspring develop antipredator tactics. During this period, fish are highly active and have few opportunities for feeding, so this activity is energetically costly. To understand some of the consequences of stress during this challenging period, we injected fish with cortisol suspended in coconut oil to experimentally ra...
Source: Physiological and Biochemical Zoology - September 30, 2009 Category: Zoology Tags: article Source Type: journals

Carbon Turnover in Tissues of a Passerine Bird: Allometry, Isotopic Clocks, and Phenotypic Flexibility in Organ SizeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Stable isotopes are an important tool for physiological and behavioral ecologists, although their usefulness depends on a thorough understanding of the dynamics of isotope incorporation into tissue(s) over time. In contrast to hair, claws, and feathers, most animal tissues continuously incorporate carbon (and other elements), and so carbon isotope values may change over time, depending on resource use and tissue‐specific metabolic rates. Here we report the carbon turnover rate for 12 tissues from a passerine bird, the zebr...
Source: Physiological and Biochemical Zoology - September 28, 2009 Category: Zoology Tags: article Source Type: journals

Mechanisms Influencing the Timing and Success of Reproductive Migration in a Capital Breeding Semelparous Fish Species, the Sockeye SalmonEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Two populations of homing sockeye salmon (Oncorhynchus nerka; Adams and Chilko) were intercepted in the marine approaches around the northern and southern ends of Vancouver Island (British Columbia, Canada) en route to a natal river. More than 500 salmon were nonlethally biopsied for blood plasma, gill filament tips, and gross somatic energy (GSE) and were released with either acoustic or radio transmitters. At the time of capture, GSE, body length, and circulating testosterone ([T]) differed between populations, differences...
Source: Physiological and Biochemical Zoology - September 25, 2009 Category: Zoology Tags: article Source Type: journals

Why Does Size Matter? A Test of the Benefits of Female Mate Choice in a Teleost Fish Based on Morphological and Physiological Indicators of Male QualityEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract In female mate choice, a female chooses a reproductive partner based on direct or indirect benefits to the female. While sexual selection theory regarding female mate choice is well developed, there are few mechanistic studies of the process by which females evaluate reproductive partners. Using paternal‐care‐providing smallmouth bass (Micropterus dolomieu) as a model, the purpose of this study was to determine the relationship between female mate choice and the morphological and physiological status of chosen males. Thi...
Source: Physiological and Biochemical Zoology - September 21, 2009 Category: Zoology Tags: article Source Type: journals

Aggressive Behavior and Performance in the Tegu Lizard Tupinambis merianaeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Aggression is an important component of behavior in many animals and may be crucial to providing individuals with a competitive advantage when resources are limited. Although much is known about the effects of catecholamines and hormones on aggression, relatively few studies have examined the effects of physical performance on aggression. Here we use a large, sexually dimorphic teiid lizard to test whether individuals that show high levels of physical performance (bite force) are also more aggressive toward a potential threa...
Source: Physiological and Biochemical Zoology - September 16, 2009 Category: Zoology Tags: article Source Type: journals

Muscle Metabolic Capacities and Plasma Cortisol Levels of the Male Three‐Spine Stickleback Gasterosteus aculeatus: Are There “Femme Fatale” or “Macho Male” Effects?Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract To evaluate whether decreases in muscle metabolic capacities and increases in plasma cortisol explain the effects of neighboring conspecifics on male three‐spine sticklebacks Gasterosteus aculeatus, we housed mature males alone, with a mature female, or with a rival mature male. The neighbors were separated from the focal male by a partition that allowed him to smell, see, and hear his neighbor. In the first experiment, focal males were allowed to reproduce, whereas in the second experiment, no reproduction occurred. Color...
Source: Physiological and Biochemical Zoology - September 16, 2009 Category: Zoology Tags: article Source Type: journals

Jettisoning Ballast or Fuel? Caudal Autotomy and Locomotory Energetics of the Cape Dwarf Gecko Lygodactylus capensis (Gekkonidae)Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We examined the effect of tail loss on locomotory costs in the Cape dwarf gecko Lygodactylus capensis (∼0.9 g) using a novel method for collecting data on small lizards, a method previously used for arthropods. We measured CO2 production during 5–10 min of exhaustive exercise (in response to stimulus) and during a 45‐min recovery period. During exercise, we measured speed (for each meter moved) as well as total distance traveled. Contrary to our expectations, tailless geckos overall expended less effort in escape running, moving both slower and for a shorter distance, compared with when they were intact. Tailless gec...
Source: Physiological and Biochemical Zoology - September 16, 2009 Category: Zoology Tags: article Source Type: journals

