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Colborne S, Peiman KS, Birnie-Gauvin K, Larsen MH, Aarestrup K, Cooke SJ. Effects of pre-winter cortisol exposure on condition, diet, and morphology of wild juvenile brown trout (Salmo trutta). JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:282-292. [PMID: 38238913 DOI: 10.1002/jez.2781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 01/03/2024] [Accepted: 01/04/2024] [Indexed: 02/27/2024]
Abstract
Winter is an energetically challenging period for many animals in temperate regions because of the relatively harsh environmental conditions and reduction in food availability during this season. Moreover, stressors experienced by individuals in the fall can affect their subsequent foraging strategy and energy stores after exposure has ended, referred to as carryover effects. We used exogenous cortisol manipulation of wild juvenile brown trout (Salmo trutta) in the fall to simulate a physiological stress response and then investigated short-term (2 weeks) and long-term (4 months) effects on condition metrics (hepatosomatic index and water muscle content), diet (stomach contents and stable isotopes), and morphology during growth in freshwater. We revealed some short-term impacts, likely due to handling stress, and long-term (seasonal) changes in diet, likely reflecting prey availability. Unfortunately, we had very few recaptures of cortisol-treated fish at long-term sampling, limiting detailed analysis about cortisol effects at that time point. Nonetheless, the fish that were sampled showed elevated stable isotopes, suggestive of a cortisol effect long after exposure. This is one of few studies to investigate whether cortisol influences foraging and morphology during juvenile growth, thus extending the knowledge of proximate mechanisms influencing ecologically-relevant phenotypes.
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Affiliation(s)
- Scott Colborne
- Department of Fisheries and Wildlife, Quantitative Fisheries Center, Michigan State University, East Lansing, Michigan, USA
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario, Canada
| | - Kathryn S Peiman
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Ontario, Canada
| | - Kim Birnie-Gauvin
- Section for Freshwater Fisheries and Ecology, National Institute for Aquatic Resources, Technical University of Denmark, Silkeborg, Denmark
| | - Martin H Larsen
- Section for Freshwater Fisheries and Ecology, National Institute for Aquatic Resources, Technical University of Denmark, Silkeborg, Denmark
| | - Kim Aarestrup
- Section for Freshwater Fisheries and Ecology, National Institute for Aquatic Resources, Technical University of Denmark, Silkeborg, Denmark
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Institute of Environmental and Interdisciplinary Science, Carleton University, Ottawa, Ontario, Canada
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Carbajal A, Lawrence MJ, Gilmour KM, Lopez-Bejar M, Cooke SJ. Evaluation of the effects of exogenous cortisol manipulation and the glucocorticoid antagonist, RU486, on the exploratory tendency of bluegill sunfish (Lepomis macrochirus). FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:1187-1198. [PMID: 37819483 PMCID: PMC10757703 DOI: 10.1007/s10695-023-01250-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023]
Abstract
In teleost fishes, activation of the hypothalamic-pituitary-interrenal axis leads to an elevation of circulating cortisol levels as a primary stress response. While acute elevation of cortisol is generally beneficial, long-term elevation, a common characteristic of chronic stress, may lead to detrimental effects on health and physiological performance in fishes. Some stress-mediated behavioural shifts, such as variation along the shy-boldness axis in fish, may influence individual fitness. The present study evaluated the role of cortisol and its mechanisms of action in the exploratory behaviour of the bluegill sunfish (Lepomis macrochirus). Fish were implanted with cocoa butter alone (sham treatment), or cocoa butter containing cortisol, or cortisol and the glucocorticoid receptor antagonist, RU486. A control (untreated) group was also used. Animals were held for 48 h following treatment and then were subjected to a Z-maze trial to characterize the exploratory behaviour. Cortisol treatment had no measurable effect on the exploratory behaviour of bluegill sunfish. Despite presenting a higher probability of refuge emergence, fish treated with cortisol combined with RU486 behaved similarly to cortisol-treated and control groups. While these results suggest that cortisol may not be involved in the mechanisms controlling boldness, the influence of cortisol elevation across longer time periods plus validation in different contexts will be necessary to confirm this conclusion.
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Affiliation(s)
- Annaïs Carbajal
- Department of Animal Health and Anatomy, Veterinary Faculty, UniversitatAutònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain.
| | - Michael J Lawrence
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, Canada
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada
| | | | - Manel Lopez-Bejar
- Department of Animal Health and Anatomy, Veterinary Faculty, UniversitatAutònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain
- College of Veterinary Medicine, Western University of Health Sciences, Pomona, CA, USA
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, Canada
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McCallum ES, Cerveny D, Bose APH, Fick J, Brodin T. Cost-Effective Pharmaceutical Implants in Fish: Validating the Performance of Slow-Release Implants for the Antidepressant Fluoxetine. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:1326-1336. [PMID: 36942382 DOI: 10.1002/etc.5613] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/28/2023] [Accepted: 03/16/2023] [Indexed: 05/27/2023]
Abstract
Internal, slow-release implants can be an effective way to manipulate animal physiology or deliver a chemical exposure over long periods of time without the need for an exogenous exposure route. Slow-release implants involve dissolving a compound in a lipid-based carrier, which is inserted into the body of an organism. However, the release kinetics of the compound from the implant to body tissues also requires careful validation. We tested and validated a slow-release implant methodology for exposing fish to a pharmaceutical pollutant, fluoxetine. We tested two lipid-based carriers (coconut oil or vegetable shortening) in the common roach (Rutilus rutilus). The implants contained either a high (50 μg/g), low (25 μg/g), or control (0 μg/g) concentration of fluoxetine, and we measured tissue uptake in the brain, muscle, and plasma of implanted fish over 25 days. The two carriers released fluoxetine differently over time: coconut oil released fluoxetine in an accelerating manner (tissue uptake displayed a positive quadratic curvature), whereas vegetable shortening released fluoxetine in a decelerating manner (a negative quadratic curvature). For both carrier types, fluoxetine was measured at the highest concentration in the brain, followed by muscle and plasma. By comparing the implant exposures with waterborne exposures in the published literature, we showed that the implants delivered an internal exposure that would be similar if fish were exposed in surface waters containing effluents. Overall, we showed that slow-release internal implants are an effective method for delivering chronic exposures of fluoxetine over at least 1-month time scales. Internal exposures can be an especially powerful experimental tool when coupled with field-based study designs to assess the impacts of pharmaceutical pollutants in complex natural environments. Environ Toxicol Chem 2023;42:1326-1336. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
- Erin S McCallum
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Daniel Cerveny
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in Ceske Budejovice, Vodnany, Czech Republic
| | - Aneesh P H Bose
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Jerker Fick
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - Tomas Brodin
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
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Patel SK, Ruhela S, Biswas S, Bhatt S, Pandav B, Mondol S. The cost of sympatry: spatio-temporal patterns in leopard dietary and physiological responses to tiger competition gradient in Rajaji Tiger Reserve, Uttarakhand, India. CONSERVATION PHYSIOLOGY 2023; 11:coad039. [PMID: 38026804 PMCID: PMC10660413 DOI: 10.1093/conphys/coad039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 03/01/2023] [Accepted: 05/17/2023] [Indexed: 12/01/2023]
Abstract
Apex predators have critical roles in maintaining the structure of ecosystem functioning by controlling intraguild subordinate populations. Such dominant-subordinate interactions involve agonistic interactions including direct or indirect impacts on the subordinates. As these indirect effects are often mediated through physiological processes, it is important to quantify such responses to better understand population parameters. We used a large carnivore intraguild system involving tiger (Panthera tigris) and leopard (Panthera pardus) to understand the dietary and physiological responses under a spatio-temporal gradient of tiger competition pressures in Rajaji Tiger Reserve (RTR) between 2015 and 2020. We conducted systematic faecal sampling in the winters of 2015 and 2020 from the park to assess diet and physiological measures. Analyses of leopard-confirmed faeces suggest a dietary-niche separation as a consequence of tiger competition. In 2020, we found an increased occurrence of large-bodied prey species without tiger competition in western-RTR. Physiological measures followed the dietary responses where leopards with large-sized prey in the diet showed higher fT3M and lower fGCM measures in western-RTR. In contrast, eastern-RTR leopards showed lower levels of fT3M and fGCM in 2020, possibly due to intense competition from tigers. Overall, these patterns strongly indicate a physiological cost of sympatry where competition with dominant tigers resulted in elevated nutritional stress. We recommend expansion of leopard monitoring and population estimation efforts to buffers, developing appropriate plans for human-leopard conflict mitigation and intensive efforts to understand leopard population dynamics patterns to ensure their persistence during the ongoing Anthropocene.
