for Journals by Title or ISSN
for Articles by Keywords
help
Followed Journals
Journal you Follow: 0
 
Sign Up to follow journals, search in your chosen journals and, optionally, receive Email Alerts when new issues of your Followed Journals are published.
Already have an account? Sign In to see the journals you follow.
Journal Cover Conservation Physiology
  [2 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Online) 2051-1434
   Published by Oxford University Press Homepage  [370 journals]
  • Right whale poo: the key to conserving an endangered species'

    • Authors: Birnie-Gauvin K.
      PubDate: 2017-11-15
      DOI: 10.1093/conphys/cox063
      Issue No: Vol. 5, No. 1 (2017)
       
  • Multiple steroid and thyroid hormones detected in baleen from eight whale
           species

    • Authors: Hunt K; Lysiak N, Robbins J, et al.
      Abstract: Recent studies have demonstrated that some hormones are present in baleen powder from bowhead (Balaena mysticetus) and North Atlantic right (Eubalaena glacialis) whales. To test the potential generalizability of this technique for studies of stress and reproduction in large whales, we sought to determine whether all major classes of steroid and thyroid hormones are detectable in baleen, and whether these hormones are detectable in other mysticetes. Powdered baleen samples were recovered from single specimens of North Atlantic right, bowhead, blue (Balaenoptera [B.]musculus), sei (B. borealis), minke (B. acutorostrata), fin (B. physalus), humpback (Megaptera novaeangliae) and gray (Eschrichtius robustus) whales. Hormones were extracted with a methanol vortex method, after which we tested all species with commercial enzyme immunoassays (EIAs, Arbor Assays) for progesterone, testosterone, 17β-estradiol, cortisol, corticosterone, aldosterone, thyroxine and tri-iodothyronine, representing a wide array of steroid and thyroid hormones of interest for whale physiology research. In total, 64 parallelism tests (8 species × 8 hormones) were evaluated to verify good binding affinity of the assay antibodies to hormones in baleen. We also tested assay accuracy, although available sample volume limited this test to progesterone, testosterone and cortisol. All tested hormones were detectable in baleen powder of all species, and all assays passed parallelism and accuracy tests. Although only single individuals were tested, the consistent detectability of all hormones in all species indicates that baleen hormone analysis is likely applicable to a broad range of mysticetes, and that the EIA kits tested here perform well with baleen extract. Quantification of hormones in baleen may be a suitable technique with which to explore questions that have historically been difficult to address in large whales, including pregnancy and inter-calving interval, age of sexual maturation, timing and duration of seasonal reproductive cycles, adrenal physiology and metabolic rate.
      PubDate: 2017-11-09
      DOI: 10.1093/conphys/cox061
      Issue No: Vol. 5, No. 1 (2017)
       
  • Semen collection and ejaculate characteristics of the Leopard Tortoise (
           Stigmochelys pardalis )

    • Authors: Zimmerman D; Mitchell M.
      Abstract: The preservation of spermatozoa is an important tool used in conservation programs to increase the genetic diversity of threatened and endangered species. Although routinely used to manage conservation programs for higher vertebrates, there have been limited attempts to establish reproductive assistance programs for tortoises. The purpose of this study was to develop a model for collecting and characterizing semen in Testudinidae. Semen was collected from 13/16 (81.2%, 95% CI: 62–100) adult male leopard tortoises (Stigmochelys pardalis) via electroejaculation under propofol anesthesia. Semen samples were collected most frequently after the second series of electrostimulations (6/13, 46.1%), with fewer animals producing semen after the first (5/13, 38.5%) or third (2/13, 15.4%) electrostimulations. The average volume of a semen sample in the tortoises was 0.26 ml (standard deviation: 0.16, minimum–maximum: 0.1–0.6), the average spermatozoal concentration was 101.62 × 106/ml, and the average motility at time of collection was 57.3%. A rapid decrease in motility was observed in refrigerated samples over 24 h resulting in a median motility of 0% at 24 h post-collection. The results of this study suggest that electroejaculation is a safe and efficient method for collecting semen from leopard tortoises.
      PubDate: 2017-11-09
      DOI: 10.1093/conphys/cox062
      Issue No: Vol. 5, No. 1 (2017)
       
  • To scale or not to scale: a perspective on describing fish energy
           budgeting

    • Authors: Svendsen M; Christensen E, Steffensen J.
      Abstract: Conventionally, dynamic energy budget (DEB) models operate with animals that have maintenance rates scaling with their body volume, and assimilation rates scaling with body surface area. However, when applying such criteria for the individual in a population level model, the emergent behaviour of the conventional model apparently only reflects juveniles and not adult animals. This paper discusses the relevance of what level assumptions are made on, and the subsequent impact on interpreting the animal (top-down or bottom-up). The alternative DEB model has maintenance scaling with body area, and assimilation with body volume—the opposite of the conventional energy budget animal. Likewise, scaling of organism function to body mass is emphasized to take into account the different challenges organisms face when growing in size. It is emphasized that homoeostasis and its challenges are continuously changing, and cannot be assumed constant. The perspective is finalized by a discussion on perceiving animals as machines, and how it can maybe serve as a lingua franca for physiologists and modellers alike.
      PubDate: 2017-10-25
      DOI: 10.1093/conphys/cox056
      Issue No: Vol. 5, No. 1 (2017)
       
  • Reduced metabolic rate indicates declining viability in seed collections:
           an experimental proof-of-concept

    • Authors: Dalziell E; Tomlinson S.
      Abstract: There is increasing investment globally in seed storage facilities for a wide array of purposes, from food security to biodiversity conservation. Best practice when storing seeds in this manner is to periodically test collections for viability, such that declining viability can be used as a trigger for management actions. Typically, viability testing is time consuming and/or destructive, involving germination testing, cut-testing or a range of potential biochemical indicators. Given that respiration (i.e. metabolic activity) is the basic chemical reaction common to all forms of life, measuring metabolic rate should provide a less-destructive, simple and repeatable correlate of seed viability. We compared the viability of seed collections of known proportions of alive and dead seeds to their metabolic rates, calculated as CO2 production (V̇CO2) measured using flow-through respirometery. To maximize the activity of the seeds and our likelihood of measuring metabolic rates, we imbibed the seeds from 12 species of angiosperms, and measured them using an open system respirometer. Measuring metabolic rate in seeds from diverse evolutionary and ecological backgrounds required us to adopt an allometric approach to account for the effects of seed size upon metabolic rate. After doing so, however, we found significant linear relationships between the known viability of our seed collections and their metabolic rates, but these relationships were unique for each species measured. These data provide substantial support to the prospect that measuring metabolic rates can be used to estimate viability of seeds in storage, however, we advocate the development and adoption of more sensitive respirometry equipment, specifically engineered for this purpose in order to achieve truly non-destructive measurements.
      PubDate: 2017-10-17
      DOI: 10.1093/conphys/cox058
      Issue No: Vol. 5, No. 1 (2017)
       
  • Calcium alleviates decreases in photosynthesis under salt stress by
           enhancing antioxidant metabolism and adjusting solute accumulation in
           Calligonum mongolicum

    • Authors: Xu D; Wang W, Gao T, et al.
      Abstract: Calcium is known to affect photosynthesis under normal conditions and induces tolerance in plants to biotic and abiotic stresses through influencing physiological processes. In this study, physiological processes were investigated in the desert plant Calligonum mongolicum to examine how these processes were induced by calcium treatments to alleviate a decrease in photosynthesis under salt stress. Salinity decreased biomass and photosynthesis, regardless of the salt stress level, but increased superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) activity and decreased malondialdehyde (MDA) content under 4 and 8 g/L NaCl and decreased all enzyme indices under 16 g/l NaCl stress. The plants with 5 and 10 mM added calcium had significantly greater biomass and photosynthesis than plants with the non-calcium application or calcium application with 20 mM at all salinity levels. Calcium-treated plants exhibited increases in photosynthesis and biomass along with higher levels of SOD, POD, CAT, APX, GR and total soluble sugar, and lower levels of MDA and proline. Alleviating the effects of salt stress on photosynthesis depended on the concentration of calcium used. Maximum alleviation of salt stress occurred with 5 and 10 mM calcium application. Our result indicated that calcium could be used in forestation and restoration of C. mongolicum in high saline soil.
      PubDate: 2017-10-13
      DOI: 10.1093/conphys/cox060
      Issue No: Vol. 5, No. 1 (2017)
       
  • Water fleas stand the heat and stay in the city

    • Authors: Sopinka N.
      PubDate: 2017-10-11
      DOI: 10.1093/conphys/cox059
      Issue No: Vol. 5, No. 1 (2017)
       
  • Cadmium bioaccumulates after acute exposure but has no effect on
           locomotion or shelter-seeking behaviour in the invasive green shore crab (
           Carcinus maenas )

    • Authors: Blewett T; Newton D, Flynn S, et al.
      Abstract: Cadmium (Cd2+) is a non-essential metal ubiquitous in the environment due to industrial processes. However, little is known regarding the ability of Cd2+ to impact the behaviour of aquatic animals in receiving environments. Green shore crabs (Carcinus maenas) were exposed to waterborne Cd2+ [control (no Cd2+), low (0.30 μmol/L), medium (3.3 μmol/L) and high (63 μmol/L)], for 24 h, then, crabs were placed in an open field and shelter test to determine potential changes in locomotion and preference for shelter. Tissues (gill, haemolymph, stomatogastric ganglion) were taken for bioaccumulation analysis of Cd2+ and ion content. Behavioural testing was recorded with a motion-tracking software system and showed no impact of Cd2+ on any variable in either of the tests used. All three tissues accumulated Cd2+ in a concentration-dependent manner. Crabs exposed to low Cd2+ showed a small but significant decrease in haemolymph Ca2+, however, this effect was not present at higher Cd2+ exposures. Overall, the results indicate that short-term Cd2+ exposure, and the resulting Cd2+ accumulation, had no effect on locomotor and anxiety-related behaviour of green shore crabs.
      PubDate: 2017-09-28
      DOI: 10.1093/conphys/cox057
      Issue No: Vol. 5, No. 1 (2017)
       
  • Balancing personal maintenance with parental investment in a chick-rearing
           seabird: physiological indicators change with foraging conditions

    • Authors: Storey A; Ryan M, Fitzsimmons M, et al.
      Abstract: Seabird parents use a conservative breeding strategy that favours long-term survival over intensive parental investment, particularly under harsh conditions. Here, we examine whether variation in several physiological indicators reflects the balance between parental investment and survival in common murres (Uria aalge) under a wide range of foraging conditions. Blood samples were taken from adults during mid-chick rearing from 2007 to 2014 and analysed for corticosterone (CORT, stress hormone), beta-hydroxybutyrate (BUTY, lipid metabolism reflecting ongoing mass loss), and haematocrit (reflecting blood oxygen capacity). These measures, plus body mass, were related to three levels of food availability (good, intermediate, and poor years) for capelin, the main forage fish for murres in this colony. Adult body mass and chick-feeding rates were higher in good years than in poor years and heavier murres were more likely to fledge a chick than lighter birds. Contrary to prediction, BUTY levels were higher in good years than in intermediate and poor years. Murres lose body mass just after their chicks hatch and these results for BUTY suggest that mass loss may be delayed in good years. CORT levels were higher in intermediate years than in good or poor years. Higher CORT levels in intermediate years may reflect the necessity of increasing foraging effort, whereas extra effort is not needed in good years and it is unlikely to increase foraging success in poor years. Haematocrit levels were higher in poor years than in good years, a difference that may reflect either their poorer condition or increased diving requirements when food is less available. Our long-term data set provided insight into how decisions about resource allocation under different foraging conditions are relating to physiological indicators, a relationship that is relevant to understanding how seabirds may respond to changes in marine ecosystems as ocean temperatures continue to rise.
      PubDate: 2017-09-26
      DOI: 10.1093/conphys/cox055
      Issue No: Vol. 5, No. 1 (2017)
       
  • Development and testing of a simple field-based intermittent-flow
           respirometry system for riverine fishes