Macro‐ and Microgeographic Variation in Metabolism and Hormone Correlates in Big Brown Bats (Eptesicus fuscus)Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract To better understand intraspecific variation in basal metabolic rate (BMR), we examined environmental, physiological, and/or cellular bases for residual variation in BMR in big brown bats, Eptesicus fuscus. We measured BMR and plasma levels of thyroid hormone (T3) and leptin in bats captured in maternity colonies in eastern Massachusetts (MA; northern population) and in Alabama and Georgia (ALGA; southern population) to assess macrogeographic (between‐ or among‐population) and microgeographic (within‐population) variat...
Source: Physiological and Biochemical Zoology - September 16, 2009 Category: Zoology Tags: article Source Type: journals

Countergradient Variation in Temperature Preference in Populations of Killifish Fundulus heteroclitusEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Behavioral thermoregulation can allow ectotherms to buffer the effects of changes in environmental temperature, and thus an organism’s preferred temperature is thought to be under strong selection. However, this contention has seldom been tested. We used common killifish Fundulus heteroclitus from high‐latitude (northern) and low‐latitude (southern) populations to investigate intraspecific variation in thermal preference and its relationship to habitat temperature. We quantified the preferred temperatures of northern a...
Source: Physiological and Biochemical Zoology - September 4, 2009 Category: Zoology Tags: article Source Type: journals

High‐Temperature Tolerance in Anhydrobiotic Tardigrades Is Limited by Glass TransitionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we provide the first evidence of the presence of a glass transition during heating in an anhydrobiotic tardigrade through the use of differential scanning calorimetry. (Source: Physiological and Biochemical Zoology)
Source: Physiological and Biochemical Zoology - September 4, 2009 Category: Zoology Tags: article Source Type: journals

Thermal Acclimation and Regulation of Metabolism in a Reptile (Crocodylus porosus): The Importance of Transcriptional Mechanisms and Membrane CompositionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Energy metabolism is fundamental for animal fitness because it fuels locomotion, growth, and reproduction. Mitochondrial capacities often acclimate to compensate for negative thermodynamic effects. Our aim was to determine the importance of transcriptional regulation and membrane fatty acid composition in modulating oxidative capacities at body temperatures selected in a cold and a warm environment by a reptile (Crocodylus porosus). In the cool environment (mean selected Tb = 21°C), mRNA concentrations of the transcription ...
Source: Physiological and Biochemical Zoology - September 4, 2009 Category: Zoology Tags: article Source Type: journals

Manipulating Testosterone to Assess Links between Behavior, Morphology, and Performance in the Brown Anole Anolis sagreiEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we used surgical castration and replacement of exogenous testosterone in adult male brown anoles (Anolis sagrei) to simultaneously examine the effects of testosterone on a suite of morphological (dewlap area, body size), physiological (immune function), behavioral (dewlap, head bob, and push‐up displays), and performance (stamina, sprint speed, bite force) traits. We show that testosterone increases (or castration reduces) growth rate, dewlap area, and bite force. Treatment effects on bite force may simply reflect underlying treatment differences in growth combined with allometry of bite force. Other trait...
Source: Physiological and Biochemical Zoology - August 12, 2009 Category: Zoology Tags: article Source Type: journals

Blackcap Warblers Maintain Digestive Efficiency by Increasing Digesta Retention Time on the First Day of Migratory StopoverEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We examined migratory blackcaps (Sylvia atricapilla) after they performed a northward flight across the Sahara Desert in spring, and we subjected them to a 5‐d artificial stopover. Body mass (mb) changes over the 5‐d period resembled the typical mass change pattern of blackcaps stopping over naturally, with a small increase on the first day and a subsequent peak in the rate of mb gain on day 2 of the stopover. By day 5 of the stopover, the rate of mb gain had decreased to the point that it was not significantly different from that on day 1, presumably because the digestive tract had been rebuilt by this time. The same ...
Source: Physiological and Biochemical Zoology - August 7, 2009 Category: Zoology Tags: article Source Type: journals