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Affiliation(s)
- Shiv Kumari Patel
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001, India
| | - Sourabh Ruhela
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001, India
| | - Suvankar Biswas
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001, India
| | - Supriya Bhatt
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001, India
| | - Bivash Pandav
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001, India
| | - Samrat Mondol
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001, India
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Mahr K, Anzengruber M, Hellerschmid A, Slezacek J, Hoi H, Subbiahdoss G, Gabor F, Lendvai ÁZ. Biocompatible polymeric microparticles serve as novel and reliable vehicles for exogenous hormone manipulations in passerines. Gen Comp Endocrinol 2023; 336:114234. [PMID: 36791824 DOI: 10.1016/j.ygcen.2023.114234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 02/02/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
The administration of exogenous hormones emerged as an essential tool for field studies in endocrinology. However, working with wild animals remains challenging, because under field conditions not every available method meets the necessary requirements. Achieving a sustained elevation in hormone levels, while simultaneously minimising handling time and invasiveness of the procedure is a difficult task in field endocrinology. Facing this challenge, we have investigated the suitability of biocompatible polymeric microparticles, a novel method for drug-administration, as a tool to manipulate hormones in small songbirds. We chose the insulin-like growth factor-1 (IGF-1) as target hormone, because it receives great interest from the research community due to its important role in shaping life-history traits. Moreover, its short half-life and hydrophilic properties imply a major challenge in finding a suitable method to achieve a sustained, systemic long-term release. To study the release kinetics, we injected either IGF-1 loaded polylactic-co-glycolic acid (PLGA) microparticles or dispersion medium (control group) in the skin pocket of the interscapular region of captive bearded reedlings (Panurus biarmicus). We collected blood samples for 7 consecutive days plus an additional sampling period after two weeks and complemented these with an in vitro experiment. Our results show that in vitro, PLGA microparticles allowed a stable IGF-1 release for more than 15 days, following a burst release at the beginning of the measurement. In vivo, the initial burst was followed by a drop to still elevated levels in circulating IGF-1 until the effect vanished by 16 days post-treatment. This study is the first to describe the use of PLGA-microparticles as a novel tool for exogenous hormone administration in a small passerine. We suggest that this method is highly suitable to achieve the systemic long-term release of hydrophilic hormones with short half-life and reduces overall handling time, as it requires only one subcutaneous injection.
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Affiliation(s)
- Katharina Mahr
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria.
| | - Maria Anzengruber
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Austria
| | - Anna Hellerschmid
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Julia Slezacek
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Herbert Hoi
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Guruprakash Subbiahdoss
- Institute of Biologically Inspired Materials, Department of Nanobiotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Franz Gabor
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Austria
| | - Ádám Z Lendvai
- Department of Evolutionary Zoology and Human Biology, University of Debrecen, 4032 Debrecen, Hungary
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Different Types of Glucocorticoids to Evaluate Stress and Welfare in Animals and Humans: General Concepts and Examples of Combined Use. Metabolites 2023; 13:metabo13010106. [PMID: 36677031 PMCID: PMC9865266 DOI: 10.3390/metabo13010106] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/23/2022] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
The main glucocorticoids involved in the stress response are cortisol and cortisone in most mammals and corticosterone in birds and rodents. Therefore, these analytes are currently the biomarkers more frequently used to evaluate the physiological response to a stressful situation. In addition, "total glucocorticoids", which refers to the quantification of various glucocorticoids by immunoassays showing cross-reactivity with different types of glucocorticoids or related metabolites, can be measured. In this review, we describe the characteristics of the main glucocorticoids used to assess stress, as well as the main techniques and samples used for their quantification. In addition, we analyse the studies where at least two of the main glucocorticoids were measured in combination. Overall, this review points out the different behaviours of the main glucocorticoids, depending on the animal species and stressful stimuli, and shows the potential advantages that the measurement of at least two different glucocorticoid types can have for evaluating welfare.
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Lennox RJ, Dahlmo LS, Ford AT, Sortland LK, Vogel EF, Vollset KW. Predation research with electronic tagging. WILDLIFE BIOLOGY 2022. [DOI: 10.1002/wlb3.01045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Robert J. Lennox
- Norwegian Inst. for Nature Research Trondheim Norway
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries Bergen Norway
| | - Lotte S. Dahlmo
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries Bergen Norway
- Dept of Biological Sciences, Univ. of Bergen Bergen Norway
| | - Adam T. Ford
- Univ. of British Columbia Okanagan Kelowna BC Canada
| | - Lene K. Sortland
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries Bergen Norway
- Dept of Biological Sciences, Univ. of Bergen Bergen Norway
| | - Emma F. Vogel
- UiT − The Arctic Univ. of Norway, Faculty of Biosciences, Fisheries and Economics Tromsø Norway
| | - Knut Wiik Vollset
- NORCE Norwegian Research Centre, Laboratory for Freshwater Ecology and Inland Fisheries Bergen Norway
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Falco F, Bottari T, Ragonese S, Killen SS. Towards the integration of ecophysiology with fisheries stock assessment for conservation policy and evaluating the status of the Mediterranean Sea. CONSERVATION PHYSIOLOGY 2022; 10:coac008. [PMID: 35783348 PMCID: PMC9245081 DOI: 10.1093/conphys/coac008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 01/19/2022] [Accepted: 02/09/2022] [Indexed: 06/15/2023]
Abstract
Recent European Union (EU) regulations have been introduced to discourage the capture of undersized specimens with the aim of reducing the bycatch mortality imposed by commercial fisheries. We argue that we still lack accurate data regarding basic information required to properly implement these regulations for most Mediterranean ecosystems, including the true mortality imposed by fisheries, escape rates from fishing gears and the capability of specimens to survive following discard. We suggest that additional reliance on physiological biomarkers could assist in all aspects of the data collection required to support implementation of the EU discard ban (aka landing obligation), particularly in determining which species should receive special dispensation from this policy. Ideally, this new approach, here termed the 'Fisheries Environmental and Physiological Stress Analysis' (FEPSA), would become an important step for any fish stock assessment within the ecosystem approach to fisheries management and the recognition of Good Environmental Status, as established by the EU in the Marine Strategy Framework Directive (2008/56/EC). In particular, the main goal of FEPSA would be applying the study of physiological stressors to exploited stocks to estimate the so-called collateral fishing mortality, which includes the mortality experienced by fish that escape after interacting with fishing gears or that are discarded, with some degree of injury or physiological stress. The approach outlined here, which is described for bottom trawls but adaptable to any other type of fishing gear, is not a trivial undertaking but is a requirement for collecting the data required by recent EU fisheries policies. While we agree that the threats to marine biodiversity posed by fishing and associated discard practices require strong policy interventions, we emphasize that the research programs needed to support such initiatives, including the landing obligation, should be given equal priority. This is particularly true for Mediterranean fisheries, which are at a complex intersection of jurisdictional boundaries, numerous additional ecosystem threats including widespread pollution, thermal variation and hypoxia, and are historically understudied as compared to fisheries and species in more northern climates.
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Affiliation(s)
- F Falco
- Corresponding author: Institute of Biological Resource and Marine
Biotechnology (IRBIM), National Research Council (CNR), Section of Mazara del vallo, Via
L. Vaccara, 61 91026, TP, Italy.
| | - T Bottari
- Institute for Marine Biological Resources and Biotechnology
(IRBIM), National Research Council (CNR), Section of Messina, 98122
Messina, Italy
| | - S Ragonese
- Institute of Biological Resource and Marine Biotechnology (IRBIM), National
Research Council (CNR), Section of Mazara del vallo, Via L. Vaccara, 61
91026, TP, Italy
| | - S S Killen
- Institute of Biodiversity, Animal Health and Comparative Medicine,
University of Glasgow, Glasgow, G12 8QQ, UK
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MacLeod KJ, While GM, Uller T. Viviparous mothers impose stronger glucocorticoid-mediated maternal stress effects on their offspring than oviparous mothers. Ecol Evol 2021; 11:17238-17259. [PMID: 34938505 PMCID: PMC8668768 DOI: 10.1002/ece3.8360] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/20/2021] [Accepted: 10/29/2021] [Indexed: 01/07/2023] Open
Abstract
Maternal stress during gestation has the potential to affect offspring development via changes in maternal physiology, such as increases in circulating levels of glucocorticoid hormones that are typical after exposure to a stressor. While the effects of elevated maternal glucocorticoids on offspring phenotype (i.e., "glucocorticoid-mediated maternal effects") have been relatively well established in laboratory studies, it remains poorly understood how strong and consistent such effects are in natural populations. Using a meta-analysis of studies of wild mammals, birds, and reptiles, we investigate the evidence for effects of elevated maternal glucocorticoids on offspring phenotype and investigate key moderators that might influence the strength and direction of these effects. In particular, we investigate the potential importance of reproductive mode (viviparity vs. oviparity). We show that glucocorticoid-mediated maternal effects are stronger, and likely more deleterious, in mammals and viviparous squamate reptiles compared with birds, turtles, and oviparous squamates. No other moderators (timing and type of manipulation, age at offspring measurement, or type of trait measured) were significant predictors of the strength or direction of the phenotypic effects on offspring. These results provide evidence that the evolution of a prolonged physiological association between embryo and mother sets the stage for maladaptive, or adaptive, prenatal stress effects in vertebrates driven by glucocorticoid elevation.