    • Authors: Mochnacz N; Kissinger B, Deslauriers D, et al.
      Abstract: By understanding range-wide intraspecific variation in metabolic rate we can better understand how organisms have adapted to their environment. However, methods to quantify metabolic rate of fishes from remote areas or those that cannot be brought back to the laboratory because of imperilment status are lacking. Consequently, practical and reliable field-based methods are needed. To address this need, we developed a simple yet robust intermittent-flow respirometry system, adapted from a design commonly used in the laboratory that is readily suited for field use. Standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS) estimates were obtained from juvenile lake trout (Salvelinus namaycush) and brook trout (Salvelinus fontinalis) using both field- and laboratory-based systems. Whole-fish SMR, MMR and AS estimates from the field and laboratory methods did not differ from one another (ANCOVA and LMM: all P > 0.05) for either species and were comparable to estimates previously reported. Our field setup is a simpler system than the conventional laboratory-based system that requires less power and equipment to operate, yet still offers users the ability to: (1) acclimate fish to the respirometry chamber; (2) measure oxygen consumption during a shorter period (1 h), which yield metabolic rate estimates comparable to systems that take measurements over longer periods; and (3) take repeated oxygen consumption measurements with manual user-defined flush and measurement phase routines. Developing practical and reliable field respirometry methods, as demonstrated here, is important if we wish to improve our ability to predict how imperiled species will respond to changes in their environment. Such knowledge is critical for informing conservation strategies.
      PubDate: 2017-09-23
      DOI: 10.1093/conphys/cox048
      Issue No: Vol. 5, No. 1 (2017)
       
  • Tools for the ex situ conservation of the threatened species, Cycladenia
           humilis var. jonesii

    • Authors: Pence V; Finke L, Chaiken M.
      Abstract: Ex situ conservation is critical for hedging against the loss of plant diversity. For those species (exceptional species) that cannot be conserved long-term in standard seed banks, alternative methods are required, often involving in vitro culture and cryopreservation, or storage in liquid nitrogen. Cycladenia humilis var. jonesii is a federally threatened perennial native to Utah and Arizona. It is classified as an exceptional species, because it produces few seeds, and, thus, in vitro propagation and cryopreservation were investigated as tools for its propagation and preservation. Shoot-propagating cultures were established from both seedling and wild-collected shoots, but cultures from both sources displayed an extreme form of the physiological disorder, hyperhydricity. This phenotype could be at least partially normalized by the use of vented closures, as well as by using agar, rather than gellan gum, in the medium. The hyperhydric (HH) phenotype had a lower dry weight, more branching, minimal leaf development and more poorly developed vascular tissue than the more normal (MN) phenotype. Only more normalized shoots could be rooted and the resulting plants acclimatized. Both HH and MN shoots also provided shoot tips capable of surviving cryopreservation using the droplet vitrification method. These in vitro and cryopreservation methods provide tools that can be used for propagating plants of C. humilis var. jonesii for research and restoration, as well as for supplying shoot tips for the ex situ conservation of this species. The two distinct phenotypes also provide a useful system for studying factors involved in the HH response of this dryland species in vitro.
      PubDate: 2017-09-23
      DOI: 10.1093/conphys/cox053
      Issue No: Vol. 5, No. 1 (2017)
       
  • No evidence for a link between forest herbicides and offspring sex ratio
           in a migratory songbird using high-throughput molecular sexing

    • Authors: Rivers J; Houtz J, Betts M, et al.
      Abstract: Many species that use or require early-successional forest are of conservation concern, including a number of songbirds that have experienced long-term population declines. In this study, our initial goal was to test whether herbicide application intensity was linked to offspring sex ratio in the White-crowned Sparrow (Zonotrichia leucophrys), a species that requires early-successional forest within forested landscapes. However, a rapid and accurate method using direct PCR to sex a large sample of birds (n > 1000 individuals) was unavailable, so our secondary goal was to develop a new approach for rapidly determine offspring sex. We obtained blood samples from sparrow young during the 2013–2014 breeding seasons in regenerating conifer plantations that were treated with one of four treatments (i.e. light, moderate, and intensive herbicide application, or no-spray control). We then optimized a protocol that used a commercially available, direct PCR kit to amplify sex-specific fragments of the CHD (chromo-helicase-DNA-binding) genes directly from whole blood stored in lysis buffer. Using this approach, we found no evidence that offspring sex ratio was linked to herbicide application intensity or to food availability across herbicide treatments. Our molecular sexing technique was 100% accurate when validated on known-sex adults, and 99.9% of our blood samples amplified successfully after being stored in lysis buffer stored for up to 3 years. The application of direct PCR for sexing birds eliminated the need for DNA extraction and substantially reduced sample processing time, cost, and the opportunity for errors during the extraction step. We conclude that forest herbicide application intensity does not influence sparrow offspring sex ratio in our study system, and that our approach provides a rapid, accurate, and tractable method for sexing birds that can facilitate studies that require processing of a large number of samples.
      PubDate: 2017-09-22
      DOI: 10.1093/conphys/cox054
      Issue No: Vol. 5, No. 1 (2017)
       
  • Qiviut cortisol in muskoxen as a potential tool for informing conservation
           strategies

    • Authors: Di Francesco J; Navarro-Gonzalez N, Wynne-Edwards K, et al.
      Abstract: Muskoxen (Ovibos moschatus) are increasingly subject to multiple new stressors associated with unprecedented climate change and increased anthropogenic activities across much of their range. Hair may provide a measurement of stress hormones (glucocorticoids) over periods of weeks to months. We developed a reliable method to quantify cortisol in the qiviut (wooly undercoat) of muskoxen using liquid chromatography coupled to tandem mass spectrometry. We then applied this technique to determine the natural variability in qiviut cortisol levels among 150 wild muskoxen, and to assess differences between sexes, seasons and years of collection. Qiviut samples were collected from the rump of adult muskoxen by subsistence and sport hunters in seven different locations in Nunavut and the Northwest Territories between 2013 and 2016. Results showed a high inter-individual variability in qiviut cortisol concentrations, with levels ranging from 3.5 to 48.9 pg/mg (median 11.7 pg/mg). Qiviut cortisol levels were significantly higher in males than females, and varied seasonally (summer levels were significantly lower than in fall and winter), and by year (levels significantly increased from 2013 to 2015). These differences may reflect distinct environmental conditions and the diverse stressors experienced, as well as physiological and/or behavioural characteristics. Quantification of qiviut cortisol may serve as a valuable tool for monitoring health and informing conservation and management efforts.
      PubDate: 2017-09-15
      DOI: 10.1093/conphys/cox052
      Issue No: Vol. 5, No. 1 (2017)
       
  • Doctor, Doctor give me the news, I’ve got a bad case of salmon flu

    • Authors: Laubenstein TD.
      PubDate: 2017-09-01
      DOI: 10.1093/conphys/cox051
      Issue No: Vol. 5, No. 1 (2017)
       
  • The influence of water temperature on sockeye salmon heart rate recovery
           following simulated fisheries interactions

    • Authors: Prystay TS; Eliason EJ, Lawrence MJ, et al.
      Abstract: Selective harvest policies have been implemented in North America to enhance the conservation of Pacific salmon (Oncorhynchus spp.) stocks, which has led to an increase in the capture and release of fish by all fishing sectors. Despite the immediate survival benefits, catch-and-release results in capture stress, particularly at high water temperatures, and this can result in delayed post-release mortality minutes to days later. The objective of this study was to evaluate how different water temperatures influenced heart rate disturbance and recovery of wild sockeye salmon (Oncorhynchus nerka) following fisheries interactions (i.e. exhaustive exercise). Heart rate loggers were implanted into Fraser River sockeye salmon prior to simulated catch-and-release events conducted at three water temperatures (16°C, 19°C and 21°C). The fisheries simulation involved chasing logger-implanted fish in tanks for 3 min, followed by a 1 min air exposure. Neither resting nor routine heart rate differed among temperature treatments. In response to the fisheries simulation, peak heart rate increased with temperature (16°C = 91.3 ± 1.3 beats min−1; 19°C = 104.9 ± 2.0 beats min−1 and 21°C = 117 ± 1.3 beats min−1). Factorial heart rate and scope for heart rate were highest at 21°C and lowest at 16°C, but did not differ between 19°C and 21°C. Temperature affected the initial rate of cardiac recovery but not the overall duration (~10 h) such that the rate of energy expenditure during recovery increased with temperature. These findings support the notion that in the face of climate change, efforts to reduce stress at warmer temperatures will be necessary if catch-and-release practices are to be an effective conservation strategy.
      PubDate: 2017-08-22
      DOI: 10.1093/conphys/cox050
      Issue No: Vol. 5, No. 1 (2017)
       
  • Saving California's native fishes: physiological and behavioural
           approaches

    • Authors: Cech JJ; Jr..
      Abstract: Many of California's diverse, freshwater habitats have been modified, limiting the normal movements of many resident and migratory fishes. My students, colleagues and I used physiological and behavioural approaches to study the environmental requirements of native fishes that had low, or steeply declining, population sizes. Findings included swimming muscle ‘remodelling’ and decreases in sustained swimming performance in coho salmon as they developed towards their salt-water life-stage. These results, plus those on juvenile green sturgeon's decreases in swimming performance with salt-water readiness and this species' vulnerability to water diversions, should help natural resource managers set stream and river standards to ensure adequate flows for preserving our natural heritage of native fishes.
      PubDate: 2017-08-17
      DOI: 10.1093/conphys/cox044
      Issue No: Vol. 5, No. 1 (2017)
       
  • Validation, values and vision: ways early career researchers can help
           propel the field of conservation physiology

    • Authors: Madliger CL.
      PubDate: 2017-08-14
      DOI: 10.1093/conphys/cox045
      Issue No: Vol. 5, No. 1 (2017)
       
  • Foraging for fast food: the changing diets of wildlife

    • Authors: Rodgers EM.
      PubDate: 2017-08-09
      DOI: 10.1093/conphys/cox046
      Issue No: Vol. 5, No. 1 (2017)
       
  • How experimental biology and ecology can support evidence-based
           decision-making in conservation: avoiding pitfalls and enabling
           application

    • Authors: Cooke SJ; Birnie-Gauvin K, Lennox RJ, et al.
      Abstract: Policy development and management decisions should be based upon the best available evidence. In recent years, approaches to evidence synthesis, originating in the medical realm (such as systematic reviews), have been applied to conservation to promote evidence-based conservation and environmental management. Systematic reviews involve a critical appraisal of evidence, but studies that lack the necessary rigour (e.g. experimental, technical and analytical aspects) to justify their conclusions are typically excluded from systematic reviews or down-weighted in terms of their influence. One of the strengths of conservation physiology is the reliance on experimental approaches that help to more clearly establish cause-and-effect relationships. Indeed, experimental biology and ecology have much to offer in terms of building the evidence base that is needed to inform policy and management options related to pressing issues such as enacting endangered species recovery plans or evaluating the effectiveness of conservation interventions. Here, we identify a number of pitfalls that can prevent experimental findings from being relevant to conservation or would lead to their exclusion or down-weighting during critical appraisal in a systematic review. We conclude that conservation physiology is well positioned to support evidence-based conservation, provided that experimental designs are robust and that conservation physiologists understand the nuances associated with informing decision-making processes so that they can be more relevant.
      PubDate: 2017-08-09
      DOI: 10.1093/conphys/cox043
      Issue No: Vol. 5, No. 1 (2017)
       
  • Polar bears experience skeletal muscle atrophy in response to food
           deprivation and reduced activity in winter and summer

    • Authors: Whiteman JP; Harlow HJ, Durner GM, et al.
      Abstract: When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April–May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these ‘shore’ bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These ‘ice’ bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt.
      PubDate: 2017-08-09
      DOI: 10.1093/conphys/cox049
      Issue No: Vol. 5, No. 1 (2017)
       
  • Heavy with child' Pregnancy status and stable isotope ratios as
           determined from biopsies of humpback whales

    • Authors: Clark CT; Fleming AH, Calambokidis J, et al.
      PubDate: 2017-08-02
      DOI: 10.1093/conphys/cox047
      Issue No: Vol. 5, No. 1 (2017)
       
  • High tolerance to high-light conditions for the protected species
           Ariocarpus kotschoubeyanus (Cactaceae)