Limited Access to Food and Physiological Trade‐Offs in a Long‐Distance Migrant Shorebird. I. Energy Metabolism, Behavior, and Body‐Mass RegulationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Previous experiments showed reduction of basal metabolic rate (BMR) in birds facing energetic challenges. We alternately exposed two groups of red knots (Calidris canutus) to either 6 h or 22 h of food availability for periods of 22 d. Six h of access to food led to a 6%–10% loss of body mass over the first 8 d, with nearly all of the birds' daily energy expenditures supported by body nutrient stores during the first 2 d. Birds responded by increasing feeding behavior and food intake, but the response was slow. There were ...
Source: Physiological and Biochemical Zoology - August 7, 2009 Category: Zoology Tags: article Source Type: journals

Temporal and Spatial Covariation of Gender and Oxidative Stress in the Galápagos Land Iguana Conolophus subcristatusEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we investigate the interpopulation and intersex variation in oxidative damage and plasma antioxidant capacity in the Galápagos land iguana, Conolophus subcristatus, over a 3‐yr study to evaluate what factors (e.g., season, food availability, reproductive activity) can explain levels and patterns of oxidative damage and of plasma antioxidant capacity. Our results indicate that (1) males showed lower levels of oxidative damage, higher levels of plasma antioxidant capacity, and better body condition than females and (2) significant interactions exist among patterns of oxidative damage across sexes, sampling ...
Source: Physiological and Biochemical Zoology - August 6, 2009 Category: Zoology Tags: article Source Type: journals

Selective Fatty Acid Mobilization from Adipose Tissues of the Pheasant (Phasianus colchicus mongolicus) during Food DeprivationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Avian response to fasting has been examined intensively in penguins (Aptenodytes spp.) adapted to long‐term food deprivation but less in species experiencing shorter fasts. Thus, the selectivity in (i) incorporating different fatty acids (FA) from diet into total lipids of white adipose tissue (WAT) and liver and (ii) mobilizing FA from these tissues was examined in pheasants Phasianus colchicus mongolicus fed or fasted for 4 d. Dietary FA were selectively incorporated into intra‐abdominal and subcutaneous WAT having a s...
Source: Physiological and Biochemical Zoology - August 5, 2009 Category: Zoology Tags: article Source Type: journals

Low Metabolism and Inactive Lifestyle of a Tropical Rain Forest Bird Investigated via Heart‐Rate TelemetryEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Birds in the lowland tropical rain forest are expected to have low energy turnover. Here, we used heart rate telemetry to estimate nighttime resting metabolic rate (RMR), daily energy expenditure (DEE), and locomotor activity of a small, long‐lived tropical rain forest–understory bird, the spotted antbird (Hylophylax naevioides). Heart rate was linearly related to oxygen consumption in respirometry measurements that encompassed 96% of heart rates measured in wild birds. Heart rates in the wild ranged from 260 beats/min a...
Source: Physiological and Biochemical Zoology - August 5, 2009 Category: Zoology Tags: article Source Type: journals

Effects of Measurement Duration on the Determination of Basal Metabolic Rate and Evaporative Water Loss of Small Marsupials: How Long Is Long Enough?Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We examined the time course for measurement of basal metabolic rate (BMR; measured as O2 consumption and CO2 production) and standard evaporative water loss (EWL) for six species of small marsupial to determine the minimum time required to achieve basal/standard values. There was a highly significant effect of measurement duration on measured physiological variables with values for O2 consumption, CO2 production, and EWL decreasing with time for all species. The time required to attain values statistically indistinguishable from minimal differed significantly between species, but in general O2 consumption rate reached basa...
Source: Physiological and Biochemical Zoology - August 4, 2009 Category: Zoology Tags: article Source Type: journals

Limited Access to Food and Physiological Trade‐Offs in a Long‐Distance Migrant Shorebird. II. Constitutive Immune Function and the Acute‐Phase ResponseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study investigates changes in constitutive immune function and the acute‐phase response in shorebirds (red knots) faced with limited access time to food. We separated birds into two experimental groups receiving either 6 h or 22 h of food access and measured constitutive immune function. After 3 wk, we induced an acute‐phase response, and after 1 wk of recovery, we switched the groups to the opposite food treatment and measured constitutive immune function again. We found little effect of food treatment on constitutive immune function, which suggests that even under resource limitation, a baseline level of immune ...
Source: Physiological and Biochemical Zoology - August 3, 2009 Category: Zoology Tags: article Source Type: journals