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Heterothermy as a mechanism to offset energetic costs of environmental and homeostatic perturbations. Sci Rep 2021; 11:19038. [PMID: 34561468 PMCID: PMC8463709 DOI: 10.1038/s41598-021-96828-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 08/05/2021] [Indexed: 11/30/2022] Open
Abstract
Environmental and biotic pressures impose homeostatic costs on all organisms. The energetic costs of maintaining high body temperatures (Tb) render endotherms sensitive to pressures that increase foraging costs. In response, some mammals become more heterothermic to conserve energy. We measured Tb in banner-tailed kangaroo rats (Dipodomys spectabilis) to test and disentangle the effects of air temperature and moonlight (a proxy for predation risk) on thermoregulatory homeostasis. We further perturbed homeostasis in some animals with chronic corticosterone (CORT) via silastic implants. Heterothermy increased across summer, consistent with the predicted effect of lunar illumination (and predation), and in the direction opposite to the predicted effect of environmental temperatures. The effect of lunar illumination was also evident within nights as animals maintained low Tb when the moon was above the horizon. The pattern was accentuated in CORT-treated animals, suggesting they adopted an even further heightened risk-avoidance strategy that might impose reduced foraging and energy intake. Still, CORT-treatment did not affect body condition over the entire study, indicating kangaroo rats offset decreases in energy intake through energy savings associated with heterothermy. Environmental conditions receive the most attention in studies of thermoregulatory homeostasis, but we demonstrated here that biotic factors can be more important and should be considered in future studies.
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Health Status and Stress in Different Categories of Racing Pigeons. Animals (Basel) 2021; 11:ani11092686. [PMID: 34573652 PMCID: PMC8470826 DOI: 10.3390/ani11092686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Corticosterone is the most important “stress” hormone in birds. Stress response is influenced by different factors, such as phylogeny, feed supply, age, body condition, health status, climate, predators. Pigeon races over long distances, 500 km or more, can lead to the “exploitation” of animals if not strictly regulated and observed, jeopardizing their welfare status. Animals should be in good health and body condition, and health monitoring must be implemented. In stressful situations such as races, the possibility of infection increases. Clinically asymptomatic infections can flare up later in the breeding season and can cause high offspring mortality. For example, infections with circoviruses are particularly important because of their ability to weaken the immune system. The purpose of this work is to identify the critical stress points during the active training season of racing pigeons for the improvement of their condition and the preservation of their welfare during races. The aim of our study was to determine the serum corticosterone levels in different categories of racing pigeons exposed to severe stress factors. At the time of racing, some parameters of stress, including environmental factors, or the presence of infectious diseases or parasites, were recorded. It was found that participation in the race significantly increased serum corticosterone levels and remained high even one month after the race. Therefore, training and races should be properly managed and planned. Abstract The influence of different stress parameters in racing pigeon flocks, such as the presence of diseases and environmental conditions at the time of the races, were described. A total of 96 racing pigeons from 4 pigeon flocks were examined, and health monitoring was carried out. No helminth eggs and coccidia were found. Trichomonas sp. was confirmed in subclinical form. Paramyxoviruses and avian influenza viruses were not confirmed, but circovirus infections were confirmed in all flocks. Chlamydia psittaci was confirmed in one flock. Blood samples were collected, and HI antibody titers against paramyxoviruses before and 25 days after vaccination were determined. To improve the conditions during racing and the welfare of the pigeons, critical points were studied with regard to stress factors during the active training season. Serum corticosterone levels were measured in the blood serum of four different categories of pigeons from each flock. Corticosterone levels were almost twice as high in pigeons from the category that were active throughout the racing season, including medium- and long-distance racing, compared to the other three categories that were not racing actively. Within five hours of the finish of a race, the average serum corticosterone level was 59.4 nmol/L in the most physically active category. The average serum corticosterone level in this category remained at 37.5 nmol/L one month after the last race.
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Kumari Patel S, Biswas S, Goswami S, Bhatt S, Pandav B, Mondol S. Effects of faecal inorganic content variability on quantifying glucocorticoid and thyroid hormone metabolites in large felines: Implications for physiological assessments in free-ranging animals. Gen Comp Endocrinol 2021; 310:113833. [PMID: 34089705 DOI: 10.1016/j.ygcen.2021.113833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 05/16/2021] [Accepted: 06/01/2021] [Indexed: 11/22/2022]
Abstract
Faecal glucocorticoid (GC) and triiodothyronine (T3) metabolites and their interactions are increasingly used to monitor perceived stress and nutritional challenges in free-ranging animals. However, a number of extrinsic and intrinsic factors including hormone-inert dietary materials, inorganic matters etc. are known to affect reliable hormone metabolite quantifications. In this study, the impacts of inorganic matter (IOM) on faecal GC (fGCMs) and T3 (fT3Ms) metabolite measure were addressed in wild tiger (n = 193 from Terai Arc landscape, India) and captive lion (n = 120 from Sakkarbaug Zoological Garden, Gujarat, India) and possible corrective measures were evaluated. The wild tiger samples contained highly variable IOM content (9-98%, mostly with > 40% IOM) compared to captive Asiatic lion (17-57%, majority with < 40% IOM). Significant correlations were observed between IOM content and tiger fGCM (r = -0.46, p = 0.000), fT3M (r = -0.58, p = 0.000) and lion fT3M measures (r = -0.43, p = 0.003). Two corrective measures viz. removing samples with ≥ 80% IOM and subsequently expressing concentrations as per gram of organic dry matter (instead of total dry matter) reduced IOM influence on tiger fGCM, fT3M and lion fT3M, without affecting lion fGCM measures. The corrective measures changed the interpretations of fT3M data of field-collected tiger samples with no significant changes in fGCM (both tiger and lion) and fT3M (lion) data. As faecal IOM content is common in many wild species, the results emphasize the need to reduce IOM-driven hormone data variation for ecologically relevant interpretations towards species conservation.
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Affiliation(s)
- Shiv Kumari Patel
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001 India
| | - Suvankar Biswas
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001 India
| | - Sitendu Goswami
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001 India
| | - Supriya Bhatt
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001 India
| | - Bivash Pandav
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001 India
| | - Samrat Mondol
- Wildlife Institute of India, Chandrabani, Dehradun, Uttarakhand 248001 India.
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Shidemantle G, Buss N, Hua J. Are glucocorticoids good indicators of disturbance across populations that exhibit cryptic variation in contaminant tolerance? Anim Conserv 2021. [DOI: 10.1111/acv.12737] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- G. Shidemantle
- Biological Sciences Department Binghamton University (SUNY) Binghamton NY USA
| | - N. Buss
- Biological Sciences Department Binghamton University (SUNY) Binghamton NY USA
| | - J. Hua
- Biological Sciences Department Binghamton University (SUNY) Binghamton NY USA
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14
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Combined Effects of Experimentally Elevated CORT and Predation Threat on Exploratory and Foraging Behavior of Desmognathus ochrophaeus. J HERPETOL 2021. [DOI: 10.1670/20-077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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15
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Baugh AT, Gall MD, Silver SC, Bee MA. Moderately elevated glucocorticoids increase mate choosiness but do not affect sexual proceptivity or preferences in female gray treefrogs. Horm Behav 2021; 130:104950. [PMID: 33556376 DOI: 10.1016/j.yhbeh.2021.104950] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 01/15/2021] [Accepted: 01/30/2021] [Indexed: 01/20/2023]
Abstract
Glucocorticoids (GCs) are rarely studied in the context of female mate choice, despite the expression of receptors for these products in sexual, sensory and decision-making brain areas. Here we investigated the effects of GC concentrations on three aspects of female sexual behavior in breeding Cope's gray treefrogs (Hyla chrysoscelis): proceptivity-a measure of sexual motivation, intraspecific mate preferences, and mate choosiness. To our knowledge this is the first experimental study on the endocrine basis of mate choosiness. We predicted that mate choosiness-forfeiting an initial mate preference to pursue a suddenly more attractive mate-would be particularly impacted by elevated GCs with moderate GC levels associated with greater choosiness. We found support for this predicted inverted-U relationship. Females in the control group (no injection) showed no change in choosiness across timepoints. In contrast, females in the vehicle, Low (20 ng g-1) and High (180 ng g-1) corticosterone groups exhibited a nominal decline in choosiness after injection, suggesting that the experience of injection has little or perhaps slightly suppressive effects on female choosiness. Females in the moderate dose group (60 ng g-1), however, exhibited a significant increase (>100%) in choosiness. Further, we found no effect of elevated GCs on sexual proceptivity or the species-typical preference for longer calls. These findings may reflect a buffering of primary sensory areas in the brain against elevated GCs. The recruitment of other cognitive processes during active decision-making, however, may facilitate GC modulation of mate choosiness, thereby promoting tactical plasticity at this critical life history juncture.