    • Authors: Arroyo-Pérez E; Flores J, González-Salvatierra C, et al.
      Abstract: We determined the seasonal ecophysiological performance under perennial plants and under high solar radiation for adult individuals from the ‘living rock’ cactus Ariocarpus kotschoubeyanus, which occurs equally under nurse plants and in open spaces. We evaluated the effective quantum yield of photosystem II (ΦPSII) and the dissipation of thermal energy [non-photochemical quenching (NPQ)] thorough the year. The maximum apparent electron transport rate (ETRmax) and the saturating photosynthetically active photon flux density for PSII (PFDsat) were also determined from rapid light curves. We found that although the ΦPSII was higher in shaded sites under potential nurse plants than in exposed sites, all values were close to the optimal value of 0.83. The high ΦPSII found for A. kotschoubeyanus plants suggests that they use a great proportion of the absorbed light for photosynthesis, under nurse plants as well as in open spaces. We also found higher NPQ values in exposed sites than in shaded ones but only in Autumn, thus reducing the risk of photoinhibition. In addition, the PFDsat was higher in exposed sites than in shaded ones in Spring, Summer and Autumn, but in Winter there were no differences between treatments. We also found high saturating light levels for ETR (PFDsat higher than 1378 μmol m−2 s−1) in all seasons but in winter for shaded and non-shaded plants. Our findings indicate that A. kotschoubeyanus plants use a great proportion of the light that they absorb for photosynthesis. This high tolerance to high-light conditions could explain why A. kotschoubeyanus do not show preferences for protected sites under nurse plants.
      PubDate: 2017-07-17
      DOI: 10.1093/conphys/cox042
      Issue No: Vol. 5, No. 1 (2017)
       
  • Swimming performance in juvenile shortnose sturgeon ( Acipenser
           brevirostrum ): the influence of time interval and velocity increments on
           critical swimming tests

    • Authors: Downie AT; Kieffer JD.
      Abstract: The most utilized method to measure swimming performance of fishes has been the critical swimming speed (UCrit) test. In this test, the fish is forced to swim against an incrementally increasing flow of water until fatigue. Before the water velocity is increased, the fish swims at the water velocity for a specific, pre-arranged time interval. The magnitude of the velocity increments and the time interval for each swimming period can vary across studies making the comparison between and within species difficult. This issue has been acknowledged in the literature, however, little empirical evidence exists that tests the importance of velocity and time increments on swimming performance in fish. A practical application for fish performance is through the design of fishways that enable fish to bypass anthropogenic structures (e.g. dams) that block migration routes, which is one of the causes of world-wide decline in sturgeon populations. While fishways will improve sturgeon conservation, they need to be specifically designed to accommodate the swimming capabilities specific for sturgeons, and it is possible that current swimming methodologies have under-estimated the swimming performance of sturgeons. The present study assessed the UCrit of shortnose sturgeon using modified UCrit to determine the importance of velocity increment (5 and 10 cm s−1) and time (5, 15 and 30 min) intervals on swimming performance. UCrit was found to be influenced by both time interval and water velocity. UCrit was generally lower in sturgeon when they were swum using 5cm s−1 compared with 10 cm s−1 increments. Velocity increment influences the UCrit more than time interval. Overall, researchers must consider the impacts of using particular swimming criteria when designing their experiments.
      PubDate: 2017-06-30
      DOI: 10.1093/conphys/cox038
      Issue No: Vol. 5, No. 1 (2017)
       
  • Physiological and morphological investigation of Arctic grayling (
           Thymallus arcticus ) gill filaments with high salinity exposure and
           recovery

    • Authors: Blair SD; Matheson D, Goss GG.
      Abstract: Freshwater environments are at risk of increasing salinity due to multiple anthropogenic forces including current oil and gas extraction practices that result in large volumes of hypersaline water. Unintentional releases of hypersaline water into freshwater environments act as an osmoregulatory stressor to many aquatic organisms including native salmonids like the Arctic grayling (Thymallus arcticus). Compared to more euryhaline salmonids, Arctic grayling have a reduced salinity tolerance and develop an elevated interlamellar cell mass (ILCM) in response to salinity exposure (17 ppt). In this study, we described the gill morphology and cell types characterizing the ICLM. Further, we investigated whether Arctic grayling could recover in freshwater following a short-term (<48 h) salinity exposure. Arctic grayling were exposed to 17 ppt saline water for 12, 24 and 48 h. Following the 24 and 48 h salinity exposure, Arctic grayling were returned to freshwater for 24 h to assess their ability to recover from, and reverse, the osmotic disturbances. Physiological serum [Na+], [Cl–] and total osmolality were significantly elevated and progressively increased at 12, 24 and 48 h salinity exposures. The 24 h post-exposure recovery period resulted in Arctic grayling serum ion concentrations and total osmolality returning to near normal levels. Similar recovery patterns were observed in the salinity-induced ILCM, which developed as early as 12 h of exposure to 17 ppt, and then reverted to control levels following 24 h in freshwater. Gill histology indicates an increased number of apically located mucous cells in the interlamellar space following salinity exposure of Arctic grayling. The scanning electron microscopy and transmission electron microscopy data show the presence of granule containing eosinophil-like cells infiltrating the ILCM suggesting a salinity-induced immune response by the Arctic grayling.
      PubDate: 2017-06-28
      DOI: 10.1093/conphys/cox040
      Issue No: Vol. 5, No. 1 (2017)
       
  • Forest disturbance leaves some bats stressed and under the weather

    • Authors: Madliger CL.
      PubDate: 2017-06-27
      DOI: 10.1093/conphys/cox041
      Issue No: Vol. 5, No. 1 (2017)
       
  • Assessment of season-dependent body condition scores in relation to faecal
           glucocorticoid metabolites in free-ranging Asian elephants

    • Authors: Pokharel S; Seshagiri PB, Sukumar R.
      Abstract: We studied seasonal and annual changes in visual body condition scores (BCSs), and assessed how these scores were related to levels of faecal glucocorticoid metabolites (fGCMs) in free-ranging Asian elephants (Elephas maximus) in the seasonally dry tropical forests of the Mysore and Nilgiri Elephant Reserves in southern India. We assessed the animals’ BCS visually on a scale of 1 to 5; where 1 represents a very thin and 5 represents a very fat elephant. To understand the influence of seasonality on BCS, we sampled the population during dry (n = 398) and wet seasons (n = 255) of 2013 and 2015 while, for annual changes in BCS, we sampled nine free-ranging adult females from different family groups that had been repeatedly sighted over seven years. To evaluate the influence of body condition on fGCM, 307 faecal samples were collected from 261 different elephants and were analysed. As a parameter of adrenocortical activity, and thus stress, fGCM was measured (μg/g) in the ethanol-extracted samples using a group-specific 11-oxoaetiocholanolone EIA (antibody raised against 11-oxoaetiocholanolone-17-CMO:BSA and biotinylated-11-oxoaetiocholanolone as a label). Effect of age and season on BCS in relation to fGCM was also studied. A seasonal shift in BCS was observed as expected, i.e. individuals with low BCS were more frequent during the dry season when compared with the wet season. Concentrations of fGCM were highest in individuals with lowest BCS (BCS 1) and then significantly declined till BCS 3. fGCM levels were almost comparable for BCS 3, 4 and 5. This pattern was more conspicuous in female than in male elephants. Season-dependent BCS, hence, reflect the stress status as measured by fGCM, especially in female Asian elephants. This could be used as an important non-invasive approach to monitor the physiological health of free-ranging elephant populations.
      PubDate: 2017-06-27
      DOI: 10.1093/conphys/cox039
      Issue No: Vol. 5, No. 1 (2017)
       
  • Molecular indices of viral disease development in wild migrating salmon
           †

    • Authors: Miller KM; Günther OP, Li S, et al.
      Abstract: Infectious diseases can impact the physiological performance of individuals, including their mobility, visual acuity, behavior and tolerance and ability to effectively respond to additional stressors. These physiological effects can influence competitiveness, social hierarchy, habitat usage, migratory behavior and risk to predation, and in some circumstances, viability of populations. While there are multiple means of detecting infectious agents (microscopy, culture, molecular assays), the detection of infectious diseases in wild populations in circumstances where mortality is not observable can be difficult. Moreover, if infection-related physiological compromise leaves individuals vulnerable to predation, it may be rare to observe wildlife in a late stage of disease. Diagnostic technologies designed to diagnose cause of death are not always sensitive enough to detect early stages of disease development in live-sampled organisms. Sensitive technologies that can differentiate agent carrier states from active disease states are required to demonstrate impacts of infectious diseases in wild populations. We present the discovery and validation of salmon host transcriptional biomarkers capable of distinguishing fish in an active viral disease state [viral disease development (VDD)] from those carrying a latent viral infection, and viral versus bacterial disease states. Biomarker discovery was conducted through meta-analysis of published and in-house microarray data, and validation performed on independent datasets including disease challenge studies and farmed salmon diagnosed with various viral, bacterial and parasitic diseases. We demonstrate that the VDD biomarker panel is predictive of disease development across RNA-viral species, salmon species and salmon tissues, and can recognize a viral disease state in wild-migrating salmon. Moreover, we show that there is considerable overlap in the biomarkers resolved in our study in salmon with those based on similar human viral influenza research, suggesting a highly conserved suite of host genes associated with viral disease that may be applicable across a broad range of vertebrate taxa.
      PubDate: 2017-06-27
      DOI: 10.1093/conphys/cox036
      Issue No: Vol. 5, No. 1 (2017)
       
  • Coupling gene-based and classic veterinary diagnostics improves
           interpretation of health and immune function in the Agassiz’s desert
           tortoise ( Gopherus agassizii )

    • Authors: Drake K; Bowen L, Lewison RL, et al.
      Abstract: The analysis of blood constituents is a widely used tool to aid in monitoring of animal health and disease. However, classic blood diagnostics (i.e. hematologic and plasma biochemical values) often do not provide sufficient information to determine the state of an animal’s health. Field studies on wild tortoises and other reptiles have had limited success in drawing significant inferences between blood diagnostics and physiological and immunological condition. However, recent research using gene transcription profiling in the threatened Mojave desert tortoise (Gopherus agassizii) has proved useful in identifying immune or physiologic responses and overall health. To improve our understanding of health and immune function in tortoises, we evaluated both standard blood diagnostic (body condition, hematologic, plasma biochemistry values, trace elements, plasma proteins, vitamin A levels) and gene transcription profiles in 21 adult tortoises (11 clinically abnormal; 10 clinically normal) from Clark County, NV, USA. Necropsy and histology evaluations from clinically abnormal tortoises revealed multiple physiological complications, with moderate to severe rhinitis or pneumonia being the primary cause of morbidity in all but one of the examined animals. Clinically abnormal tortoises had increased transcription for four genes (SOD, MyD88, CL and Lep), increased lymphocyte production, biochemical enzymes and organics, trace elements of copper, and decreased numbers of leukocytes. We found significant positive correlations between increased transcription for SOD and increased trace elements for copper, as well as genes MyD88 and Lep with increased inflammation and microbial insults. Improved methods for health assessments are an important element of monitoring tortoise population recovery and can support the development of more robust diagnostic measures for ill animals, or individuals directly impacted by disturbance.
      PubDate: 2017-06-16
      DOI: 10.1093/conphys/cox037
      Issue No: Vol. 5, No. 1 (2017)
       
  • Matchmaker.com for pandas

    • Authors: Allan BM.
      PubDate: 2017-06-13
      DOI: 10.1093/conphys/cox033
      Issue No: Vol. 5, No. 1 (2017)
       
  • Reflex impairment and physiology as predictors of delayed mortality in
           recreationally caught yellowtail snapper ( Ocyurus chrysurus )

    • Authors: Forrestal FC; McDonald M, Burress G, et al.
      Abstract: Yellowtail snapper (Ocyurus chrysurus) is an important part of the reef fish assemblage in the western, tropical Atlantic and is caught by both recreational and commercial fisheries in south Florida and the Bahamas. It is estimated that 80% of snapper caught within southeastern Florida waters are discarded due to minimum size restrictions. Neglecting to include information on delayed mortality of undersized fish has the potential for fishery managers to overestimate the abundance of smaller size classes and introduce bias into stock assessments. This study examines associations between reflex impairment, traditional physiological parameters and post-release mortality of undersized yellowtail snapper. Laboratory experiments exposed yellowtail snapper to a gradient, simulating capture conditions. Blood draws were obtained from a sub-sample of fish. There was a significant relationship between delayed mortality and the proportion of reflex impairment for both individual fish and groups of fish (P < 0.001 and P = 0.03). Within the sub-sample of blood-sampled fish, base excess and pH were significantly correlated to reflex impairment. Delayed mortality was significantly correlated to pH, base excess and lactate concentration. Results suggest that discarded, undersized yellowtail with more than 29% of their reflexes impaired will not survive.
      PubDate: 2017-06-08
      DOI: 10.1093/conphys/cox035
      Issue No: Vol. 5, No. 1 (2017)
       