Wild European Starlings (Sturnus vulgaris) Adjust to Captivity with Sustained Sympathetic Nervous System Drive and a Reduced Fight‐or‐Flight ResponseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we investigated changes to the cardiovascular stress response during the first 10 d of captivity of freshly captured wild European starlings (Sturnus vulgaris). We demonstrated that (1) baseline heart rate (HR) remains elevated for several days following transport into captivity, (2) the normal balance between sympathetic nervous system (SNS) and parasympathetic nervous system regulation of HR is disrupted, with the SNS exerting relatively greater control over baseline HR for the first days of captivity, and (3) the HR response to startle, a mild stressor, becomes significantly reduced compared to that of st...
Source: Physiological and Biochemical Zoology - July 31, 2009 Category: Zoology Tags: article Source Type: journals

What Factors Drive Prolactin and Corticosterone Responses to Stress in a Long‐Lived Bird Species (Snow Petrel Pagodroma nivea)?Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we tested the hypothesis that individuals should modulate their prolactin stress response according to the fitness value of the current reproductive effort relative to the fitness value of future reproduction. Specifically, we examined the influence of breeding status (failed breeders vs. incubating birds) and body condition on prolactin and corticosterone stress responses in a long‐lived species, the snow petrel Pagodroma nivea. When facing stressors, incubating birds had higher prolactin levels than failed breeders. However, we found no effect of body condition on the prolactin stress response. The corti...
Source: Physiological and Biochemical Zoology - July 31, 2009 Category: Zoology Tags: article Source Type: journals

Metabolic Similarity Despite Striking Behavioral Divergence: Aerobic Performance in Low‐ and High‐Density Forms of the Mormon CricketEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Mormon crickets, large flightless katydids from western North America, occur in two forms that differ dramatically in population density and daily movement distances. The low‐density form is small and cryptic and moves (Source: Physiological and Biochemical Zoology)
Source: Physiological and Biochemical Zoology - July 31, 2009 Category: Zoology Tags: article Source Type: journals

Plasticity in the Physiological Energetics of Mongolian Gerbils Is Associated with Diet QualityEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Small mammals usually show physiological and behavioral adaptations to cope with seasonal changes in food quality and availability. To examine the adaptive strategy of small rodents responding to varying dietary quality, we acclimated Mongolian gerbils (Meriones unguiculatus) to a high‐fiber diet (HF: 35.5% neutral detergent fiber [NDF] and 21.4% acid detergent fiber [ADF]) for 4 wk and then a relatively low‐fiber diet (LF: standard rat chow, 12.8% NDF and 4.8% ADF) for another 4 wk. Body mass was stable over the course ...
Source: Physiological and Biochemical Zoology - July 29, 2009 Category: Zoology Tags: article Source Type: journals

Plasma Testosterone Correlates with Morph Type across Breeding Substages in Male White‐Throated SparrowsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract White‐throated sparrows (Zonotrichia albicollis) exhibit a genetic polymorphism that affects plumage and behavior in both sexes. White‐striped morphs are more territorially aggressive, whereas tan‐striped morphs provision nestlings at a higher rate. We investigated testosterone physiology in this species in an effort to understand hormonal mechanisms for the observed differences in aggression and parental care between the morphs. We found a small but significant difference in plasma testosterone between free‐living w...
Source: Physiological and Biochemical Zoology - July 28, 2009 Category: Zoology Tags: article Source Type: journals

Energy Reallocation during and after Periods of Nutritional Stress in Steller Sea Lions: Low‐Quality Diet Reduces Capacity for Physiological AdjustmentsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Two groups of female Steller sea lions (groups H and P) were subjected to periods of energy restriction and subsequent refeeding during winter and summer to determine changes in energy partitioning among principal physiological functions and the potential consequences to their fitness. Both sea lion groups consumed high‐quality fish (herring) before and after the energy restrictions. During restrictions, group H was fed a lower quantity of herring and group P a caloric equivalent of low‐quality fish (pollock). Quantitati...
Source: Physiological and Biochemical Zoology - July 28, 2009 Category: Zoology Tags: article Source Type: journals