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Affiliation(s)
- Alexander T Baugh
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA.
| | - Megan D Gall
- Department of Biology, Vassar College, 124 Raymond Ave., Poughkeepsie, NY 12604, USA
| | - Stewart C Silver
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
| | - Mark A Bee
- Department of Ecology, Evolution, and Behavior, University of Minnesota - Twin Cities, 1479 Gortner Ave, St. Paul, MN 55108, USA; Graduate Program in Neuroscience, University of Minnesota - Twin Cities, 321 Church Street SE, Minneapolis, MN 55455, USA
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16
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Boyle SA, de la Sancha NU, Pérez P, Kabelik D. Small mammal glucocorticoid concentrations vary with forest fragment size, trap type, and mammal taxa in the Interior Atlantic Forest. Sci Rep 2021; 11:2111. [PMID: 33542277 PMCID: PMC7862606 DOI: 10.1038/s41598-021-81073-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/29/2020] [Indexed: 12/14/2022] Open
Abstract
Species that live in degraded habitats often show signs of physiological stress. Glucocorticoid hormones (e.g., corticosterone and cortisol) are often assessed as a proxy of the extent of physiological stress an animal has experienced. Our goal was to quantify glucocorticoids in free-ranging small mammals in fragments of Interior Atlantic Forest. We extracted glucocorticoids from fur samples of 106 small mammals (rodent genera Akodon and Oligoryzomys, and marsupial genera Gracilinanus and Marmosa) from six forest fragments (2–1200 ha) in the Reserva Natural Tapytá, Caazapá Department, Paraguay. To our knowledge, this is the first publication of corticosterone and cortisol levels for three of the four sampled genera (Akodon, Oligoryzomys, and Marmosa) in this forest system. We discovered three notable results. First, as predicted, glucocorticoid levels were higher in individuals living withing small forest fragments. Second, animals captured live using restraint trapping methods (Sherman traps) had higher glucocorticoid levels than those animals captured using kill traps (Victor traps), suggesting that hair glucocorticoid measures can reflect acute stress levels in addition to long-term glucocorticoid incorporation. These acute levels are likely due to urinary steroids diffusing into the hair shaft. This finding raises a concern about the use of certain trapping techniques in association with fur hormone analysis. Finally, as expected, we also detected genus-specific differences in glucocorticoid levels, as well as cortisol/corticosterone ratios.
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Affiliation(s)
- Sarah A Boyle
- Department of Biology and Program in Environmental Studies and Sciences, Rhodes College, Memphis, TN, USA.
| | - Noé U de la Sancha
- Department of Biological Sciences, Chicago State University, Chicago, IL, USA.,The Field Museum, Integrative Research Center, Chicago, IL, USA
| | - Pastor Pérez
- Facultad Politécnica, Universidad Nacional de Asunción, Asunción, Paraguay
| | - David Kabelik
- Department of Biology and Program in Neuroscience, Rhodes College, Memphis, TN, USA
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17
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Schoenle LA, Zimmer C, Miller ET, Vitousek MN. Does variation in glucocorticoid concentrations predict fitness? A phylogenetic meta-analysis. Gen Comp Endocrinol 2021; 300:113611. [PMID: 32950580 DOI: 10.1016/j.ygcen.2020.113611] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 07/07/2020] [Accepted: 09/09/2020] [Indexed: 12/18/2022]
Abstract
Glucocorticoid hormones (GCs) are central mediators of metabolism and the response to challenges. Because circulating GC levels increase in response to challenges, within-population variation in GCs could reflect among-individual variation in condition or experience. At the same time, individual variation in GC regulation could have causal effects on energetic balance or stress coping capacity in ways that influence fitness. Although a number of studies in vertebrates have tested whether variation in GCs among individuals predicts components of fitness, it is not clear whether there are consistent patterns across taxa. Here we present the first phylogenetic meta-analysis testing whether variation in GCs is associated with survival and reproductive success across vertebrates. At the same time, we introduce and test predictions about a potentially important mediator of GC-fitness relationships: life history context. We suggest that strong context-dependence in the fitness benefit of maintaining elevated GCs could obscure consistent patterns between GCs and fitness across taxa. Meta-analyses revealed that baseline and stress-induced GCs were consistently negatively correlated with reproductive success. This relationship did not differ depending on life history context. In contrast, the relationships between GCs and survival were highly context dependent, differing according to life history strategy. Both baseline and stress-induced GCs were more strongly negatively associated with survival in longer-lived populations and species. Stress-induced GCs were also more positively associated with survival in organisms that engage in relatively more valuable reproductive attempts. Fecal GCs did not correlate with survival or reproductive success. We also found that experimental increases in GCs reduced both survival and reproductive success; however, evidence of publication bias and the small sample size suggest that more data is required to confirm this conclusion. Overall, these results support the prediction that GC-fitness relationships can be strongly context dependent, and suggest that incorporating life history may be particularly important for understanding GC-survival relationships.
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Affiliation(s)
- Laura A Schoenle
- Office of Undergraduate Biology, Cornell University, Ithaca, NY 14853, USA.
| | - Cedric Zimmer
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | | | - Maren N Vitousek
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA; Cornell Lab of Ornithology, Ithaca NY 14850, USA
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18
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Siroski PA, María Soledad MB. Review of the Recent Knowledge on the Crocodilian Immune System. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2020. [DOI: 10.2994/sajh-d-19-00093.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Pablo A. Siroski
- Laboratorio de Zoología Aplicada: Anexo Vertebrados, Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral, Ministerio de Medio Ambiente y Cambio Climático, Santa Fe, Argentina
| | - Moleón Barsani María Soledad
- Laboratorio de Zoología Aplicada: Anexo Vertebrados, Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral, Ministerio de Medio Ambiente y Cambio Climático, Santa Fe, Argentina
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19
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Gingery TM, Diefenbach DR, Pritchard CE, Ensminger DC, Wallingford BD, Rosenberry CS. Survival is negatively associated with glucocorticoids in a wild ungulate neonate. Integr Zool 2020; 16:214-225. [PMID: 33164347 DOI: 10.1111/1749-4877.12499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
It is unknown how ungulate physiological responses to environmental perturbation influence overall population demographics. Moreover, neonatal physiological responses remain poorly studied despite the importance of neonatal survival to population growth. Glucocorticoid (GC) hormones potentially facilitate critical physiological and behavioral responses to environmental perturbations. However, elevated GC concentrations over time may compromise body condition and indirectly reduce survival. We evaluated baseline salivary cortisol (CORT; a primary GC in mammals) concentrations in 19 wild neonatal white-tailed deer (Odocoileus virginianus) in a northern (NS) and southern (SS) area in Pennsylvania. After ranking survival models consisting of variables hypothesized to influence neonate survival (i.e. weight, sex), the probability of neonate survival was best explained by CORT concentrations, where elevated CORT concentrations were associated with reduced survival probability to 12 weeks of age. Cortisol concentrations were greater in the SS where predation rates and predator densities were lower. As the first evaluation of baseline CORT concentrations in an ungulate neonate to our knowledge, this is also the first study to demonstrate CORT concentrations are negatively associated with ungulate survival at any life stage. Glucocorticoid hormones could provide a framework in which to better understand susceptibility to mortality in neonatal white-tailed deer.
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Affiliation(s)
- Tess Michelle Gingery
- Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Duane Richard Diefenbach
- Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania, USA.,U. S. Geological Survey, Pennsylvania Cooperative Fish and Wildlife Research Unit, Pennsylvania State University, University Park, Pennsylvania, USA
| | | | - David Charles Ensminger
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania, USA
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20
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An Investigation of the Effect of Catecholamines and Glucocorticoids on the Growth and Pathogenicity of Campylobacter jejuni. Pathogens 2020; 9:pathogens9070555. [PMID: 32664224 PMCID: PMC7400237 DOI: 10.3390/pathogens9070555] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/03/2020] [Accepted: 07/05/2020] [Indexed: 12/28/2022] Open
Abstract
Campylobacter spp. are major causes of foodborne illness globally, and are mostly transmitted through the consumption and handling of poultry. Campylobacter infections have widely variable outcomes, ranging from mild enteritis to severe illness, which are attributed to host interactions and the virulence of the infecting strain. In this study, in order to investigate the effect of host stress on the growth and pathogenicity of C. jejuni, three strains associated with human infection and two strains from broilers were subject to growth, motility, adhesion and invasion assays, in response to exposure to catecholamines; epinephrine, norepinephrine and the glucocorticoid neuroendocrine hormones corticosterone, cortisol and cortisone which are associated with stress in humans and broilers. Catecholamines resulted in significantly increased growth, adhesion and invasion of Caco-2 cells. Corticosterone promoted growth in one of five strains, and cortisone resulted in a significant increase in motility in two out of five strains, while no significant differences were observed with the addition of cortisol. It was concluded that stress-associated hormones, especially catecholamines, may promote growth and virulence in Campylobacter.