  • The quantification of reproductive hormones in the hair of captive adult
           brown bears and their application as indicators of sex and reproductive
           state

    • Authors: Cattet M; Stenhouse GB, Janz DM, et al.
      Abstract: Recognizing the potential value of steroid hormone measurements to augment non-invasive genetic sampling, we developed procedures based on enzyme-linked immunoassays to quantify reproductive steroid hormone concentrations in brown bear (Ursus arctos) hair. Then, using 94 hair samples collected from eight captive adult bears over a 2-year period, we evaluated (i) associations between hair concentrations of testosterone, progesterone, estradiol and cortisol; (ii) the effect of collecting by shaving vs. plucking; and (iii) the utility of reproductive hormone profiles to differentiate sex and reproductive state. Sample requirements (125 mg of guard hair) to assay all hormones exceeded amounts typically obtained by non-invasive sampling. Thus, broad application of this approach will require modification of non-invasive techniques to collect larger samples, use of mixed (guard and undercoat) hair samples and/or application of more sensitive laboratory procedures. Concentrations of hormones were highly correlated suggesting their sequestration in hair reflects underlying physiological processes. Marked changes in hair hormone levels during the quiescent phase of the hair cycle, coupled with the finding that progesterone concentrations, and their association with testosterone levels, differed markedly between plucked and shaved hair samples, suggests steroids sequestered in hair were likely derived from various sources, including skin. Changes in hair hormone concentrations over time, and in conjunction with key reproductive events, were similar to what has been reported concerning hormonal changes in the blood serum of brown bears. Thus, potential for the measurement of hair reproductive hormone levels to augment non-invasive genetic sampling appears compelling. Nonetheless, we are conducting additional validation studies on hair collected from free-ranging bears, representative of all sex, age and reproductive classes, to fully evaluate the utility of this approach for brown bear conservation and research.
      PubDate: 2017-06-01
      DOI: 10.1093/conphys/cox032
      Issue No: Vol. 5, No. 1 (2017)
       
  • Use of physiological knowledge to control the invasive sea lamprey (
           Petromyzon marinus ) in the Laurentian Great Lakes

    • Authors: Siefkes MJ.
      Abstract: Sea lamprey (Petromyzon marinus) control in the Laurentian Great Lakes of North America is an example of using physiological knowledge to successfully control an invasive species and rehabilitate an ecosystem and valuable fishery. The parasitic sea lamprey contributed to the devastating collapse of native fish communities after invading the Great Lakes during the 1800s and early 1900s. Economic tragedy ensued with the loss of the fishery and severe impacts to property values and tourism resulting from sea lamprey-induced ecological changes. To control the sea lamprey and rehabilitate the once vibrant Great Lakes ecosystem and economy, the Great Lakes Fishery Commission (Commission) was formed by treaty between Canada and the United States in 1955. The Commission has developed a sea lamprey control programme based on their physiological vulnerabilities, which includes (i) the application of selective pesticides (lampricides), which successfully kill sedentary sea lamprey larvae in their natal streams; (ii) barriers to spawning migrations and associated traps to prevent infestations of upstream habitats and remove adult sea lamprey before they reproduce; and (iii) the release of sterilized males to reduce the reproductive potential of spawning populations in select streams. Since 1958, the application of the sea lamprey control programme has suppressed sea lamprey populations by ~90% from peak abundance. Great Lakes fish populations have rebounded and the economy is now thriving. In hopes of further enhancing the efficacy and selectivity of the sea lamprey control programme, the Commission is exploring the use of (i) sea lamprey chemosensory cues (pheromones and alarm cues) to manipulate behaviours and physiologies, and (ii) genetics to identify and manipulate genes associated with key physiological functions, for control purposes. Overall, the Commission capitalizes on the unique physiology of the sea lamprey and strives to develop a diverse integrated programme to successfully control a once devastating invasive species.
      PubDate: 2017-05-30
      DOI: 10.1093/conphys/cox031
      Issue No: Vol. 5, No. 1 (2017)
       
  • Substrate roughening improves swimming performance in two small-bodied
           riverine fishes: implications for culvert remediation and design

    • Authors: Rodgers EM; Heaslip BM, Cramp RL, et al.
      Abstract: Worldwide declines in riverine fish abundance and diversity have been linked to the fragmentation of aquatic habitats through the installation of instream structures (e.g. culverts, dams, weirs and barrages). Restoring riverine connectivity can be achieved by remediating structures impeding fish movements by, for example, replacing smooth substrates of pipe culverts with naturalistic substrates (i.e. river stones; culvert roughening). However, empirical evaluations of the efficacy of such remediation efforts are often lacking despite the high economic cost. We assessed the effectiveness of substrate roughening in improving fish swimming performance and linked this to estimates of upstream passage success. Critical swimming speeds (Ucrit) of two small-bodied fish, purple-spotted gudgeon (Mogurnda adspersa; 7.7–11.6 cm total length, BL) and crimson-spotted rainbowfish (Melanotaenia duboulayi; 4.2–8.7 cm BL) were examined. Swimming trials were conducted in a hydraulic flume fitted with either a smooth acrylic substrate (control) or a rough substrate with fixed river stones. Swimming performance was improved on the rough compared to the smooth substrate, with Mo. adspersa (Ucrit-smooth = 0.28 ± 0.0 m s−1, 2.89 ± 0.1 BL s−1, Ucrit-rough = 0.36 ± 0.02 m s−1, 3.66 ± 0.22 BL s−1, mean ± s.e) and Me. duboulayi (Ucrit-smooth = 0.46 ± 0.01 m s−1, 7.79 ± 0.33 BL s−1; Ucrit-rough = = 0.55 ± 0.03 m s−1, 9.83 ± 0.67 BL s−1, mean ± s.e.) both experiencing a 26% increase in relative Ucrit. Traversable water velocity models predicted maximum water speeds allowing successful upstream passage of both species to substantially increase following roughening remediation. Together these findings suggest culvert roughening may be a solution which allows hydraulic efficiency goals to be met, without compromising fish passage.
      PubDate: 2017-05-26
      DOI: 10.1093/conphys/cox034
      Issue No: Vol. 5, No. 1 (2017)
       
  • Nutritional physiology and ecology of wildlife in a changing world

    • Authors: Birnie-Gauvin K; Peiman KS, Raubenheimer D, et al.
      Abstract: Over the last century, humans have modified landscapes, generated pollution and provided opportunities for exotic species to invade areas where they did not evolve. In addition, humans now interact with animals in a growing number of ways (e.g. ecotourism). As a result, the quality (i.e. nutrient composition) and quantity (i.e. food abundance) of dietary items consumed by wildlife have, in many cases, changed. We present representative examples of the extent to which vertebrate foraging behaviour, food availability (quantity and quality) and digestive physiology have been modified due to human-induced environmental changes and human activities. We find that these effects can be quite extensive, especially as a result of pollution and human-provisioned food sources (despite good intentions). We also discuss the role of nutrition in conservation practices, from the perspective of both in situ and ex situ conservation. Though we find that the changes in the nutritional ecology and physiology of wildlife due to human alterations are typically negative and largely involve impacts on foraging behaviour and food availability, the extent to which these will affect the fitness of organisms and result in evolutionary changes is not clearly understood, and requires further investigation.
      PubDate: 2017-05-22
      DOI: 10.1093/conphys/cox030
      Issue No: Vol. 5, No. 1 (2017)
       
  • Blood gases, biochemistry and haematology of Galápagos hawksbill turtles
           ( Eretmochelys imbricata )

    • Authors: Muñoz-Pérez J; Lewbart GA, Hirschfeld M, et al.
      Abstract: The hawksbill turtle, Eretmochelys imbricata, is a marine chelonian with a circum-global distribution, but the species is critically endangered and has nearly vanished from the eastern Pacific. Although reference blood parameter intervals have been published for many chelonian species and populations, including nesting Atlantic hawksbills, no such baseline biochemical and blood gas values have been reported for wild Pacific hawksbill turtles. Blood samples were drawn from eight hawksbill turtles captured in near shore foraging locations within the Galápagos archipelago over a period of four sequential years; three of these turtles were recaptured and sampled on multiple occasions. Of the eight sea turtles sampled, five were immature and of unknown sex, and the other three were females. A portable blood analyzer was used to obtain near immediate field results for a suite of blood gas and chemistry parameters. Values affected by temperature were corrected in two ways: (i) with standard formulas and (ii) with auto-corrections made by the portable analyzer. A bench top blood chemistry analyzer was used to measure a series of biochemistry parameters from plasma. Standard laboratory haematology techniques were employed for red and white blood cell counts and to determine haematocrit manually, which was compared to the haematocrit values generated by the portable analyzer. The values reported in this study provide reference data that may be useful in comparisons among populations and in detecting changes in health status among Galápagos sea turtles. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease or environmental disasters.
      PubDate: 2017-05-10
      DOI: 10.1093/conphys/cox028
      Issue No: Vol. 5, No. 1 (2017)
       
  • Thermotolerance capacities of native and exotic coastal plants will lead
           to changes in species composition under increased heat waves

    • Authors: French K; Robinson SA, Lia J.
      Abstract: With an increase in the frequency and intensity of extreme heat events, plants are likely to reach their thermal limits and show slower growth or increased mortality. We investigated differences amongst coastal native and invasive shrubs and grasses to investigate if particular species might be more at risk in the future. Using an ecologically relevant experimental set of heat waves over a month, we assessed changes in biomass and photosynthetic efficiency in a laboratory setting using 25 coastal Australian species divided into native and exotic shrubs, and native and exotic grasses. We also compared three C3 and three C4 grasses within the native and exotic groups. Overall, native shrubs suffered higher mortality, lower growth and increased photosynthetic stress. There was some evidence that C3 grasses, had lower growth with heat waves, compared to C4 species although, in general, grasses showed evidence of photosynthetic acclimation over the month. Increases in leaf abscission suggest that part of the acclimation process was to develop new, thermally tolerant leaves. Our results indicate that in the future we would expect an increase in exotic shrubs and grasses occupying spaces in coastal plant communities that arise from native mortality following extreme heat events. Management of these coastal communities will need to focus strongly on maintaining a diverse native shrub composition that can resist climate-based disturbances (such as wildfire), as well as controlling the extent and biomass of exotic species, if coastal communities are to remain healthy and diverse in a changing climate.
      PubDate: 2017-05-05
      DOI: 10.1093/conphys/cox029
      Issue No: Vol. 5, No. 1 (2017)
       
  • Comparative swimming and station-holding ability of the threatened Rocky
           Mountain Sculpin ( Cottus sp.) from four hydrologically distinct rivers

    • Authors: Veillard MF; Ruppert JW, Tierney K, et al.
      Abstract: Hydrologic alterations, such as dams, culverts or diversions, can introduce new selection pressures on freshwater fishes, where they are required to adapt to novel environmental conditions. Our study investigated how species adapt to natural and altered stream flow, where we use the threatened Rocky Mountain Sculpin (Cottus sp.) as a model organism. We compared the swimming and station-holding performance of Rocky Mountain Sculpin from four different hydrologic regimes in Alberta and British Columbia, including the North Milk River, a system that experiences increased flows from a large-scale diversion. We measured the slip (Uslip) and failure (Uburst) velocities over three constant acceleration test trials. Uslip was defined as the point at which individuals required the addition of bursting or swimming to maintain position. Uburst was defined as the point at which individuals were unable to hold position in the swimming chamber through swimming, bursting or holding techniques without fully or partially resting on the electrified back plate. We found individuals from the Flathead River in British Columbia (with the highest natural flow) failed at significantly higher Uburst velocities than fish from the southern Albertan populations. However, there was no relationship between peak hydrologic flow from the natal river and Uburst or Uslip. Further, Uburst velocities decreased from 51.8 cm s−1 (7.2 BL s−1) to 45.6 cm s−1 (6.3 BL s−1) by the third consecutive test suggesting the use of anaerobic metabolism. Uslip was not different between trials suggesting the use of aerobic metabolism in station-holding behaviours (Uslip). Moreover, we found no significant differences in individuals from the altered North Milk River system. Finally, individual caudal morphological characteristics were related to both slip and failure velocities. Our study contributes to the conservation of Rocky Mountain Sculpin by providing the first documentation of swimming and station-holding abilities of this benthic fish.
      PubDate: 2017-05-04
      DOI: 10.1093/conphys/cox026
      Issue No: Vol. 5, No. 1 (2017)
       