Directional Evolution of the Slope of the Metabolic Rate–Temperature Relationship Is Correlated with ClimateEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract The evolution of metabolic rate–temperature (MR‐T) reaction norms is of fundamental importance to physiological ecology. Metabolic cold adaptation (MCA) predicts that populations or species from cooler environments will have either a higher metabolic rate at a common temperature or steeper MR‐T relationships, indicating greater sensitivity of respiratory metabolism to temperature. Support for MCA has been found in some insect species by comparing species or populations differing in latitude. However, the generality of ...
Source: Physiological and Biochemical Zoology - July 22, 2009 Category: Zoology Tags: article Source Type: journals

Mitochondrial Proton Conductance in Skeletal Muscle of a Cold‐Exposed Marsupial, Antechinus flavipes, Is Unlikely to Be Involved in Adaptive Nonshivering Thermogenesis but Displays Increased Sensitivity toward Carbon‐Centered RadicalsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract The organs and molecular mechanisms contributing to adaptive thermogenesis in marsupials are not known because some species apparently lack brown adipose tissue (BAT). The increased oxidative capacity and presence of uncoupling protein 3 (UCP3) in skeletal muscle led to speculations on whether uncoupled respiration sustains endothermy in the cold, as found for BAT. Here, we investigated the role of mitochondrial proton conductance in the small Australian marsupial Antechinus flavipes during cold exposure. Although there was ...
Source: Physiological and Biochemical Zoology - July 17, 2009 Category: Zoology Tags: article Source Type: journals

Hemoglobin Genotype Has Minimal Influence on the Physiological Response of Juvenile Atlantic Cod (Gadus morhua) to Environmental ChallengesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Hemoglobin (Hb) polymorphism in cod is associated with temperature‐related differences in biogeographical distribution, and several authors have suggested that functional characteristics of the various hemoglobin isoforms (HbIs) directly influence phenotypic traits such as growth rate. However, no study has directly examined whether Hb genotype translates into physiological differences at the whole animal level. Thus, we generated a family of juvenile Atlantic cod consisting of all three main Hb genotypes (HbI‐1/1, HbI�...
Source: Physiological and Biochemical Zoology - July 2, 2009 Category: Zoology Tags: article Source Type: journals

Sensible Heat Loss from Muskoxen (Ovibos moschatus) Feeding in Winter: Small Calves Are Not at a Thermal Disadvantage Compared with Adult CowsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Muskoxen (Ovibos moschatus) are large (>200 kg adult body mass) mammalian herbivores that overwinter in the polar regions. Calves are around one‐third the body mass of mature females and may be expected to suffer greater thermal stresses in winter compared with adults because the ratio of surface area to volume (SA:vol) is much greater for calves than for adults. We found that during feeding bouts, when animals are fully exposed to environmental conditions, calves did lose sensible (dry) heat more readily than adults (W m�...
Source: Physiological and Biochemical Zoology - July 1, 2009 Category: Zoology Tags: article Source Type: journals

Circadian and Circannual Rhythms in the Metabolism and Ventilation of Red‐Eared Sliders (Trachemys scripta elegans)Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Endogenous circadian and circannual rhythms may exist in the metabolism, ventilation, and breathing pattern of turtles that could further prolong dive times during daily and seasonal periods of reduced activity. To test this hypothesis, turtles were held under seasonal or constant environmental conditions over a 1‐yr period, and in each season, $\dot{\mathrm{V}}\textsc{$o$}_{2}$ and respiratory variables were measured in all animals under both the prevailing seasonal conditions and the constant conditions for 24 h. Endogen...
Source: Physiological and Biochemical Zoology - June 12, 2009 Category: Zoology Tags: article Source Type: journals

A Mechanistic Model to Study the Thermal Ecology of a Southeastern Pacific Dominant Intertidal Mussel and Implications for Climate ChangeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 82, Issue 4, Page 303-313, July/August 2009. Abstract Developing mechanistic models to predict an organism’s body temperature facilitates the study of physiological stresses caused by extreme climatic conditions the species might have faced in the past or making predictions about changes to come in the near future. Because the models combine empirical observation of different climatic variables with essential morphological attributes of the species, it is possible to examine specific aspects of predicted climatic changes. Here, we develop a model for the competitively d...
Source: Physiological and Biochemical Zoology - May 26, 2009 Category: Zoology Tags: article Articles Source Type: journals

