Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

A comparative and ontogenetic examination of mitochondrial function in Antarctic notothenioid species
In this study we examined aerobic metabolic capacity in three species,Trematomus bernacchii,T. pennellii andT. newnesi, and between two life stages, juvenile and adult, by assessing mitochondrial function of permeabilized cardiac fibers. Respiratory capacity differed among the adult notothenioids in this study, with greater oxidative phosphorylation (OXPHOS) respiration in the pelagicT. newnesi than the benthicT. bernacchii andT. pennellii. The variation in mitochondrial respiratory capacity was likely driven by differences in the mitochondrial content, as measured by citrate synthase activity, which was the highest inT. n...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 14, 2022 Category: Physiology Source Type: research

The roles of plasma accessible and cytosolic carbonic anhydrases in bicarbonate (HCO3 −) excretion in Pacific hagfish (Eptatretus stoutii)
AbstractPacific hagfish (Eptatretus stoutii) are marine scavengers and feed on decaying animal carrion by burrowing their bodies inside rotten carcasses where they are exposed to several threatening environmental stressors, including hypercapnia (high partial pressures of CO2). Hagfish possess a remarkable capacity to tolerate hypercapnia, and their ability to recover from acid –base disturbances is well known. To deal with the metabolic acidosis resulting from exposure to high CO2, hagfish can mount a rapid elevation of plasma HCO3− concentration (hypercarbia). OncePCO2 is restored, hagfish quickly excrete their HCO3â...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 13, 2022 Category: Physiology Source Type: research

Nutritional state variations in a tropical seabird throughout its breeding season
This study contributes to a better understanding of seabird breeding ecology and physiology by showing that sex -specific breeding roles might highly influence the nutritional state. Similar patterns might occur in other seabird species, helping to explain why we can find stage- and sex-specific foraging behaviors even in monomorphic species. (Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology)
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 13, 2022 Category: Physiology Source Type: research

Skin ionocyte density of amphibious killifishes is shaped by phenotypic plasticity and constitutive interspecific differences
AbstractWhen amphibious fishes are on land, gill function is reduced or eliminated and the skin is hypothesized to act as a surrogate site of ionoregulation. Skin ionocytes are present in many fishes, particularly those with amphibious life histories. We used nine closely related killifishes spanning a range of amphibiousness to first test the hypothesis that amphibious killifishes have evolved constitutively increased skin ionocyte density to promote ionoregulation on land. We found that skin ionocyte densities were constitutively higher in five of seven amphibious species examined relative to exclusively water-breathing ...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 3, 2022 Category: Physiology Source Type: research

Seasonal immune rhythm of leukocytes in the freshwater snakehead fish, Channa punctatus
This study aims to characterize the seasonal variability in the leukocyte immune responses inChanna punctatus. Leukocytes were harvested from peripheral blood and respiratory burst activity, leukocyte phagocytosis, and nitrite production were assessed to study innate immunity. Peripheral blood lymphocytes were segregated by centrifugation (density gradient) and proliferative responses of lymphocytes, in the presence of mitogens, were used to study cell-mediated immunity. Annual rhythms were validated in superoxide anion production, nitrite release and phagocytosis. Cosinor analysis revealed a differential pattern of lympho...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 2, 2022 Category: Physiology Source Type: research

Short-term responses of Rana arvalis tadpoles to pH and predator stress: adaptive divergence in behavioural and physiological plasticity?
AbstractEnvironmental stress is a major driver of ecological and evolutionary processes in nature. To cope with stress, organisms can adjust through phenotypic plasticity and/or adapt through genetic change. Here, we compared short-term behavioural (activity) and physiological (corticosterone levels, CORT) responses ofRana arvalis tadpoles from two divergent populations (acid origin, AOP, versus neutral origin, NOP) to acid and predator stress. Tadpoles were initially reared in benign conditions at pH 7 and then exposed to a combination of two pH (acid versus neutral) and two predator cue (predator cue versus no predator c...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 1, 2022 Category: Physiology Source Type: research

Avoiding the effects of translocation on the estimates of the metabolic rates across an elevational gradient
In this study, we measured resting metabolic rate (RMR) of three populations of the Mesquite lizard (Sceloporus grammicus, Wiegmann 1828) at their native elevations (i.e., 2600, 3200 and 4100  m). Our results showed that at native elevations, mass specific RMR of lizards from the high elevation population (4100 m) did not differ from the RMR of the other populations (i.e., 2600 and 3200 m), whereas the lizards from the low elevation (2600 m) had lower RMR than those from the intermed iate population. These results differ from a previous study in which the RMR of lizards from the same populations were reported to increa...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - September 1, 2022 Category: Physiology Source Type: research