  • Effect of short-term regulated temperature variations on the swimming
           economy of Atlantic salmon smolts

    • Authors: Alexandre CM; Palstra AP.
      Abstract: Migratory species travelling long distances between habitats to spawn or feed are well adapted to optimize their swimming economy. However, human activities, such as river regulation, represent potential threats to fish migration by changing environmental parameters that will have impact on their metabolism. The main objective of this study was to evaluate the changes in the swimming energetics of a salmonid species, Atlantic salmon (Salmo salar L.), caused by short-term temperature variations that usually result from the operation of hydroelectrical dams. Intermittent flow respirometry in swim tunnels allows to obtain high resolution data on oxygen consumption of swimming fish which can reflect aerobic and anaerobic metabolism. This method was used to compare the metabolic rates of oxygen consumption before, during and after sudden thermal change. Control (no temperature variation) and experimental (temperature variation of approximately 4°C in 1 h) swimming trials were conducted to achieve the following objectives: (i) quantify the variations in oxygen consumption associated with abrupt temperature decrease, and (ii) assess if the tested fish return quickly to initial oxygen consumption rates. Main results revealed that Atlantic salmon smolts show a strong response to sudden temperature variation, significantly reducing the oxygen consumption rate up to a seven-fold change. Fish quickly returned to initial swimming costs shortly after reestablishment of temperature values. Results from this study can be used to evaluate the species-specific effects of the applied operation modes by hydroelectrical dams and to increase the success of conservation and management actions directed to fish species inhabiting regulated rivers.
      PubDate: 2017-05-04
      DOI: 10.1093/conphys/cox025
      Issue No: Vol. 5, No. 1 (2017)
       
  • Chill out: physiological responses to winter ice-angling in two temperate
           freshwater fishes

    • Authors: Louison MJ; Hasler CT, Raby GD, et al.
      Abstract: A large body of research has documented the stress response of fish following angling capture. Nearly all of these studies have taken place during the open-water season, with almost no work focused on the effects of capture in the winter via ice angling. We therefore conducted a study to examine physiological disturbance and reflex impairment following capture by ice-angling in two commonly targeted species, bluegill Lepomis macrochirus and yellow perch Perca flavescens. Fish were captured from a lake in eastern Wisconsin (USA) and sampled either immediately or after being held in tanks for 0.5, 2 or 4 h. Sampling involved the assessment of reflex action mortality predictors (RAMP) and a blood biopsy that was used to measure concentrations of plasma cortisol and lactate. The capture-induced increase in plasma cortisol concentration was delayed relative to responses documented in previous experiments conducted in the summer and reached a relative high point at 4 h post-capture. Reflex impairment was highest at the first post-capture time point (0.5 h) and declined with each successive sampling (2 and 4 h) during recovery. Bluegill showed a higher magnitude stress response than yellow perch in terms of plasma cortisol and RAMP scores, but not when comparing plasma lactate. Overall, these data show that ice-angling induces a comparatively mild stress response relative to that found in previous studies of angled fish. While recovery of plasma stress indicators does not occur within 4 h, declining RAMP scores demonstrate that ice-angled bluegill and yellow perch do recover vitality following capture.
      PubDate: 2017-04-27
      DOI: 10.1093/conphys/cox027
      Issue No: Vol. 5, No. 1 (2017)
       
  • Bee healthy! Honeybee physiology reflects landscape and supports
           conservation

    • Authors: Illing B.
      PubDate: 2017-04-24
      DOI: 10.1093/conphys/cox024
      Issue No: Vol. 5, No. 1 (2017)
       
  • Urinary profiles of progestin and androgen metabolites in female polar
           bears during parturient and non-parturient cycles

    • Authors: Knott KK; Mastromonaco GF, Owen MA, et al.
      Abstract: Due to the environmental and anthropogenic impacts that continue to threaten the reproductive success of polar bears, a more detailed understanding of their reproductive cycle is needed. Captive populations of polar bears provide an excellent opportunity to learn more about the reproductive physiology of the species. Progestin (P4) and androgen (T) metabolites in urine, and their ratio (P4:T), were examined during 11 reproductive cycles of captive female polar bears (n = 4) to characterize the steroid hormone profile during pregnancy and determine possible variations related to reproductive failure. The concentration of hormone metabolites in urine were determined through enzyme immunoassay. Reproductive cycles were classified as pregnant (n = 3), anovulatory (n = 4) and ovulatory-non-parturient (n = 4) based on the changes in urinary hormone metabolite values and cub production. In the absence of a lactational suppression of estrus, elevated androgen concentrations suggested resumption of follicular development within 3 weeks of parturition. Breeding behaviours were most often observed when androgen values were at their highest or in decline. Ovulation was identified by a return to basal androgen concentration and elevation of progestins within 1–4 weeks after breeding. As a result, urinary concentrations of progestins were greater than androgens (P4:T ratio ≥ 1.0) during ovulatory cycles whereas the P4:T ratio was <1.0 when females were anovulatory. Progestins and the P4:T ratio of parturient cycles were greatest beginning in June/July (17–20 weeks after breeding) and reached a peak at 24–37 weeks (mid-October/mid-November, 4–9 weeks before birth of cubs). Non-invasive monitoring of hormone metabolites in urine provided a rapid determination of endocrine function for improved husbandry and reproductive management of polar bears in captivity. Further research is warranted to understand the reproductive endocrinology of polar bears and its impact on conservation and management of this species in captivity and the wild.
      PubDate: 2017-04-24
      DOI: 10.1093/conphys/cox023
      Issue No: Vol. 5, No. 1 (2017)
       
  • Habitat disturbance results in chronic stress and impaired health status
           in forest-dwelling paleotropical bats

    • Authors: Seltmann A; Czirják GÁ, Courtiol A, et al.
      Abstract: Anthropogenic habitat disturbance is a major threat to biodiversity worldwide. Yet, before population declines are detectable, individuals may suffer from chronic stress and impaired immunity in disturbed habitats, making them more susceptible to pathogens and adverse weather conditions. Here, we tested in a paleotropical forest with ongoing logging and fragmentation, whether habitat disturbance influences the body mass and immunity of bats. We measured and compared body mass, chronic stress (indicated by neutrophil to lymphocyte ratios) and the number of circulating immune cells between several bat species with different roost types living in recovering areas, actively logged forests, and fragmented forests in Sabah, Malaysia. In a cave-roosting species, chronic stress levels were higher in individuals from fragmented habitats compared with conspecifics from actively logged areas. Foliage-roosting species showed a reduced body mass and decrease in total white blood cell counts in actively logged areas and fragmented forests compared with conspecifics living in recovering habitats. Our study highlights that habitat disturbance may have species-specific effects on chronic stress and immunity in bats that are potentially related to the roost type. We identified foliage-roosting species as particularly sensitive to forest habitat deterioration. These species may face a heightened extinction risk in the near future if anthropogenic habitat alterations continue.
      PubDate: 2017-04-05
      DOI: 10.1093/conphys/cox020
      Issue No: Vol. 5, No. 1 (2017)
       
  • Can local adaptation explain varying patterns of herbivory tolerance in a
           recently introduced woody plant in North America'

    • Authors: Long RW; Bush SE, Grady KC, et al.
      Abstract: Patterns of woody-plant mortality have been linked to global-scale environmental changes, such as extreme drought, heat stress, more frequent and intense fires, and episodic outbreaks of insects and pathogens. Although many studies have focussed on survival and mortality in response to specific physiological stresses, little attention has been paid to the role of genetic heritability of traits and local adaptation in influencing patterns of plant mortality, especially in non-native species. Tamarix spp. is a dominant, non-native riparian tree in western North America that is experiencing dieback in some areas of its range due to episodic herbivory by the recently introduced northern tamarisk leaf beetle (Diorhabda carinulata). We propose that genotype × environment interactions largely underpin current and future patterns of Tamarix mortality. We anticipate that (i) despite its recent introduction, and the potential for significant gene flow, Tamarix in western North America is generally adapted to local environmental conditions across its current range in part due to hybridization of two species; (ii) local adaptation to specific climate, soil and resource availability will yield predictable responses to episodic herbivory; and (iii) the ability to cope with a combination of episodic herbivory and increased aridity associated with climate change will be largely based on functional tradeoffs in resource allocation. This review focusses on the potential heritability of plant carbon allocation patterns in Tamarix, focussing on the relative contribution of acquired carbon to non-structural carbohydrate (NSC) pools versus other sinks as the basis for surviving episodic disturbance. Where high aridity and/or poor edaphic position lead to chronic stress, NSC pools may fall below a minimum threshold because of an imbalance between the supply of carbon and its demand by various sinks. Identifying patterns of local adaptation of traits related to resource allocation will improve forecasting of Tamarix population susceptibility to episodic herbivory.
      PubDate: 2017-03-28
      DOI: 10.1093/conphys/cox016
      Issue No: Vol. 5, No. 1 (2017)
       
  • Capture severity, infectious disease processes and sex influence
           post-release mortality of sockeye salmon bycatch

    • Authors: Teffer AK; Hinch SG, Miller KM, et al.
      Abstract: Bycatch is a common occurrence in heavily fished areas such as the Fraser River, British Columbia, where fisheries target returning adult Pacific salmon (Oncorhynchus spp.) en route to spawning grounds. The extent to which these encounters reduce fish survival through injury and physiological impairment depends on multiple factors including capture severity, river temperature and infectious agents. In an effort to characterize the mechanisms of post-release mortality and address fishery and managerial concerns regarding specific regulations, wild-caught Early Stuart sockeye salmon (Oncorhynchus nerka) were exposed to either mild (20 s) or severe (20 min) gillnet entanglement and then held at ecologically relevant temperatures throughout their period of river migration (mid–late July) and spawning (early August). Individuals were biopsy sampled immediately after entanglement and at death to measure indicators of stress and immunity, and the infection intensity of 44 potential pathogens. Biopsy alone increased mortality (males: 33%, females: 60%) when compared with non-biopsied controls (males: 7%, females: 15%), indicating high sensitivity to any handling during river migration, especially among females. Mortality did not occur until 5–10 days after entanglement, with severe entanglement resulting in the greatest mortality (males: 62%, females: 90%), followed by mild entanglement (males: 44%, females: 70%). Infection intensities of Flavobacterium psychrophilum and Ceratonova shasta measured at death were greater in fish that died sooner. Physiological indicators of host stress and immunity also differed depending on longevity, and indicated anaerobic metabolism, osmoregulatory failure and altered immune gene regulation in premature mortalities. Together, these results implicate latent effects of entanglement, especially among females, resulting in mortality days or weeks after release. Although any entanglement is potentially detrimental, reducing entanglement durations can improve post-release survival.
      PubDate: 2017-03-28
      DOI: 10.1093/conphys/cox017
      Issue No: Vol. 5, No. 1 (2017)
       
  • The costs of being big in a warmer world

    • Authors: Komoroske LM.
      PubDate: 2017-03-24
      DOI: 10.1093/conphys/cox022
      Issue No: Vol. 5, No. 1 (2017)
       
  • Compatibility of preparatory procedures for the analysis of cortisol
           concentrations and stable isotope ( δ 13 C, δ 15 N) ratios: a test on
           brown bear hair

    • Authors: Sergiel A; Hobson KA, Janz DM, et al.
      Abstract: The measurement of naturally occurring glucocorticoids and stable isotopes of several elements has gained importance in wildlife studies in recent decades and opened a myriad of ecological applications. Cortisol and stable isotopes equilibrate in animal tissues over periods of integration related to the growth rate of the tissue, providing information reflecting systemic cortisol secretion and dietary intake. Sample preparation shares the common step of first cleaning the sample of external contamination. However, it is not well understood how different solvents used in sample preparation affect isotopic and cortisol values, and whether it is safe to follow the same procedures for both measures to optimize analyses of the same sample. We conducted an experiment to compare different preparation protocols for the analysis of cortisol concentrations and stable carbon (δ13C) and nitrogen (δ15N) isotope ratios in hair. Hair samples from 12 brown bears (Ursus arctos) were each divided into five aliquots; two aliquots were rinsed with a 2:1 chloroform:methanol (v/v) mixture with one aliquot ground prior to cortisol analysis and the other left intact for stable isotope analyses; two aliquots were washed with methanol with one aliquot ground prior to cortisol analysis and the other left intact for stable isotope analyses; and one aliquot washed with methanol and ground prior to stable isotope analyses. The cortisol, δ13C and δ15N values remained consistent following all treatments. Our results indicate that hair samples rinsed with a 2:1 chloroform:methanol mixture or washed with methanol can be used for both types of analyses. Further, hair that has been ground in a standard hair cortisol procedure can also be used for stable isotope analysis. This information is important for improving laboratory efficiency and compatibility of procedures used for wildlife physiological ecology studies where concurrent measurements of cortisol and stable isotopes in hair are required.
      PubDate: 2017-03-24
      DOI: 10.1093/conphys/cox021
      Issue No: Vol. 5, No. 1 (2017)
       