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21
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Mingramm FMJ, Keeley T, Whitworth DJ, Dunlop RA. Blubber cortisol levels in humpback whales (Megaptera novaeangliae): A measure of physiological stress without effects from sampling. Gen Comp Endocrinol 2020; 291:113436. [PMID: 32057910 DOI: 10.1016/j.ygcen.2020.113436] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 02/01/2020] [Accepted: 02/10/2020] [Indexed: 11/19/2022]
Abstract
Baleen whales are vulnerable to environmental impacts due to low fecundity, capital breeding strategies, and their reliance on a large amount of prey resources over large spatial scales. There has been growing interest in monitoring health and physiological stress in these species but, to date, few measures have been validated. The purpose of this study was to examine whether blubber cortisol could be used as a measure of physiological stress in humpback whales. Cortisol concentrations were initially compared between live, presumably 'healthy' whales (n = 187) and deceased whales (n = 35), which had died after stranding or entanglement, or washed ashore as a carcass. Deceased whales were found to have significantly higher cortisol levels (mean ± SD; 5.47 ± 4.52 ng/g) than live whales (0.51 ± 0.14 ng/g; p < 0.001), particularly for those animals that had experienced prolonged trauma (e.g. stranding) prior to death. Blubber cortisol levels in live whales were then examined for evidence of life history-related, seasonal, or sampling-related effects. Life history group and sampling-related factors, such as encounter time and the number of biopsy sampling attempts per animal, were found to be poor predictors of blubber cortisol levels in live whales. In contrast, blubber cortisol levels varied seasonally, with whales migrating north towards the breeding grounds in winter having significantly higher levels (0.54 ± 0.21 ng/g, p = 0.016) than those migrating south towards the feeding grounds in spring (0.48 ± 1.23 ng/g). These differences could be due to additional socio-physiological stress experienced by whales during peaks in breeding activity. Overall, blubber cortisol appears to be a suitable measure of chronic physiological stress in humpback whales.
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Affiliation(s)
- Fletcher M J Mingramm
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia; Wildlife Endocrinology Lab, School of Agriculture and Food Science, The University of Queensland, Gatton, QLD 4343, Australia.
| | - Tamara Keeley
- Wildlife Endocrinology Lab, School of Agriculture and Food Science, The University of Queensland, Gatton, QLD 4343, Australia
| | - Deanne J Whitworth
- School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia; Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Rebecca A Dunlop
- Cetacean Ecology and Acoustics Laboratory, School of Veterinary Science, The University of Queensland, Gatton, QLD 4343, Australia
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22
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Schoenle LA, Moore IT, Dudek AM, Garcia EB, Mays M, Haussmann MF, Cimini D, Bonier F. Exogenous glucocorticoids amplify the costs of infection by reducing resistance and tolerance, but effects are mitigated by co-infection. Proc Biol Sci 2020; 286:20182913. [PMID: 30966992 DOI: 10.1098/rspb.2018.2913] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Individual variation in parasite defences, such as resistance and tolerance, can underlie heterogeneity in fitness and could influence disease transmission dynamics. Glucocorticoid hormone concentrations often change in response to fluctuating environmental conditions and mediate changes in immune function, resource allocation and tissue repair. Thus, changes in glucocorticoid hormone concentrations might mediate individual variation in investment in resistance versus tolerance. In this study, we experimentally increased glucocorticoid concentrations in red-winged blackbirds ( Agelaius phoeniceus) that were naturally infected with haemosporidian parasites, and assessed changes in resistance and tolerance of infection. Glucocorticoid treatment increased burdens of Plasmodium, the parasite causing avian malaria, but only in the absence of co-infection with another Haemosporidian, Haemoproteus. Thus, glucocorticoids might reduce resistance to infection, but co-infection can mitigate the negative consequences of increased hormone concentrations. Glucocorticoid treatment also decreased tolerance of infection. We found no evidence that the inflammatory immune response or rate of red blood cell production underlie the effects of glucocorticoids on resistance and tolerance. Our findings suggest that exogenous glucocorticoids can increase the costs of haemosporidian infections by both increasing parasite numbers and reducing an individual's ability to cope with infection. These effects could scale up to impact populations of both host and parasite.
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Affiliation(s)
- Laura A Schoenle
- 1 Office of Undergraduate Biology, Cornell University , Ithaca, NY , USA.,2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Ignacio T Moore
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Alana M Dudek
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Ellen B Garcia
- 3 Department of Biological Sciences and Biocomplexity Institute, Virginia Tech , Blacksburg, VA , USA
| | - Morgan Mays
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA
| | - Mark F Haussmann
- 4 Department of Biology, Bucknell University , Lewisburg, PA , USA
| | - Daniela Cimini
- 3 Department of Biological Sciences and Biocomplexity Institute, Virginia Tech , Blacksburg, VA , USA
| | - Frances Bonier
- 2 Department of Biological Sciences, Virginia Tech , Blacksburg, VA , USA.,5 Biology Department, Queen's University , Kingston, Ontario , Canada
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23
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van Kesteren F, Delehanty B, Westrick SE, Palme R, Boonstra R, Lane JE, Boutin S, McAdam AG, Dantzer B. Experimental Increases in Glucocorticoids Alter Function of the HPA Axis in Wild Red Squirrels without Negatively Impacting Survival and Reproduction. Physiol Biochem Zool 2020; 92:445-458. [PMID: 31365306 DOI: 10.1086/705121] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hormones such as glucocorticoids (colloquially referred to as "stress hormones") have important effects on animal behavior and life-history traits, yet most of this understanding has come through correlative studies. While experimental studies offer the ability to assign causality, there are important methodological concerns that are often not considered when manipulating hormones, including glucocorticoids, in wild animals. In this study, we examined how experimental elevations of cortisol concentrations in wild North American red squirrels (Tamiasciurus hudsonicus) affected their hypothalamic-pituitary-adrenal (HPA) axis reactivity and life-history traits, including body mass, litter survival, and adult survival. The effects of exogenous cortisol on plasma cortisol concentrations depended on the time between treatment consumption and blood sampling. In the first 9 h after consumption of exogenous cortisol, individuals had significantly higher true baseline plasma cortisol concentrations, but adrenal gland function was impaired as indicated by their dampened response to capture and handling and to injections of adrenocorticotropic hormone compared to controls. Approximately 24 h after consumption of exogenous cortisol, individuals had much lower plasma cortisol concentrations than controls, but adrenal function was restored. Corticosteroid-binding globulin (CBG) concentrations were also significantly reduced in squirrels treated with cortisol. Despite these profound shifts in the functionality of the HPA axis, squirrel body mass, offspring survival, and adult survival were unaffected by experimental increases in cortisol concentrations. Our results highlight that even short-term experimental increases in glucocorticoids can affect adrenal gland functioning and CBG concentrations but without other side effects.
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24
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Lewis JL, Sullivan AM. Salamander stress and duress: the relationship between CORT, autotomy and regeneration, and exploratory behaviour. ZOOLOGY 2020; 139:125751. [PMID: 32070799 DOI: 10.1016/j.zool.2020.125751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 01/23/2023]
Abstract
Responses to stress are generally mediated through the production of glucocorticoids by the hypothalamic-pituitary-adrenal (or -interrenal) axis. The prolonged production of stress hormones can contribute to delayed wound healing and growth, but little is known about their influence on regeneration following tail autotomy, or exploratory behaviour in autotomized individuals. Here we examined the relationship between stress, regeneration, and exploratory behaviour in Allegheny Mountain dusky salamanders (Desmognathus ochrophaeus) by manipulating corticosterone (CORT) levels via cutaneous patch. First, we measured tail regeneration in salamanders with elevated CORT for 13 weeks after the induction of tail autotomy. Test subjects received a weekly patch to wear for one hour that was saturated with either a low CORT (0.25 mg/ml) or high CORT (0.50 mg/ml) solution. Individuals receiving CORT patches regenerated significantly less of their tail length and volume (versus control), but without exhibiting dose-dependent effects. Second, we used a factorial design to evaluate the effects of autotomy and elevated CORT on exploration within a test arena consisting of low barriers arrayed in concentric rings. Individuals experiencing tail autotomy exhibited significantly less exploratory behaviour indicated by an increased latency to cross first barrier and a decreased number of barriers crossed. Neither elevated CORT (0.50 mg/ml), nor the interaction between elevated CORT and tail autotomy significantly affected salamander activity within the array. Although CORT did not have a direct effect on explorative behaviour, a delay in regeneration attributed to CORT could lead to changes in patterns of movement in autotomized individuals.
