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Physiological and Biochemical Zoology: PBZ

Brent Sinclair
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September 2016: Physiological and Biochemical Zoology: PBZ
Barbara Tschirren, Ann-Kathrin Ziegler, Cindy I Canale, Monika Okuliarová, Michal Zeman, Mathieu Giraudeau
Yolk androgens of maternal origin are important mediators of prenatal maternal effects. Although in many species short-term benefits of exposure to high yolk androgen concentrations for the offspring have been observed, females differ substantially in the amount of androgens they transfer to their eggs. It suggests that costs for the offspring or the mother constrain the evolution of maternal hormone transfer. However, to date, the nature of these costs remains poorly understood. Unlike most previous work that focused on potential costs for the offspring, we here investigated whether high yolk testosterone transfer is associated with metabolic costs (i...
September 2016: Physiological and Biochemical Zoology: PBZ
Rémy Simide, Frédéric Angelier, Sandrine Gaillard, Antoine Stier
Telomeres shorten at each cell division due to the end-replication problem but also in response to oxidative stress. Consequently, telomeres shorten with age in many endotherms, and this shortening is accelerated under stressful environmental conditions. Data in ectotherm vertebrates remain scarce so far, so our goal was to review existing data for fish and to test the influence of age and stress on telomere length in a very long-lived fish, the Siberian sturgeon (Acipenser baerii). Our review of the literature revealed age-related telomere shortening in approximately half of the published studies...
September 2016: Physiological and Biochemical Zoology: PBZ
Janek Urvik, Richard Meitern, Kalev Rattiste, Lauri Saks, Peeter Hõrak, Tuul Sepp
Age-related declines in life-history traits have been widely observed in free-living animals. Several theories link senescence to oxidative stress. The aim of this study was to measure several widely used markers of oxidative and nutritional state in a long-lived seabird, the common gull (Larus canus), in order to assess the suitability of these markers for describing deterioration in physiological condition associated with chronological age and survival. Associations with longevity and individual consistency of these parameters over the years (repeatability) were also assessed...
September 2016: Physiological and Biochemical Zoology: PBZ
Rachael M Heuer, Kathleen M Munley, Nafis Narsinghani, Jessica A Wingar, Theresa Mackey, Martin Grosell
Most marine teleosts defend blood pH during high CO2 exposure by sustaining elevated levels of HCO3(-) in body fluids. In contrast to the gill, where measures are taken to achieve net base retention, elevated CO2 leads to base loss in the intestine of marine teleosts studied to date. This loss is thought to occur through transport pathways previously demonstrated to be involved with routine osmoregulation in marine teleosts. The main objective of this study was to characterize the intestinal transport physiology of the gulf toadfish (Opsanus beta) when exposed to varied levels of CO2: control, 5,000, 10,000, and 20,000 μatm CO2 (0...
September 2016: Physiological and Biochemical Zoology: PBZ
Alexa Fritzsche McKay, Vanessa O Ezenwa, Sonia Altizer
Organisms have a finite pool of resources to allocate toward multiple competing needs, such as development, reproduction, and enemy defense. Abundant resources can support investment in multiple traits simultaneously, but limited resources might promote trade-offs between fitness-related traits and immune defenses. We asked how food restriction at both larval and adult life stages of the monarch butterfly (Danaus plexippus) affected measures of immunity, fitness, and immune-fitness interactions. We experimentally infected a subset of monarchs with a specialist protozoan parasite to determine whether parasitism further affected these relationships and whether food restriction influenced the outcome of infection...
September 2016: Physiological and Biochemical Zoology: PBZ
Nicholas W Pilfold, Daryll Hedman, Ian Stirling, Andrew E Derocher, Nicholas J Lunn, Evan Richardson
Polar bears (Ursus maritimus) have adapted to an annual cyclic regime of feeding and fasting, which is extreme in seasonal sea ice regions of the Arctic. As a consequence of climate change, sea ice breakup has become earlier and the duration of the open-water period through which polar bears must rely on fat reserves has increased. To date, there is limited empirical data with which to evaluate the potential energetic capacity of polar bears to withstand longer fasts. We measured the incoming and outgoing mass of inactive polar bears (n = 142) that were temporarily detained by Manitoba Conservation and Water Stewardship during the open-water period near the town of Churchill, Manitoba, Canada, in 2009-2014...