  • The effects of elevated temperature and ocean acidification on the
           metabolic pathways of notothenioid fish

    • Authors: Enzor LA; Hunter EM, Place SP.
      Abstract: The adaptations used by notothenioid fish to combat extreme cold may have left these fish poorly poised to deal with a changing environment. As such, the expected environmental perturbations brought on by global climate change have the potential to significantly affect the energetic demands and subsequent cellular processes necessary for survival. Despite recent lines of evidence demonstrating that notothenioid fish retain the ability to acclimate to elevated temperatures, the underlying mechanisms responsible for temperature acclimation in these fish remain largely unknown. Furthermore, little information exists on the capacity of Antarctic fish to respond to changes in multiple environmental variables. We have examined the effects of increased temperature and pCO2 on the rate of oxygen consumption in three notothenioid species, Trematomus bernacchii, Pagothenia borchgrevinki, and Trematomus newnesi. We combined these measurements with analysis of changes in aerobic and anaerobic capacity, lipid reserves, fish condition, and growth rates to gain insight into the metabolic cost associated with acclimation to this dual stress. Our findings indicated that temperature is the major driver of the metabolic responses observed in these fish and that increased pCO2 plays a small, contributing role to the energetic costs of the acclimation response. All three species displayed varying levels of energetic compensation in response to the combination of elevated temperature and pCO2. While P. borchgrevinki showed nearly complete compensation of whole animal oxygen consumption rates and aerobic capacity, T. newnesi and T. bernacchii displayed only partial compensation in these metrics, suggesting that at least some notothenioids may require physiological trade-offs to fully offset the energetic costs of long-term acclimation to climate change related stressors.
      PubDate: 2017-03-24
      DOI: 10.1093/conphys/cox019
      Issue No: Vol. 5, No. 1 (2017)
       
  • Conservation at a slow pace: terrestrial gastropods facing fast-changing
           climate

    • Authors: Nicolai A; Ansart A.
      Abstract: The climate is changing rapidly, and terrestrial ectotherms are expected to be particularly vulnerable to changes in temperature and water regime, but also to an increase in extreme weather events in temperate regions. Physiological responses of terrestrial gastropods to climate change are poorly studied. This is surprising, because they are of biodiversity significance among litter-dwelling species, playing important roles in ecosystem function, with numerous species being listed as endangered and requiring efficient conservation management. Through a summary of our ecophysiological work on snail and slug species, we gained some insights into physiological and behavioural responses to climate change that we can organize into the following four threat categories. (i) Winter temperature and snow cover. Terrestrial gastropods use different strategies to survive sub-zero temperatures in buffered refuges, such as the litter or the soil. Absence of the insulating snow cover exposes species to high variability in temperature. The extent of specific cold tolerance might influence the potential of local extinction, but also of invasion. (ii) Drought and high temperature. Physiological responses involve high-cost processes that protect against heat and dehydration. Some species decrease activity periods, thereby reducing foraging and reproduction time. Related costs and physiological limits are expected to increase mortality. (iii) Extreme events. Although some terrestrial gastropod communities can have a good resilience to fire, storms and flooding, an increase in the frequency of those events might lead to community impoverishment. (iv) Habitat loss and fragmentation. Given that terrestrial gastropods are poorly mobile, landscape alteration generally results in an increased risk of local extinction, but responses are highly variable between species, requiring studies at the population level. There is a great need for studies involving non-invasive methods on the plasticity of physiological and behavioural responses and the ability for local adaptation, considering the spatiotemporally heterogeneous climatic landscape, to allow efficient management of ecosystems and conservation of biodiversity.
      PubDate: 2017-03-18
      DOI: 10.1093/conphys/cox007
      Issue No: Vol. 5, No. 1 (2017)
       
  • Lingering effects of contraception management on feral mare ( Equus
           caballus ) fertility and social behavior

    • Authors: Nuñez CV; Adelman JS, Carr HA, et al.
      Abstract: Due to the extirpation of their natural predators, feral horse populations have expanded across the United States, necessitating their management. Contraception of females (mares) with porcine zona pellucida (PZP) is a popular option; however, effects to physiology and behavior can be substantial. On Shackleford Banks, North Carolina, USA, treated mares have exhibited cycling during the non-breeding season and demonstrated decreased fidelity to the band stallion, but PZP's long-term effects on mare physiology and behavior remain largely unexplored. After the contraception program was suspended in this population, we examined how prior exposure to varying levels of PZP treatment impacted (1) foaling probability and foaling dates (a proxy for ovulatory cycling) from 2009 to 2014 and (2) mare fidelity to the band stallion and reproductive behavior during 2013 and 2015. Additionally, we evaluated the effects of time since the mares’ last treatment on these factors. Mares receiving any level of prior PZP treatment were less likely to foal than were untreated mares. Among mares that received 1–3 PZP applications, foaling probability increased with time since last treatment before declining, at ~6 years post-treatment. Mares that received 4+ applications did not exhibit a significant increase in foaling probability with time since last treatment. Moreover, previously treated mares continued to conceive later than did untreated mares. Finally, mares previously receiving 4+ treatments changed groups more often than did untreated mares, though reproductive behavior did not differ with contraception history. Our results suggest that although PZP-induced subfertility and its associated behavioral effects can persist after the cessation of treatment, these effects can be ameliorated for some factors with less intense treatment. Careful consideration to the frequency of PZP treatment is important to maintaining more naturally functioning populations; the ability to manage populations adaptively may be compromised if females are kept subfertile for extended periods of time.
      PubDate: 2017-03-18
      DOI: 10.1093/conphys/cox018
      Issue No: Vol. 5, No. 1 (2017)
       
  • Effects of ambient oxygen and size-selective mortality on growth and
           maturation in guppies

    • Authors: Diaz Pauli B; Kolding J, Jeyakanth G, et al.
      Abstract: Growth, onset of maturity and investment in reproduction are key traits for understanding variation in life-history strategies. Many environmental factors affect variation in these traits, but for fish, hypoxia and size-dependent mortality have become increasingly important because of human activities, such as increased nutrient enrichment (eutrophication), climate warming and selective fishing. Here, we study experimentally the effect of oxygen availability on maturation and growth in guppies (Poecilia reticulata) from two different selected lines, one subjected to positive and the other negative size-dependent fishing. This is the first study to assess the effects of both reduced ambient oxygen and size-dependent mortality in fish. We show that reduced ambient oxygen led to stunting, early maturation and high reproductive investment. Likewise, lineages that had been exposed to high mortality of larger-sized individuals displayed earlier maturation at smaller size, greater investment in reproduction and faster growth. These life-history changes were particularly evident for males. The widely reported trends towards earlier maturation in wild fish populations are often interpreted as resulting from size-selective fishing. Our results highlight that reduced ambient oxygen, which has received little experimental investigation to date, can lead to similar phenotypic changes. Thus, changes in ambient oxygen levels can be a confounding factor that occurs in parallel with fishing, complicating the causal interpretation of changes in life-history traits. We believe that better disentangling of the effects of these two extrinsic factors, which increasingly affect many freshwater and marine ecosystems, is important for making more informed management decisions.
      PubDate: 2017-03-14
      DOI: 10.1093/conphys/cox010
      Issue No: Vol. 5, No. 1 (2017)
       
  • A right whale pootree: classification trees of faecal hormones identify
           reproductive states in North Atlantic right whales ( Eubalaena glacialis )
           

    • Authors: Corkeron P; Rolland RM, Hunt KE, et al.
      Abstract: Immunoassay of hormone metabolites extracted from faecal samples of free-ranging large whales can provide biologically relevant information on reproductive state and stress responses. North Atlantic right whales (Eubalaena glacialis Müller 1776) are an ideal model for testing the conservation value of faecal metabolites. Almost all North Atlantic right whales are individually identified, most of the population is sighted each year, and systematic survey effort extends back to 1986. North Atlantic right whales number <500 individuals and are subject to anthropogenic mortality, morbidity and other stressors, and scientific data to inform conservation planning are recognized as important. Here, we describe the use of classification trees as an alternative method of analysing multiple-hormone data sets, building on univariate models that have previously been used to describe hormone profiles of individual North Atlantic right whales of known reproductive state. Our tree correctly classified the age class, sex and reproductive state of 83% of 112 faecal samples from known individual whales. Pregnant females, lactating females and both mature and immature males were classified reliably using our model. Non-reproductive [i.e. ‘resting’ (not pregnant and not lactating) and immature] females proved the most unreliable to distinguish. There were three individual males that, given their age, would traditionally be considered immature but that our tree classed as mature males, possibly calling for a re-evaluation of their reproductive status. Our analysis reiterates the importance of considering the reproductive state of whales when assessing the relationship between cortisol concentrations and stress. Overall, these results confirm findings from previous univariate statistical analyses, but with a more robust multivariate approach that may prove useful for the multiple-analyte data sets that are increasingly used by conservation physiologists.
      PubDate: 2017-03-09
      DOI: 10.1093/conphys/cox006
      Issue No: Vol. 5, No. 1 (2017)
       
  • Rethinking the approach to viability monitoring in seed genebanks

    • Authors: Hay FR; Whitehouse KJ.
      Abstract: Seed viability monitoring, usually through a germination test, is a key aspect of genebank management; a low viability result triggers the regeneration of an accession in order to ensure that the genetic diversity of the accession is conserved and available for distribution. However, regular viability monitoring of large collections is costly in terms of seeds, labour and other resources. Genebanks differ in how they conduct their viability monitoring and how they collect, manage and store the data that are generated. In this article, we propose alternatives to the current norm of conducting an initial germination test soon after arrival at the genebank and then testing after regular, set storage intervals, as recommended in the Food and Agriculture Organization's Genebank Standards for Plant Genetic Resources for Food and Agriculture. We use real data from the International Rice Genebank (held at the International Rice Research Institute) to illustrate some of the issues regarding the accuracy and reliability of germination test results, in particular when they are used to predict the longevity of a seed lot in storage and to set viability monitoring intervals. We suggest the use of seed storage experiments on samples of seeds to identify which seed lots from a particular crop season to test first. We also give advice on the use of sequential testing schemes potentially to reduce the number of seeds used for viability testing; the use of tolerance tables to identify unlikely results when samples are subdivided into replicates; and what data to include in a genebank management database to improve the management of seed collections.
      PubDate: 2017-03-04
      DOI: 10.1093/conphys/cox009
      Issue No: Vol. 5, No. 1 (2017)
       
  • Stress response to handling is short lived but may reflect personalities
           in a wild, Critically Endangered tortoise species

    • Authors: Currylow AT; Louis EE, Crocker DE.
      Abstract: We investigated the acute stress response associated with animal personalities by measuring plasma glucocorticoids throughout handling and collected ~2 years of movement and behavioural data in a wild, Critically Endangered animal, Astrochelys radiata (radiated tortoise). To determine whether our standard, brief conscientious handling procedures induce a stress response in our target species, we applied a stressor by way of initial animal processing and deployment of telemetry equipment. During surveys and processing, we sampled animals immediately upon detection, again after completing transmitter attachment and processing, and a final time the following day. We then used radiotelemetry to follow a subset of the animals for 22 months while collecting behavioural, climatic and location data. We found that brief and conscientious handling did not illicit consistent changes in plasma concentrations of the stress hormone corticosterone (CORT) but did reveal tremendous individual variation in response. The CORT concentration ranged more than 200-fold after imposing the stressor and returned to near-baseline values by the following day. When we accounted for the wide variation by calculating the degree of each individual's stress response relative to its baseline over its processing time, we discovered two non-overlapping physiological response types; those in which CORT concentrations increased dramatically in response to handling (219 ± 89.8 pg/ml/min) and those in which CORT varied only slightly (5.3 ± 8.9 pg/ml/min). The response types (strong vs. mild) also predicted body condition, home range size, activity, and behavioural tendencies. The degree of the individual's stress response in this species may be one component of correlated physiological and behavioural traits (animal personalities), which have previously been obscured in other chelonian studies by the use of mean values and should be considered in future conservation management applications for chelonian species.
      PubDate: 2017-03-04
      DOI: 10.1093/conphys/cox008
      Issue No: Vol. 5, No. 1 (2017)
       