Ontogeny and Individual Variation in the Adrenocortical Response of Zebra Finch (Taeniopygia guttata) NestlingsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 82, Issue 4, Page 325-331, July/August 2009. Abstract Numerous studies indicate interspecies variation in the ontogeny of the adrenocortical response in birds; however, little is known about the extent of interindividual variation in avian young. Toward this end, we examined the ontogeny and interindividual variation in the adrenocortical response in zebra finch (Taeniopygia guttata) nestlings. We measured baseline and stress‐induced total (bound and free) corticosterone, corticosteroid binding globulin capacity, and resulting estimated free corticosterone levels in nes...
Source: Physiological and Biochemical Zoology - May 26, 2009 Category: Zoology Tags: article Articles Source Type: journals

Hydrogen Sulfide Induces Oxidative Damage to RNA and DNA in a Sulfide‐Tolerant Marine InvertebrateEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Hydrogen sulfide acts as an environmental toxin across a range of concentrations and as a cellular signaling molecule at very low concentrations. Despite its toxicity, many animals, including the mudflat polychaete Glycera dibranchiata, are periodically or continuously exposed to sulfide in their environment. We tested the hypothesis that a broad range of ecologically relevant sulfide concentrations induces oxidative stress and oxidative damage to RNA and DNA in G. dibranchiata. Coelomocytes exposed in vitro to sulfide (0–...
Source: Physiological and Biochemical Zoology - March 27, 2009 Category: Zoology Tags: article Source Type: journals

Assessment of Radiolabeled d‐Glucose and the Nonmetabolizable Analog 3‐O‐Methyl‐d‐Glucose as Tools for In Vivo Absorption StudiesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract 3‐O‐methyl‐d‐glucose has been extensively used as a proxy for d‐glucose uptake. This nonmetabolizable analog has lower affinity for transporters, potentially leading to underestimates of glucose absorption rates as well as overestimates of the nutritional significance of passive uptake. Here we sought to precisely quantify the bias, if any, incurred when using 3‐O‐methyl‐d‐glucose by comparing relative absorption rates with d‐glucose in vivo in a seasonally frugivorous bird, the American robin. By simulta...
Source: Physiological and Biochemical Zoology - March 25, 2009 Category: Zoology Tags: article Technical Comment Source Type: journals

Metabolic Alkalosis due to Feeding Chicks in Breeding Adélie Penguins Pygoscelis adeliae under Natural ConditionsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, the concentrations of Cl−, HCO3−, Na+, K+, pH, and $\mathrm{P}\,\textsc{$co$}_{2}$ in the blood of breeding Adélie penguins were measured throughout the chick‐rearing season. The pH of penguin venous blood shifted from 7.54 in the guarding period to 7.47 in the crèche period. Decreasing Cl− and increasing HCO3− blood concentrations in parents were associated with increasing mass of their brood in the guarding period, the early phase of the rearing season, indicating that regurgitating to feed chicks causes loss of gastric acid and results in relative metabolic alkalosis. The inverse trend was obs...
Source: Physiological and Biochemical Zoology - March 20, 2009 Category: Zoology Tags: article Source Type: journals

Ecophysiological Influence on Scaling of Aerobic and Anaerobic Metabolism of Pelagic Gonatid SquidsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We examined the oxygen consumption rates and activity levels of respiratory enzymes involved in the aerobic (citrate synthase [CS]) and anaerobic (octopine dehydrogenase [ODH]) metabolism of gonatid squids (Gonatus onyx and Gonatus pyrus) as a function of body size. The energy expenditure rates of gonatids (ranging from 2.51 to 8.79 μmol O2 g−1 h−1 at 5°C) are among the highest in Animalia when mass and temperature are taken into account. They reflect the low efficiency of jet propulsion and the animals' active life strategy as diel vertical migrants in the pelagic environment. Both metabolic rate and aerobic muscle ...
Source: Physiological and Biochemical Zoology - March 5, 2009 Category: Zoology Tags: article Source Type: journals

A Modified Yolk Biopsy Technique Improves Survivorship of Turtle EggsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we present an improved yolk manipulation technique that resulted in increased egg survival (in excess of 70% survival) in the red‐eared slider turtle (Trachemys scripta) and that may be broadly applicable to other species. By elevating survival to a level on par with other oviparous taxa, this method permits a more thorough exploration of reptilian egg physiology and allows for studies that examine traits in both the egg and the resulting hatchling. (Source: Physiological and Biochemical Zoology)
Source: Physiological and Biochemical Zoology - February 4, 2009 Category: Zoology Tags: article Technical Comment Source Type: journals