How the green crab Carcinus maenas copes physiologically with a range of salinities
AbstractTo evaluate the physiological ability to adjust to environmental variations of salinity,Carcinus maenas were maintained in 10, 20, 32 (control), 40, and 50  ppt (13.8 ± 0.6 °C) for 7 days. Closed respirometry systems were used to evaluate oxygen consumption (\({\dot{\text{M}}\text{O}}_{{2}}\)), ammonia excretion (Jamm), urea-N excretion (Jurea-N) and diffusive water fluxes (with3H2O). Ions, osmolality, metabolites, and acid –base status were determined in the hemolymph and seawater, and transepithelial potential (TEP) was measured. At the lowest salinity, there were marked increases in\({\dot{\text{M}}\t...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 30, 2022 Category: Physiology Source Type: research

State dependence of arousal from torpor in brown long-eared bats (Plecotus auritus)
AbstractTo cope with periods of low food availability and unsuitable environmental conditions (e.g., short photoperiod or challenging weather), many heterothermic mammals can readily go into torpor to save energy. However, torpor also entails several potential costs, and quantitative energetics can, therefore, be influenced by the individual state, such as available energy reserves. We studied the thermal energetics of brown long-eared bats (Plecotus auritus) in the northern part of its distributional range, including torpor entry, thermoregulatory ability during torpor and how they responded metabolically to an increasing...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 16, 2022 Category: Physiology Source Type: research

Correction to: Impacts of low salinity exposure and antibiotic application on gut transport activity in the Pacific spiny dogfish, Squalus acanthias suckleyi
(Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology)
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 13, 2022 Category: Physiology Source Type: research

Stratification, sex and ontogenetic effects on the lipid and fatty acid profiles in the blubber of sperm whales from Tasmanian waters
We examined the differential deposition of lipids according to layer, sex and ontogeny in the blubber of 31 adult sperm whales (n = 22 females, 9 males) and two calves that stranded off the Tasmanian coast from 2002 to 2004. Total lipid (TL) content varied widely across the blubber layers of adults (27–77%). Overall, females had higher TL content than males possibly representing higher energy needs due to reproduction. Higher TL content in the middle layer of adults (69%) suggests this layer may act as an energy reserve. Wax esters (WE) dominated the blubber and were highest in the outer layer of adults and calves, l...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 8, 2022 Category: Physiology Source Type: research

Flexible energy-saving strategies in female temperate-zone bats
AbstractTorpor is characterized by an extreme reduction in metabolism and a common energy-saving strategy of heterothermic animals. Torpor is often associated with cold temperatures, but in the last decades, more diverse and flexible forms of torpor have been described. For example, tropical bat species maintain a low metabolism and heart rate at high ambient and body temperatures. We investigated whether bats (Nyctalus noctula) from the cooler temperate European regions also show this form of torpor with metabolic inhibition at high body temperatures, and whether this would be as pronounced in reproductive as in non-repro...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 8, 2022 Category: Physiology Source Type: research

Morphologic and physiologic characteristics of green sea turtle (Chelonia mydas) hatchlings in southeastern Florida, USA
In this study, we report health indices for 297 green sea turtle (Chelonia mydas) hatchlings that emerged from 32 nests deposited on Juno Beach, Florida, USA in June –July, 2017. Results of physical examination, morphometrics, and infectious disease testing (chelonid alphaherpesvirus 5, ChHV5), and blood analyte reference intervals (hematology, plasma protein, glucose) are presented. Carapacial scute abnormalities were observed in 36% (108/297) of all hatchlin gs, including abnormal vertebral (86/297, 29%), lateral (72/297, 24%), and both vertebral and lateral (50/297, 17%) scutes. Hatchlings from nests laid in July, whi...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 7, 2022 Category: Physiology Source Type: research

Mitochondrial oxidative phosphorylation response overrides glucocorticoid-induced stress in a reptile
In conclusion, global mitochondrial functioning has to be considered to better understand the proximal causes of the energy budget under stressful periods. (Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology)
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - August 3, 2022 Category: Physiology Source Type: research

Short-term responses of Rana arvalis tadpoles to pH and predator stress: adaptive divergence in behavioural and physiological plasticity?
AbstractEnvironmental stress is a major driver of ecological and evolutionary processes in nature. To cope with stress, organisms can adjust through phenotypic plasticity and/or adapt through genetic change. Here, we compared short-term behavioural (activity) and physiological (corticosterone levels, CORT) responses ofRana arvalis tadpoles from two divergent populations (acid origin, AOP, versus neutral origin, NOP) to acid and predator stress. Tadpoles were initially reared in benign conditions at pH 7 and then exposed to a combination of two pH (acid versus neutral) and two predator cue (predator cue versus no predator c...
Source: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology - July 20, 2022 Category: Physiology Source Type: research