  • Obtaining accurate glucose measurements from wild animals under field
           conditions: comparing a hand held glucometer with a standard laboratory
           technique in grey seals

    • Authors: Bennett KA; Turner LM, Millward S, et al.
      Abstract: Glucose is an important metabolic fuel and circulating levels are tightly regulated in most mammals, but can drop when body fuel reserves become critically low. Glucose is mobilized rapidly from liver and muscle during stress in response to increased circulating cortisol. Blood glucose levels can thus be of value in conservation as an indicator of nutritional status and may be a useful, rapid assessment marker for acute or chronic stress. However, seals show unusual glucose regulation: circulating levels are high and insulin sensitivity is limited. Accurate blood glucose measurement is therefore vital to enable meaningful health and physiological assessments in captive, wild or rehabilitated seals and to explore its utility as a marker of conservation relevance in these animals. Point-of-care devices are simple, portable, relatively cheap and use less blood compared with traditional sampling approaches, making them useful in conservation-related monitoring. We investigated the accuracy of a hand-held glucometer for ‘instant’ field measurement of blood glucose, compared with blood drawing followed by laboratory testing, in wild grey seals (Halichoerus grypus), a species used as an indicator for Good Environmental Status in European waters. The glucometer showed high precision, but low accuracy, relative to laboratory measurements, and was least accurate at extreme values. It did not provide a reliable alternative to plasma analysis. Poor correlation between methods may be due to suboptimal field conditions, greater and more variable haematocrit, faster erythrocyte settling rate and/or lipaemia in seals. Glucometers must therefore be rigorously tested before use in new species and demographic groups. Sampling, processing and glucose determination methods have major implications for conclusions regarding glucose regulation, and health assessment in seals generally, which is important in species of conservation concern and in development of circulating glucose as a marker of stress or nutritional state for use in management and monitoring.
      PubDate: 2017-02-27
      DOI: 10.1093/conphys/cox013
      Issue No: Vol. 5, No. 1 (2017)
       
  • Physiological effects of environmentally relevant, multi-day thermal
           stress on wild juvenile Atlantic salmon ( Salmo salar )

    • Authors: Corey E; Linnansaari T, Cunjak RA, et al.
      Abstract: The frequency of extreme thermal events in temperate freshwater systems is expected to increase alongside global surface temperature. The Miramichi River, located in eastern Canada, is a prominent Atlantic salmon (Salmo salar) river where water temperatures can exceed the proposed upper thermal limit for the species (~27°C). Current legislation closes the river to recreational angling when water temperatures exceed 20°C for two consecutive nights. We aimed to examine how natural thermal variation, representative of extreme high thermal events, affected the thermal tolerance and physiology of wild, juvenile Atlantic salmon. We acclimated fish to four thermal cycles, characteristic of real-world thermal conditions while varying daily thermal minima (16°C, 18°C, 20°C or 22°C) and diel thermal fluctuation (e.g. Δ5°C–Δ9°C). In each cycling condition, we assessed the role that thermal minima played on the acute thermal tolerance (critical thermal maximum, (CTMax)), physiological (e.g. heat shock protein 70 (HSP70), ubiquitin) and energetic (e.g. hepatic glycogen, blood glucose and lactate) status of juvenile Atlantic salmon throughout repeated thermal cycles. Exposure to 16–21°C significantly increased CTMax (+0.9°C) compared to a stable acclimation temperature (16°C), as did exposure to diel thermal fluctuations of 18–27°C, 20–27°C and 22–27°C, yet repeated exposure provided no further increases in acute thermal tolerance. In comparison to the reference condition (16–21°C), consecutive days of high temperature cycling with different thermal minima resulted in significant increases in HSP70 and ubiquitin, a significant decrease in liver glycogen, and no significant cumulative effect on either blood glucose or lactate. However, comparison between thermally taxed treatments suggested the diel thermal minima had little influence on the physiological or energetic response of juvenile salmon, despite the variable thermal cycling condition. Our results suggest that relatively cooler night temperatures in the summer months may play a limited role in mitigating physiological stress throughout warm diel cycle events.
      PubDate: 2017-02-27
      DOI: 10.1093/conphys/cox014
      Issue No: Vol. 5, No. 1 (2017)
       
  • Validation of a portable, waterproof blood pH analyser for elasmobranchs

    • Authors: Talwar B; Bouyoucos IA, Shipley O, et al.
      Abstract: Quantifying changes in blood chemistry in elasmobranchs can provide insights into the physiological insults caused by anthropogenic stress, and can ultimately inform conservation and management strategies. Current methods for analysing elasmobranch blood chemistry in the field are often costly and logistically challenging. We compared blood pH values measured using a portable, waterproof pH meter (Hanna Instruments HI 99161) with blood pH values measured by an i-STAT system (CG4+ cartridges), which was previously validated for teleost and elasmobranch fishes, to gauge the accuracy of the pH meter in determining whole blood pH for the Cuban dogfish (Squalus cubensis) and lemon shark (Negaprion brevirostris). There was a significant linear relationship between values derived via the pH meter and the i-STAT for both species across a wide range of pH values and temperatures (Cuban dogfish: 6.8–7.1 pH 24–30°C; lemon sharks: 7.0–7.45 pH 25–31°C). The relative error in the pH meter's measurements was ~±2.7%. Using this device with appropriate correction factors and consideration of calibration temperatures can result in both a rapid and accurate assessment of whole blood pH, at least for the two elasmobranch species examined here. Additional species should be examined in the future across a wide range of temperatures to determine whether correction factors are universal.
      PubDate: 2017-02-27
      DOI: 10.1093/conphys/cox012
      Issue No: Vol. 5, No. 1 (2017)
       
  • Down the rabbit hole: how complex do eco-physiological models need to
           be'

    • Authors: Tomlinson S.
      PubDate: 2017-02-23
      DOI: 10.1093/conphys/cox015
      Issue No: Vol. 5, No. 1 (2017)
       
  • What if you can't sense your enemy… and your enemy is an invasive
           predator'

    • Authors: Rummer JL.
      PubDate: 2017-02-23
      DOI: 10.1093/conphys/cox011
      Issue No: Vol. 5, No. 1 (2017)
       
  • Physiology can contribute to better understanding, management, and
           conservation of coral reef fishes

    • Authors: Illing B; Rummer JL.
      Abstract: Coral reef fishes, like many other marine organisms, are affected by anthropogenic stressors such as fishing and pollution and, owing to climate change, are experiencing increasing water temperatures and ocean acidification. Against the backdrop of these various stressors, a mechanistic understanding of processes governing individual organismal performance is the first step for identifying drivers of coral reef fish population dynamics. In fact, physiological measurements can help to reveal potential cause-and-effect relationships and enable physiologists to advise conservation management by upscaling results from cellular and individual organismal levels to population levels. Here, we highlight studies that include physiological measurements of coral reef fishes and those that give advice for their conservation. A literature search using combined physiological, conservation and coral reef fish key words resulted in ~1900 studies, of which only 99 matched predefined requirements. We observed that, over the last 20 years, the combination of physiological and conservation aspects in studies on coral reef fishes has received increased attention. Most of the selected studies made their physiological observations at the whole organism level and used their findings to give conservation advice on population dynamics, habitat use or the potential effects of climate change. The precision of the recommendations differed greatly and, not surprisingly, was least concrete when studies examined the effects of projected climate change scenarios. Although more and more physiological studies on coral reef fishes include conservation aspects, there is still a lack of concrete advice for conservation managers, with only very few published examples of physiological findings leading to improved management practices. We conclude with a call to action to foster better knowledge exchange between natural scientists and conservation managers to translate physiological findings more effectively in order to obtain evidence-based and adaptive management strategies for the conservation of coral reef fishes.
      PubDate: 2017-02-23
      DOI: 10.1093/conphys/cox005
      Issue No: Vol. 5, No. 1 (2017)
       
  • Intrinsic and extrinsic influences on standard metabolic rates of three
           species of Australian otariid

    • Authors: Ladds MA; Slip DJ, Harcourt RG.
      Abstract: The study of marine mammal energetics can shed light on how these animals might adapt to changing environments. Their physiological potential to adapt will be influenced by extrinsic factors, such as temperature, and by intrinsic factors, such as sex and reproduction. We measured the standard metabolic rate (SMR) of males and females of three Australian otariid species (two Australian fur seals, three New Zealand fur seals and seven Australian sea lions). Mean SMR ranged from 0.47 to 1.05 l O2 min−1, which when adjusted for mass was from 5.33 to 7.44 ml O2 min−1 kg−1. We found that Australian sea lion mass-specific SMR (sSMR; in millilitres of oxygen per minute per kilogram) varied little in response to time of year or moult, but was significantly influenced by sex and water temperature. Likewise, sSMR of Australian and New Zealand fur seals was also influenced by sex and water temperature, but also by time of year (pre-moult, moult or post-moult). During the moult, fur seals had significantly higher sSMR than at other times of the year, whereas there was no discernible effect of moult for sea lions. For both groups, females had higher sSMR than males, but sea lions and fur seals showed different responses to changes in water temperature. The sSMR of fur seals increased with increasing water temperature, whereas sSMR of sea lions decreased with increasing water temperature. There were no species differences when comparing animals of the same sex. Our study suggests that fur seals have more flexibility in their physiology than sea lions, perhaps implying that they will be more resilient in a changing environment.
      PubDate: 2017-02-21
      DOI: 10.1093/conphys/cow074
      Issue No: Vol. 5, No. 1 (2017)
       
  • Conservation physiology and the quest for a ‘good’
           Anthropocene

    • Authors: Madliger CL; Franklin CE, Hultine KR, et al.
      Abstract: It has been proposed that we are now living in a new geological epoch known as the Anthropocene, which is specifically defined by the impacts that humans are having on the Earth's biological diversity and geology. Although the proposal of this term was borne out of an acknowledgement of the negative changes we are imparting on the globe (e.g. climate change, pollution, coastal erosion, species extinctions), there has recently been action amongst a variety of disciplines aimed at achieving a ‘good Anthropocene’ that strives to balance societal needs and the preservation of the natural world. Here, we outline ways that the discipline of conservation physiology can help to delineate a hopeful, progressive and productive path for conservation in the Anthropocene and, specifically, achieve that vision. We focus on four primary ways that conservation physiology can contribute, as follows: (i) building a proactive approach to conservation; (ii) encouraging a pragmatic perspective; (iii) establishing an appreciation for environmental resilience; and (iv) informing and engaging the public and political arenas. As a collection of passionate individuals combining theory, technological advances, public engagement and a dedication to achieving conservation success, conservation physiologists are poised to make meaningful contributions to the productive, motivational and positive way forward that is necessary to curb and reverse negative human impact on the environment.
      PubDate: 2017-02-15
      DOI: 10.1093/conphys/cox003
      Issue No: Vol. 5, No. 1 (2017)
       
  • Non-invasive endocrine monitoring indicates seasonal variations in gonadal
           hormone metabolites in dholes ( Cuon alpinus )

    • Authors: Khonmee J; Rojanasthien S, Thitaram C, et al.
      Abstract: To date, there is no information on reproductive endocrinology of dholes (Cuon alpinus). The objectives of the present study were as follows: (i) to characterize longitudinal profiles of gonadal steroids; and (ii) to examine the relationship between gonadal hormones and sexual behaviours in dholes. Three breeding pairs and two bachelor males were included in the study. Among these, four animals (2 males and 2 females; 4 years old) were imported from The Netherlands to Thailand 3 months before the study onset; the remaining individuals (3 males and 1 female; 5–7 years old) were native born. Faecal samples were collected 3–7 days/week for 12 months, extracted and assessed for gonadal hormone metabolites using a validated enzyme immunoassay. Observations of behaviour were conducted in 30 min sessions, 3–5 days/week. For the three breeding males, testosterone was elevated (P < 0.05) from October to January in the two imported males, whereas the concentration of steroid metabolites was high from April to June and from September to November in the native male. However, there was no clear seasonal pattern of reproductive hormone in the bachelor group. Oestrogen metabolite level of imported females was elevated for 9–12 days in January, followed by a rise in progestagen concentration. For native females, oestrogen metabolites were above the basal values in April and September, each of which was followed by a rise in progestagen concentration that remained elevated for 77 and 112 days, respectively. Sexual behaviours, including solicitation, mounting and copulations, were observed during the oestrogen peak in all females. Our findings indicate that reproductive seasonality of dholes may depend on the animals’ origin and social group.
      PubDate: 2017-02-15
      DOI: 10.1093/conphys/cox001
      Issue No: Vol. 5, No. 1 (2017)
       