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Affiliation(s)
- Jacquelyn L Lewis
- Department of Biology, Houghton College, Houghton, NY 14744, USA; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Aaron M Sullivan
- Department of Biology, Houghton College, Houghton, NY 14744, USA
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25
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Bonier F, Cox RM. Do hormone manipulations reduce fitness? A meta-analytic test of the Optimal Endocrine Phenotype Hypothesis. Mol Cell Endocrinol 2020; 500:110640. [PMID: 31715223 DOI: 10.1016/j.mce.2019.110640] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 11/03/2019] [Accepted: 11/05/2019] [Indexed: 11/21/2022]
Abstract
Endocrine traits (e.g., circulating hormone concentrations, receptor expression) can vary considerably among individuals within populations. Here, we develop two evolutionary hypotheses to explain this variation. Under the Optimal Endocrine Phenotype Hypothesis, adaptive plastic responses to environmental variation generate individual variation in endocrine traits and allow individuals to express near-optimal endocrine phenotypes. In contrast, under the Ongoing Selection Hypothesis, individual variation in endocrine traits reflects varying adaptive value, with some individuals expressing suboptimal phenotypes that are selected against. These two hypotheses generate distinct predictions for the effects of hormone manipulations on fitness. Under the Optimal Endocrine Phenotype Hypothesis, all hormone manipulations should incur fitness costs, whereas under the Ongoing Selection Hypothesis, manipulating endocrine phenotypes toward a putative optimum should increase fitness. Using a meta-analysis of findings from experimental field studies that involved manipulation of circulating glucocorticoids or androgens and measurement of fitness effects, we test and find some support for the Optimal Endocrine Phenotype Hypothesis. On average, fitness was reduced across 97 estimates of the effects of experimental hormone manipulations on fitness. However, the fitness effects of glucocorticoid manipulations varied with the sex of the individuals being studied. Fitness was more uniformly reduced by glucocorticoid manipulations in males and when both sexes were considered together. In females, effects on fitness varied from highly positive to highly negative. The effects of androgen manipulations varied across males and females, and depending upon whether fitness was estimated using measures of reproductive success or survival. Reproductive success was consistently decreased by androgen manipulation in females, but was increased almost as often as it was decreased across experiments in males. When survival was estimated as a component of fitness, it was fairly uniformly compromised by exogenous androgens in males. This variation in fitness effects of hormone manipulations across sexes and fitness metrics is consistent with the expectation that hormones differentially regulate life-history investment and that optimal endocrine phenotypes differ between males and females. Overall, our meta-analysis provides some support for the Optimal Endocrine Phenotype Hypothesis, but we await direct tests of the Ongoing Selection Hypothesis to determine the degree to which individual variation in endocrine traits continues to be shaped by natural selection.
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Affiliation(s)
- Frances Bonier
- Department of Biology, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
| | - Robert M Cox
- Department of Biology, University of Virginia, Charlottesville, VA, 22904, USA
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26
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Sandfoss MR, Claunch NM, Stacy NI, Romagosa CM, Lillywhite HB. A tale of two islands: evidence for impaired stress response and altered immune functions in an insular pit viper following ecological disturbance. CONSERVATION PHYSIOLOGY 2020; 8:coaa031. [PMID: 32382421 PMCID: PMC7196672 DOI: 10.1093/conphys/coaa031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 01/30/2020] [Accepted: 03/18/2020] [Indexed: 05/16/2023]
Abstract
The frequency and intensity of ecological perturbations affecting wild animal populations is expected to increase in the future with animals facing numerous global threats. Seahorse Key is a continental island off mainland Florida that has historically been a major rookery for several species of waterbirds. As a result of an unknown disturbance, the entire rookery abandoned Seahorse Key in April 2015 and shifted nesting activities to nearby Snake Key, resulting in an influx of food resources in the form of fish carrion to resident Florida cottonmouth snakes (Agkistrodon conanti), while snakes on Seahorse Key experienced a drastic reduction in food resources. Our objective was to assess plasma corticosterone concentrations, corticosterone negative feedback using dexamethasone, blood glucose, body condition, packed cell volume, natural antibody agglutination, white blood cell counts and ratios and erythrocyte sedimentation rate to characterize the long-term effects of differential resource availability in these two snake populations 3 years after this major ecological disturbance. We collected blood samples at three time points from cottonmouths on Seahorse Key (n = 6 individuals) and Snake Key (n = 13 individuals) in fall 2018. In due consideration of the small sample size, our study shows evidence that 3 years after the shift in waterbird nesting Seahorse Key cottonmouths exhibit a dampened acute stress response and presumptive impaired innate immune functions relative to cottonmouths on Snake Key. These results highlight the context-dependent nature of biomarkers and implicate the significant decrease in food resources on Seahorse Key in altering hormonal stress responses and innate immune functions, possibly leading to unknown long-term downstream effects. This study assessed the response of a wild population of pit viper to ecological disturbance in situ with the aim to improve our understanding of how animals cope with such perturbations and improve our capacity to make informed decisions for conservation.
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Affiliation(s)
- Mark R Sandfoss
- Department of Biology, University of Florida, 221 Carr Hall, Gainesville, FL, 32611, USA
- Corresponding author: University of Florida, 221 Carr Hall, Gainesville, FL 32611, USA.
| | - Natalie M Claunch
- School of Natural Resources and Environment, University of Florida, 103 Black Hall, Gainesville, FL, 32611, USA
| | - Nicole I Stacy
- Aquatic, Amphibian, and Reptile Pathology Program, Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL, 32610, USA
| | - Christina M Romagosa
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, FL, 32611, USA
| | - Harvey B Lillywhite
- Department of Biology, University of Florida, 221 Carr Hall, Gainesville, FL, 32611, USA
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27
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Lawrence MJ, Eliason EJ, Zolderdo AJ, Lapointe D, Best C, Gilmour KM, Cooke SJ. Cortisol modulates metabolism and energy mobilization in wild-caught pumpkinseed (Lepomis gibbosus). FISH PHYSIOLOGY AND BIOCHEMISTRY 2019; 45:1813-1828. [PMID: 31300974 DOI: 10.1007/s10695-019-00680-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
Acute elevation of cortisol via activation of the hypothalamic-pituitary-interrenal (HPI) axis aids the fish in dealing with a stressor. However, chronic elevation of cortisol has detrimental effects and has been studied extensively in lab settings. However, data pertaining to wild teleosts are lacking. Here, we characterized the metabolic consequences of prolonged cortisol elevation (96 h) in wild-caught pumpkinseed (Lepomis gibbosus). Pumpkinseed were implanted with cocoa butter alone (sham) or containing cortisol (25 mg kg-1 body weight), and at 24, 48, 72, and 96 h, tissue samples were collected, whole-body ammonia excretion was determined, and whole-organism metabolism was assessed using intermittent flow respirometry. Cortisol-treated pumpkinseed exhibited the highest plasma cortisol concentration at 24 h post-implantation, with levels decreasing over the subsequent time points although remaining higher than in sham-treated fish. Cortisol-treated fish exhibited higher standard and maximal metabolic rates than sham-treated fish, but the effect of cortisol treatment on aerobic scope was negligible. Indices of energy synthesis/mobilization, including blood glucose concentrations, hepatosomatic index, hepatic glycogen concentrations, and ammonia excretion rates, were higher in cortisol-treated fish compared with controls. Our work suggests that although aerobic scope was not diminished by prolonged elevation of cortisol levels, higher metabolic expenditures may be of detriment to the animal's performance in the longer term.