September 2016: Physiological and Biochemical Zoology: PBZ
Alison H Doherty, Danielle M Roteliuk, Sara E Gookin, Ashley K McGrew, Carolyn J Broccardo, Keith W Condon, Jessica E Prenni, Samantha J Wojda, Gregory L Florant, Seth W Donahue
Periods of physical inactivity increase bone resorption and cause bone loss and increased fracture risk. However, hibernating bears, marmots, and woodchucks maintain bone structure and strength, despite being physically inactive for prolonged periods annually. We tested the hypothesis that bone turnover rates would decrease and bone structural and mechanical properties would be preserved in hibernating marmots (Marmota flaviventris). Femurs and tibias were collected from marmots during hibernation and in the summer following hibernation...
September 2016: Physiological and Biochemical Zoology: PBZ
Chris J Law, Colleen Young, Rita S Mehta
Sexual dimorphism attributed to niche divergence is often linked to differentiation between the sexes in both dietary resources and characters related to feeding and resource procurement. Although recent studies have indicated that southern sea otters (Enhydra lutris nereis) exhibit differences in dietary preferences as well as sexual dimorphism in skull size and shape, whether these intersexual differences translate to differentiation in feeding performances between the sexes remains to be investigated. To test the hypothesis that scaling patterns of bite force, a metric of feeding performance, differ between the sexes, we calculated theoretical bite forces for 55 naturally deceased male and female southern sea otters spanning the size ranges encountered over ontogeny...
September 2016: Physiological and Biochemical Zoology: PBZ
Don J Larson, Brian M Barnes
Ice nucleation across the skin of wood frogs (Lithobates sylvaticus) rapidly induces endogenous production of glucose, a cryoprotectant necessary for freeze tolerance. In laboratory studies of freeze tolerance, wood frogs are cooled slowly, often at -0.05°C h(-1), to facilitate high cryoprotectant production and survival. Under natural conditions in Alaska, however, wood frogs accumulate maximal tissue glucose concentrations while cooling at much faster rates, -0.35° to -1.6°C h(-1), and in addition undergo multiple successive freeze-thaw cycles before remaining frozen for the winter...
July 2016: Physiological and Biochemical Zoology: PBZ
A S Pollard, A A Pitsillides, S J Portugal
Avian embryos are a commonly used model system for developmental studies, but monitoring of physiological parameters such as heart rate (HR) and movement in ovo poses a challenge to researchers. These are also increasingly common research objectives for ecological and embryo behavior studies in oviparous species. We therefore explored the validity of a new digital egg-monitoring system for the noninvasive monitoring of these parameters. We tested the relationship between frequency-of-movement values gathered by digital monitoring and those gathered by the current standard method, which is comparatively invasive and requires egg windowing, and demonstrated that the digital monitoring method effectively distinguishes individual movements but cannot reliably monitor HR in actively motile embryos...
July 2016: Physiological and Biochemical Zoology: PBZ
Gareth R Hopkins, Edmund D Brodie, Lorin A Neuman-Lee, Shabnam Mohammadi, George A Brusch, Zoë M Hopkins, Susannah S French
Freshwater organisms are increasingly exposed to elevated salinity in their habitats, presenting physiological challenges to homeostasis. Amphibians are particularly vulnerable to osmotic stress and yet are often subject to high salinity in a variety of inland and coastal environments around the world. Here, we examine the physiological responses to elevated salinity of rough-skinned newts (Taricha granulosa) inhabiting a coastal stream on the Pacific coast of North America and compare the physiological responses to salinity stress of newts living in close proximity to the ocean with those of newts living farther upstream...
July 2016: Physiological and Biochemical Zoology: PBZ
Lucas J Kirschman, Savhannah Haslett, Kelley A Fritz, Matt R Whiles, Robin W Warne
Exposure to environmental stressors alters animal phenotypes as well as nutrient metabolism, assimilation, and excretion. While stress-induced shifts in nutrient processes are known to alter organismal carbon (C) and nitrogen (N) stoichiometry, there has been little exploration of how environmental factors influence phosphorous (P). A better understanding of how P cycling varies with animal physiological state may provide insight into across-scale processes, because P is essential to animal function and ecological processes such as production and decomposition...
July 2016: Physiological and Biochemical Zoology: PBZ
Andrew D McClellan, Timothée Pale, J Alex Messina, Scott Buso, Ahmad Shebib
The spinal locomotor networks controlling swimming behavior in larval and adult lampreys may have some important differences. As an initial step in comparing the locomotor systems in lampreys, in larval animals the relative timing of locomotor movements and muscle burst activity were determined and compared to those previously published for adults. In addition, the kinematics for free swimming in larval and adult lampreys was compared in detail for the first time. First, for swimming in larval animals, the neuromechanical phase lag between the onsets or terminations of muscle burst activity and maximum concave curvature of the body increased with increasing distance along the body, similar to that previously shown in adults...