  • Body water conservation through selective brain cooling by the carotid
           rete: a physiological feature for surviving climate change'

    • Authors: Strauss W; Hetem RS, Mitchell D, et al.
      Abstract: Some mammals have the ability to lower their hypothalamic temperature below that of carotid arterial blood temperature, a process termed selective brain cooling. Although the requisite anatomical structure that facilitates this physiological process, the carotid rete, is present in members of the Cetartiodactyla, Felidae and Canidae, the carotid rete is particularly well developed in the artiodactyls, e.g. antelopes, cattle, sheep and goats. First described in the domestic cat, the seemingly obvious function initially attributed to selective brain cooling was that of protecting the brain from thermal damage. However, hyperthermia is not a prerequisite for selective brain cooling, and selective brain cooling can be exhibited at all times of the day, even when carotid arterial blood temperature is relatively low. More recently, it has been shown that selective brain cooling functions primarily as a water-conservation mechanism, allowing artiodactyls to save more than half of their daily water requirements. Here, we argue that the evolutionary success of the artiodactyls may, in part, be attributed to the evolution of the carotid rete and the resulting ability to conserve body water during past environmental conditions, and we suggest that this group of mammals may therefore have a selective advantage in the hotter and drier conditions associated with current anthropogenic climate change. A better understanding of how selective brain cooling provides physiological plasticity to mammals in changing environments will improve our ability to predict their responses and to implement appropriate conservation measures.
      PubDate: 2017-02-14
      DOI: 10.1093/conphys/cow078
      Issue No: Vol. 5, No. 1 (2017)
       
  • Energy metabolism in mobile, wild-sampled sharks inferred by plasma lipids

    • Authors: Gallagher AJ; Skubel RA, Pethybridge HR, et al.
      Abstract: Evaluating how predators metabolize energy is increasingly useful for conservation physiology, as it can provide information on their current nutritional condition. However, obtaining metabolic information from mobile marine predators is inherently challenging owing to their relative rarity, cryptic nature and often wide-ranging underwater movements. Here, we investigate aspects of energy metabolism in four free-ranging shark species (n = 281; blacktip, bull, nurse, and tiger) by measuring three metabolic parameters [plasma triglycerides (TAG), free fatty acids (FFA) and cholesterol (CHOL)] via non-lethal biopsy sampling. Plasma TAG, FFA and total CHOL concentrations (in millimoles per litre) varied inter-specifically and with season, year, and shark length varied within a species. The TAG were highest in the plasma of less active species (nurse and tiger sharks), whereas FFA were highest among species with relatively high energetic demands (blacktip and bull sharks), and CHOL concentrations were highest in bull sharks. Although temporal patterns in all metabolites were varied among species, there appeared to be peaks in the spring and summer, with ratios of TAG/CHOL (a proxy for condition) in all species displaying a notable peak in summer. These results provide baseline information of energy metabolism in large sharks and are an important step in understanding how the metabolic parameters can be assessed through non-lethal sampling in the future. In particular, this study emphasizes the importance of accounting for intra-specific and temporal variability in sampling designs seeking to monitor the nutritional condition and metabolic responses of shark populations.
      PubDate: 2017-02-14
      DOI: 10.1093/conphys/cox002
      Issue No: Vol. 5, No. 1 (2017)
       
  • The effect of temperature on development and behaviour of relict leopard
           frog tadpoles

    • Authors: Goldstein JA; Hoff K, Hillyard SD.
      Abstract: Relict leopard frog (Rana [Lithobates] onca) tadpoles were obtained shortly after hatching at Gosner stage 25 and raised in aquaria maintained at 15, 20, 25, 30 and 35°C. Development was arrested in the 15°C group, and survivorship declined to 64% after 191 days. However, 80% of the surviving larvae remained alive after the temperature was increased to 25°C. Of these, 96% reached metamorphosis. Survivorship of the 20, 25 and 30°C acclimation groups was 82, 94 and 66%, respectively, whereas none survived at 35°C. Time to metamorphosis was significantly shorter for the 25°C group (67 ± 1 days), followed by the 30°C (98 ± 2 days) and 20°C (264 ± 7 days) groups. A linear 66 cm thermal gradient was used to identify temperature ranges selected by tadpoles in the different acclimation groups. Five 10°C gradients (10–20, 15–25, 20–30, 25–35 and 30–40°C) were used, and time spent in the cooler, middle and warmer thirds of the gradient was compared for 10 individuals from each acclimation group. In the coolest gradient, tadpoles from all acclimation groups selected the warmer third (>17°C) of the gradient. In the warmer gradients, tadpoles from the 20 and 25°C acclimation groups selected temperatures <29°C, while those from the 30°C acclimation group selected temperatures <33°C. Maximal burst speed for all groups was greater at experimental temperatures of 25 than 15°C. Efforts to reintroduce this species to its historical range should select habitats where water temperatures between 25 and 30°C are available during the post-hatching period.
      PubDate: 2017-02-14
      DOI: 10.1093/conphys/cow075
      Issue No: Vol. 5, No. 1 (2017)
       
  • An evaluation of the use of pentosidine as a biomarker for ageing turtles

    • Authors: Iverson JB; Stahl RS, Furcolow C, et al.
      Abstract: Concentrations of the biomarker pentosidine have been shown to be useful measures of age for a number of avian and mammalian species. However, no study has examined its usefulness as an age marker in a long-lived ectotherm despite the fact that such a marker could prove useful in understanding age distributions of populations subject to conservation programmes. Therefore, we evaluated pentosidine concentrations in the interdigital webbing of 117 female yellow mud turtles (Kinosternon flavescens) at a 35 year study site in western Nebraska where nearly all turtles are of known age. Pentosidine concentrations were extraordinarily low and positively correlated with age in this turtle, but concentrations were too variable to permit precise estimates of age for turtles of unknown age. These results may reflect the remarkable physiological adaptations of this turtle to low temperatures and oxygen deprivation in a highly seasonal environment requiring prolonged hibernation. Whether pentosidine concentrations in other ectotherms occupying less seasonal environments would be more highly correlated with age remains to be determined. However, our results suggest that patterns of accumulation of pentosidine in ectotherms may be fundamentally different from those in endotherms.
      PubDate: 2017-01-27
      DOI: 10.1093/conphys/cow076
      Issue No: Vol. 5, No. 1 (2017)
       
  • Environmental and physiological correlates of the severity of clinical
           signs of snake fungal disease in a population of pigmy rattlesnakes,
           Sistrurus miliarius

    • Authors: McCoy CM; Lind CM, Farrell TM.
      Abstract: In the past decade, snake fungal disease (SFD) has been identified as an emerging threat to snake populations throughout the eastern USA. Snake fungal disease is caused by the fungus Ophidiomyces ophiodiicola. Little is known regarding the environmental or physiological variables that affect host vulnerability and O. ophiodiicola virulence in wild snake populations. Understanding the intrinsic and extrinsic factors that correlate with infection severity is a key first step in understanding host–pathogen dynamics. Host vulnerability may vary seasonally as a result of thermal conditions or energetic trade-offs, and pathogen growth rates or dispersal may be tied to seasonal trends in climate. To determine whether season, environmental temperature or energetic trade-offs associated with life-history stage influence an individual's susceptibility to infection, we monitored the severity of clinical signs of SFD, surface air temperature, reproductive status, body condition and serum complement activity (plasma bactericidal ability) in free-ranging pigmy rattlesnakes, Sistrurus miliarius, over the course of 18 months. Seasonal increases in the severity of clinical signs of SFD were correlated negatively with monthly air surface temperature and the mean body condition of the population. Bactericidal ability varied seasonally, but pigmy rattlesnakes suffering from active SFD infections did not exhibit deficits in innate immune function. Infected snakes were in significantly lower body condition when compared with the general population, but seasonal patterns in the mean body condition of the population were not driven by seasonal patterns of infection severity. Our results highlight the potential importance of the thermal environment and energetic status in determining infection severity and outcomes and the need for managers and researchers to consider seasonality of symptom presentation when the goal is to identify the prevalence or incidence of SFD in populations.
      PubDate: 2017-01-27
      DOI: 10.1093/conphys/cow077
      Issue No: Vol. 5, No. 1 (2017)
       
  • Expression of genes involved in brain GABAergic neurotransmission in
           three-spined stickleback exposed to near-future CO 2

    • Authors: Lai F; Fagernes CE, Jutfelt F, et al.
      PubDate: 2017-01-20
      DOI: 10.1093/conphys/cox004
      Issue No: Vol. 5, No. 1 (2017)
       
  • Reflections and progress in conservation physiology

    • Authors: Cooke SJ; Hultine KR, Rummer JL, et al.
      PubDate: 2017-01-04
      DOI: 10.1093/conphys/cow071
      Issue No: Vol. 5, No. 1 (2017)
       
  • Corticosterone, inflammation, immune status and telomere length in
           frigatebird nestlings facing a severe herpesvirus infection

    • Authors: Sebastiano M; Eens M, Angelier F, et al.
      Abstract: Herpesvirus outbreaks are common in natural animal populations, but little is known about factors that favour the infection and its consequences for the organism. In this study, we examined the pathophysiological consequences of a disease probably attributable to herpesvirus infection for several markers of immune function, corticosterone, telomere length and inflammation. In addition, we assessed whether any markers used in this study might be associated with the occurrence of visible clinical signs of the disease and its impact on short-term survival perspectives. To address our questions, in spring 2015, we collected blood samples from nestlings of the magnificent frigatebird (Fregata magnificens) that were free of any clinical signs or showed visible signs of the disease. We found that the plasma concentration of haptoglobin was strongly associated with the infection status and could predict probabilities of survival. We also found that nestlings with clinical signs had lower baseline corticosterone concentrations and similar telomere length compared with healthy nestlings, whereas we did not find any association of the infection status with innate immune defenses or with nitric oxide concentration. Overall, our results suggest that the plasma concentration of haptoglobin might be a valuable tool to assess survival probabilities of frigatebird nestlings facing a herpesvirus outbreak.
      PubDate: 2017-01-04
      DOI: 10.1093/conphys/cow073
      Issue No: Vol. 5, No. 1 (2017)
       
  • Unusual aerobic performance at high temperatures in juvenile Chinook
           salmon, Oncorhynchus tshawytscha

    • Authors: Poletto JB; Cocherell DE, Baird SE, et al.
      Abstract: Understanding how the current warming trends affect fish populations is crucial for effective conservation and management. To help define suitable thermal habitat for juvenile Chinook salmon, the thermal performance of juvenile Chinook salmon acclimated to either 15 or 19°C was tested across a range of environmentally relevant acute temperature changes (from 12 to 26°C). Swim tunnel respirometers were used to measure routine oxygen uptake as a measure of routine metabolic rate (RMR) and oxygen uptake when swimming maximally as a measure of maximal metabolic rate (MMR) at each test temperature. We estimated absolute aerobic scope (AAS = MMR − RMR), the capacity to supply oxygen beyond routine needs, as well as factorial aerobic scope (FAS = MMR/RMR). All fish swam at a test temperature of 23°C regardless of acclimation temperature, but some mortality occurred at 25°C during MMR measurements. Overall, RMR and MMR increased with acute warming, but aerobic capacity was unaffected by test temperatures up to 23°C in both acclimation groups. The mean AAS for fish acclimated and tested at 15°C (7.06 ± 1.76 mg O2 kg−1 h−1) was similar to that measured for fish acclimated and tested at 19°C (8.80 ± 1.42 mg O2 kg−1 h−1). Over the entire acute test temperature range, while MMR and AAS were similar for the two acclimation groups, RMR was significantly lower and FAS consequently higher at the lower test temperatures for the fish acclimated at 19°C. Thus, this stock of juvenile Chinook salmon shows an impressive aerobic capacity when acutely warmed to temperatures close to their upper thermal tolerance limit, regardless of the acclimation temperature. These results are compared with those for other salmonids, and the implications of our findings for informing management actions are discussed.
      PubDate: 2017-01-04
      DOI: 10.1093/conphys/cow067
      Issue No: Vol. 5, No. 1 (2017)
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs
Your IP address: 54.80.157.133
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2016