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Affiliation(s)
- Michael J Lawrence
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, K1S 5B6, Canada.
| | - Erika J Eliason
- Department of Ecology, Evolution & Marine Biology, University of California, Santa Barbara, CA, 93117, USA
| | - Aaron J Zolderdo
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, K1S 5B6, Canada
- Queen's University Biological Station, Queen's University, Elgin, ON, K0G 1E0, Canada
| | - Dominique Lapointe
- St. Lawrence River Institute of Environmental Sciences, Cornwall, ON, K6H 4Z1, Canada
| | - Carol Best
- Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Kathleen M Gilmour
- Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON, K1S 5B6, Canada
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Differential antipredatory responses in the tuco-tuco (Ctenomys talarum) in relation to endogenous and exogenous changes in glucocorticoids. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2019; 206:33-44. [PMID: 31784830 DOI: 10.1007/s00359-019-01384-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 10/11/2019] [Accepted: 11/19/2019] [Indexed: 10/25/2022]
Abstract
Glucocorticoids participate in the behavioral and physiological responses generated under stressful circumstances coming from different sources-physical and/or psychological. In mammals, the increases of these hormones are mediated by the activation of the hypothalamic-pituitary-adrenal axis. This response occurs after exposure to novel and unpredictable situations that lead to the loss of homeostasis, for example, a direct encounter with predators or their cues. However, the relationship between the physiological and behavioral responses is still a complex issue in vertebrates. We evaluate the effects of an experimental manipulation of glucocorticoid levels on the generation of the behavioral and physiological response to stress by predation in the subterranean rodent C. talarum. We found that when tuco-tucos encountered predator cues-fur odor, and largely, immobilization-they responded physiologically by secreting cortisol. This response was accompanied by an associated behavioral response. However, when the increase in plasma cortisol originated exogenously by the injection of cortisol, a behavioral response was not observed. Finally, inhibition of glucocorticoids' synthesis was effective in weakening the behavioral effects produced by immobilization. In conclusion, in tuco-tucos, predator cues act as stress factors that trigger differential increases in plasma cortisol and a behavioral response associated with the appearance of anxiety states.
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29
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McCallum ES, Cerveny D, Fick J, Brodin T. Slow-Release Implants for Manipulating Contaminant Exposures in Aquatic Wildlife: A New Tool for Field Ecotoxicology. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8282-8290. [PMID: 31067036 DOI: 10.1021/acs.est.9b01975] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Field-based ecotoxicology studies are invaluable for uncovering the effects of contaminants of emerging concern (CECs) on aquatic organisms. However, large-scale exposures are still very rare due to prohibitive costs, the availability of replicated habitats, and the potential for exposure to cause lasting damage to the environment. Here, we evaluated the viability of internal slow-release implants as an alternative method for manipulating CEC exposures in aquatic wildlife using two fat-based carriers (coconut oil and vegetable shortening). We treated roach (Rutilus rutilus) with implants containing a high (50 μg/g), low (25 μg/g), or control (0 μg/g) concentration of the behavior-modifying pharmaceutical oxazepam. We then measured oxazepam uptake in four tissues (plasma, muscle, liver, and the brain) over 1 month. The two carriers released oxazepam differently: coconut oil was the superior implant type because it delivered a more consistent dose across time, while vegetable shortening released oxazepam rapidly at the start of the exposure period. For both carriers and treatments, the brain and liver contained the most oxazepam. Overall, the method is a promising technique for controlled manipulations of pharmaceuticals in fish, and we have provided some of the first data on the suitability and contaminant release kinetics from different implant types.
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Affiliation(s)
- Erin S McCallum
- Department of Ecology & Environmental Science , Umeå University , SE-90187 Umeå , Sweden
- Department of Wildlife, Fish, and Environmental Studies , Swedish University of Agricultural Sciences (SLU) , SE-90183 Umeå , Sweden
| | - Daniel Cerveny
- Department of Chemistry , Umeå University , SE-90187 Umeå , Sweden
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Research Institute of Fish Culture and Hydrobiology , University of South Bohemia in Ceske Budejovice , Zátiší 728/II, 389 25 Vodňany , Czech Republic
| | - Jerker Fick
- Department of Chemistry , Umeå University , SE-90187 Umeå , Sweden
| | - Tomas Brodin
- Department of Wildlife, Fish, and Environmental Studies , Swedish University of Agricultural Sciences (SLU) , SE-90183 Umeå , Sweden
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30
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MacDougall-Shackleton SA, Bonier F, Romero LM, Moore IT. Glucocorticoids and "Stress" Are Not Synonymous. Integr Org Biol 2019; 1:obz017. [PMID: 33791532 PMCID: PMC7671118 DOI: 10.1093/iob/obz017] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Reference to glucocorticoids as “stress hormones” has been growing in prevalence in the literature, including in comparative and environmental endocrinology. Although glucocorticoids are elevated in response to a variety of stressors in vertebrate animals, the primary functions of glucocorticoids are not responding to stressors and they are only one component of complex suite of physiological and behavioral responses to stressors. Thus, the use of the short-hand phrase “stress hormone” can be misleading. Further, simply measuring glucocorticoids is not equivalent to measuring a stress response, nor is manipulating glucocorticoids equivalent to exposing an animal to a stressor. In this commentary we highlight the problems with using functional names for hormones, and of treating cortisol or corticosterone as synonymous with stress. We provide recommendations to add clarity to the presentation of research on this topic, and to avoid conflation of glucocorticoids with stressors and the stress response in the design of experiments.
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Affiliation(s)
| | - F Bonier
- Biology Department, Queen's University, Kingston, Ontario, Canada K7L 3N6
| | - L M Romero
- Department of Biology, Tufts University, Medford, MA 02155, USA
| | - I T Moore
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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31
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Warne RW, Baer SG, Boyles JG. Community Physiological Ecology. Trends Ecol Evol 2019; 34:510-518. [DOI: 10.1016/j.tree.2019.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 02/06/2019] [Accepted: 02/08/2019] [Indexed: 02/06/2023]
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32
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Lawrence MJ, Godin JGJ, Zolderdo AJ, Cooke SJ. Chronic Plasma Cortisol Elevation Does Not Promote Riskier Behavior in a Teleost Fish: A Test of the Behavioral Resiliency Hypothesis. Integr Org Biol 2019; 1:obz009. [PMID: 33791525 PMCID: PMC7671160 DOI: 10.1093/iob/obz009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Stressed fish have been shown to have higher predator-induced mortality than unstressed conspecifics, suggesting a role for the hypothalamic-pituitary-interrenal axis in modifying risk-taking behaviors. Yet, there is also evidence of behavioral resiliency in the face of chronic stressors. Here, we tested the behavioral resiliency hypothesis, which posits that animals can maintain consistent behavioral phenotypes in the face of significant physiological challenges. We determined whether chronic plasma cortisol elevation promotes risk-taking behaviors in a model teleost fish, the pumpkinseed sunfish (Lepomis gibbosus). Experimental fish were implanted with cocoa butter either as a sham or with cortisol. At 48 h post-implantation, the behavior of individual focal fish was tested in an experimental arena comprising of a simulated physical refuge, an open zone containing a constrained conspecific shoal, and a compartment containing either a model of a northern pike (Esox lucius) paired with corresponding pike olfactory cues in lake water or no pike model (control) paired with sham lake water cues only. The fish were assayed individually for their refuge utilization, shoaling tendency, and general activity. Neither cortisol treatment nor predation-risk treatment influenced any of these behaviors. This suggests that sunfish, in the context of our experiment, were behaviorally resilient to the physiological effects of chronic plasma cortisol elevation and in the face of an apparent threat of predation. Our results thus provide support for the behavioral resiliency hypothesis in fish under both physiological and ecological stressors. We posit that behavioral resiliency is an evolutionary adaptation ensuring appropriate responses to environmental conditions.
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Affiliation(s)
- Michael J Lawrence
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6.,Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Jean-Guy J Godin
- Department of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Aaron J Zolderdo
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6.,Queen's University Biological Station, Queen's University, Elgin, Ontario, Canada K0G 1E0
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
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33
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Lawrence MJ, Zolderdo AJ, Godin JGJ, Mandelman JW, Gilmour KM, Cooke SJ. Cortisol does not increase risk of mortality to predation in juvenile bluegill sunfish: A manipulative experimental field study. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2019; 331:253-261. [DOI: 10.1002/jez.2257] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/21/2018] [Accepted: 12/22/2018] [Indexed: 01/19/2023]
Affiliation(s)
- Michael J. Lawrence
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology; Carleton University; Ottawa Ontario Canada
| | - Aaron J. Zolderdo
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology; Carleton University; Ottawa Ontario Canada
| | | | - John W. Mandelman
- Anderson Cabot Center for Ocean Life, New England Aquarium; Boston Massachusetts
| | | | - Steven J. Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology; Carleton University; Ottawa Ontario Canada
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34
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MacLeod KJ, Sheriff MJ, Ensminger DC, Owen DAS, Langkilde T. Survival and reproductive costs of repeated acute glucocorticoid elevations in a captive, wild animal. Gen Comp Endocrinol 2018; 268:1-6. [PMID: 30016628 DOI: 10.1016/j.ygcen.2018.07.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/14/2018] [Accepted: 07/13/2018] [Indexed: 01/07/2023]
Abstract
Organisms are continuously encountering both predictable and unpredictable ecological stressors within their environment. The activation of the hypothalamic-pituitaryadrenal (stress) axis is a fundamental process allowing animals to cope with and respond to such encounters. A main consequence of HPA axis activation is the release of glucocorticoid hormones. Although short-term glucocorticoid elevations lead to changes in physiological and behavioral processes that are often adaptive, our understanding of fitness consequences of repeated acute elevations in glucocorticoid hormones over a longer time period is largely lacking. This is of particular current importance as animals are facing a significant increase in exposure to stressors including those associated with human-induced rapid environmental change. Here, we test fitness-relevant consequences of repeated exposure to glucocorticoids in the absence of natural challenges, by treating wild-caught gravid female eastern fence lizards (Sceloporus undulatus) with a daily transdermal dose of a glucocorticoid hormone until laying. This treatment causes an increase in plasma glucocorticoids that mimics the natural response lizards have when they encounter a stressor in the wild, without confounding effects associated with the encounter itself. This treatment reduced females' reproductive success (hatching success) and survival. Further, glucocorticoid-induced reductions in reproductive success were greater when females had experienced higher temperatures the previous winter. This demonstrates the potential significant consequences of repeated exposure to acute elevations in glucocorticoid hormones. Additionally, the costs of repeated glucocorticoid elevation may be further exaggerated by an individual's previous experience, such as the potential compounding effects of winter warming increasing animals' vulnerability to increased glucocorticoid levels during spring breeding.