July 2016: Physiological and Biochemical Zoology: PBZ
Donovan P German, Dolly M Foti, Joseph Heras, Hooree Amerkhanian, Brent L Lockwood
Amylase activity variation in the guts of several model organisms appears to be explained by amylase gene copy number variation. We tested the hypothesis that amylase gene copy number is always elevated in animals with high amylolytic activity. We therefore sequenced the amylase genes and examined amylase gene copy number in prickleback fishes (family Stichaeidae) with different diets including two species of convergently evolved herbivores with the elevated amylase activity phenotype. We found elevated amylase gene copy number (six haploid copies) with sequence variation among copies in one herbivore (Cebidichthys violaceus) and modest gene copy number (two to three haploid copies) with little sequence variation in the remaining taxa, which included herbivores, omnivores, and a carnivore...
July 2016: Physiological and Biochemical Zoology: PBZ
Alice Carravieri, Martina S Müller, Ken Yoda, Shin-Ichi Hayama, Maki Yamamoto
Heart rate (HR) and heart rate variability (HRV) provide noninvasive measures of the relative activity of the parasympathetic nervous system (PNS), which promotes self-maintenance and restoration, and the sympathetic nervous system (SNS), which prepares an animal for danger. The PNS decreases HR, whereas the SNS increases HR. The PNS and SNS also contribute to oscillations in heartbeat intervals at different frequencies, producing HRV. HRV promotes resilience and adjustment capacity in the organism to intrinsic and extrinsic changes...
July 2016: Physiological and Biochemical Zoology: PBZ
Steven J Portugal, Jonathan A Green, Lewis G Halsey, Walter Arnold, Vincent Careau, Peter Dann, Peter B Frappell, David Grémillet, Yves Handrich, Graham R Martin, Thomas Ruf, Magella M Guillemette, Patrick J Butler
Energy management models provide theories and predictions for how animals manage their energy budgets within their energetic constraints, in terms of their resting metabolic rate (RMR) and daily energy expenditure (DEE). Thus, uncovering what associations exist between DEE and RMR is key to testing these models. Accordingly, there is considerable interest in the relationship between DEE and RMR at both inter- and intraspecific levels. Interpretation of the evidence for particular energy management models is enhanced by also considering the energy spent specifically on costly activities (activity energy expenditure [AEE] = DEE - RMR)...
May 2016: Physiological and Biochemical Zoology: PBZ
Lucie Gerber, Carol Eunmi Lee, Evelyse Grousset, Eva Blondeau-Bidet, Nesrine Boudour Boucheker, Catherine Lorin-Nebel, Mireille Charmantier-Daures, Guy Charmantier
The copepod Eurytemora affinis has an unusually broad salinity range, as some populations have recently invaded freshwater habitats independently from their ancestral saline habitats. Prior studies have shown evolutionary shifts in ion transporter activity during freshwater invasions and localization of ion transporters in newly discovered "Crusalis organs" in the swimming legs. The goals of this study were to localize and quantify expression of ion transport enzymes V-type H(+)-ATPase (VHA) and Na(+)/K(+)-ATPase (NKA) in the swimming legs of E...
May 2016: Physiological and Biochemical Zoology: PBZ
W S Marshall, J C Tait, E W Mercer
Mummichogs prefer seawater (SW) but have wide ability to acclimate to extreme temperatures and salinities. In the field, minnow trapping revealed that mummichogs move progressively into low-salinity warmer water during early spring after ice melt and show significant aversion to colder temperatures and high salinity. First appearance in estuarine shallows occurred above 10°C, and catch increased to 21°C over 4 wk. Three-spine sticklebacks (Gasterosteus aculeatus) also preferred warmer low-salinity locations but preferred slowing streams, whereas mummichogs preferred tidal ponds...
May 2016: Physiological and Biochemical Zoology: PBZ
Lidia López-Jiménez, Julio Blas, Alessandro Tanferna, Sonia Cabezas, Tracy Marchant, Fernando Hiraldo, Fabrizio Sergio
We examined whether hypothalamic-pituitary-adrenal axis activity in the nestlings of a semialtricial raptor, the black kite (Milvus migrans), varied with advancing age, throughout the day, and in response to a number of socioecological factors presumed to affect allostatic load. Both baseline corticosterone (CORT) titers and maximum CORT levels during 30 min of handling and restraint augmented across all sampled ages, suggesting that nestlings' energetic demands and capacity to respond to perturbations increase progressively throughout development...
May 2016: Physiological and Biochemical Zoology: PBZ
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