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Affiliation(s)
- K J MacLeod
- Department of Ecosystem Science and Management, Pennsylvania State University, Forest Resources Building, University Park, PA 16802, USA; Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA; Intercollege Graduate Degree Program in Ecology, The Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA; Center for Brain, Behavior and Cognition, Pennsylvania State University, University Park, PA 16802, USA.
| | - M J Sheriff
- Department of Ecosystem Science and Management, Pennsylvania State University, Forest Resources Building, University Park, PA 16802, USA; Intercollege Graduate Degree Program in Ecology, The Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - D C Ensminger
- Department of Ecosystem Science and Management, Pennsylvania State University, Forest Resources Building, University Park, PA 16802, USA; Center for Brain, Behavior and Cognition, Pennsylvania State University, University Park, PA 16802, USA
| | - D A S Owen
- Department of Ecosystem Science and Management, Pennsylvania State University, Forest Resources Building, University Park, PA 16802, USA; Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA; Intercollege Graduate Degree Program in Ecology, The Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - T Langkilde
- Department of Biology, Pennsylvania State University, Mueller Laboratory, University Park, PA 16802, USA; Intercollege Graduate Degree Program in Ecology, The Huck Institute of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA; Center for Brain, Behavior and Cognition, Pennsylvania State University, University Park, PA 16802, USA
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35
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Tucker EK, Suski CD, Philipp MA, Jeffrey JD, Hasler CT. Glucocorticoid and behavioral variation in relation to carbon dioxide avoidance across two experiments in freshwater teleost fishes. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1842-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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36
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Ensminger DC, Langkilde T, Owen DAS, MacLeod KJ, Sheriff MJ. Maternal stress alters the phenotype of the mother, her eggs and her offspring in a wild-caught lizard. J Anim Ecol 2018; 87:1685-1697. [PMID: 30074248 DOI: 10.1111/1365-2656.12891] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/22/2018] [Indexed: 01/05/2023]
Abstract
While biomedical researchers have long appreciated the influence of maternally derived glucocorticoids (GCs) on offspring phenotype, ecologists have only recently begun exploring its impact in wild animals. Interpreting biomedical findings within an ecological context has posited that maternal stress, mediated by elevations of maternal GCs, may play an adaptive role preparing offspring for a stressful or rigorous environment. Yet, the influence of maternal stress on offspring phenotype has been little studied in wild animals. We experimentally elevated GCs to ecologically relevant levels (mimicking increases in maternal stress hormones following a nonlethal predator encounter, a heat challenge, or a chasing or confinement stressor) in female eastern fence lizards Sceloporus undulatus during gestation. We tested the hypothesis that maternally derived stress hormones themselves are sufficient to alter offspring phenotype. Specifically, we examined the effects of experimentally elevated maternal GCs on fitness-relevant traits of the mother, her eggs and her subsequent offspring. We found that daily maternal GC elevation: (a) increased maternal antipredator behaviours and postlaying glucose levels; (b) had no effect on egg morphology or caloric value, but altered yolk hormone (elevated GC) and nutrient content; and (c) altered offspring phenotype including stress-relevant physiology, morphology and behaviour. These findings reveal that maternally derived GCs alone can alter offspring phenotype in a wild animal, changes that may be mediated via maternal behaviour, and egg hormone and nutrient content. Understanding the ecological consequences of these effects under different environmental conditions will be critical for determining the adaptive significance of elevated maternal GCs for offspring.
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Affiliation(s)
- David C Ensminger
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania
| | - Tracy Langkilde
- Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania
| | - Dustin A S Owen
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| | - Kirsty J MacLeod
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Department of Biology, Mueller Laboratory, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| | - Michael J Sheriff
- Department of Ecosystem Science and Management, Pennsylvania State University, University Park, Pennsylvania.,Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
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37
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Lawrence MJ, Godin JGJ, Cooke SJ. Does experimental cortisol elevation mediate risk-taking and antipredator behaviour in a wild teleost fish? Comp Biochem Physiol A Mol Integr Physiol 2018; 226:75-82. [PMID: 30099116 DOI: 10.1016/j.cbpa.2018.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/06/2018] [Accepted: 08/03/2018] [Indexed: 10/28/2022]
Abstract
The hypothalamic-pituitary-interrenal (HPI) axis is centrally implicated in stressor mitigation in teleost fishes. Sustained HPI axis activation can be detrimental to the physiological functioning of an organism and can result in fitness-related trade-offs. Predator-induced mortality is known to be higher in stressed fish than in unstressed conspecifics, suggesting a role for the HPI axis in mediating fish behaviour. However, the underlying specific mechanism(s) for this phenomenon is(are) unknown. The purpose of the current study was to address how the HPI axis influences risk-taking, and antipredator behaviours in a wild teleost, the pumpkinseed sunfish (Lepomis gibbosus). Here, individual juvenile pumpkinseed were implanted either with cocoa butter as a sham control or with a biologically-relevant concentration of cortisol. Forty-eight hours post-implantation, fish were assessed for behavioural metrics associated with boldness and risk taking in three sequential behavioural tests: (i) a predation-risk test, (ii) an exploration tendency test, and (iii) a shoaling tendency test, with test order randomized among different trials. Cortisol treatment had no influence on antipredator, exploratory, or shoaling behaviours. However, post-attack swimming duration (in predation-risk test) and exploratory activity (in Z-maze exploration test) were significantly affected by body mass. Collectively, our results indicate that cortisol may not have a role in mediating sociability, boldness, and risk-taking behaviours in pumpkinseed sunfish, at least under the current laboratory conditions. However, cortisol may nonetheless play a role in mediating predator-prey interactions in fishes in more natural environmental settings that were not considered here.
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Affiliation(s)
- Michael J Lawrence
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada.
| | - Jean-Guy J Godin
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
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38
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Raulo A, Dantzer B. Associations between glucocorticoids and sociality across a continuum of vertebrate social behavior. Ecol Evol 2018; 8:7697-7716. [PMID: 30151183 PMCID: PMC6106170 DOI: 10.1002/ece3.4059] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 02/22/2018] [Accepted: 02/27/2018] [Indexed: 12/26/2022] Open
Abstract
The causes and consequences of individual differences in animal behavior and stress physiology are increasingly studied in wild animals, yet the possibility that stress physiology underlies individual variation in social behavior has received less attention. In this review, we bring together these study areas and focus on understanding how the activity of the vertebrate neuroendocrine stress axis (HPA-axis) may underlie individual differences in social behavior in wild animals. We first describe a continuum of vertebrate social behaviors spanning from initial social tendencies (proactive behavior) to social behavior occurring in reproductive contexts (parental care, sexual pair-bonding) and lastly to social behavior occurring in nonreproductive contexts (nonsexual bonding, group-level cooperation). We then perform a qualitative review of existing literature to address the correlative and causal association between measures of HPA-axis activity (glucocorticoid levels or GCs) and each of these types of social behavior. As expected, elevated HPA-axis activity can inhibit social behavior associated with initial social tendencies (approaching conspecifics) and reproduction. However, elevated HPA-axis activity may also enhance more elaborate social behavior outside of reproductive contexts, such as alloparental care behavior. In addition, the effect of GCs on social behavior can depend upon the sociality of the stressor (cause of increase in GCs) and the severity of stress (extent of increase in GCs). Our review shows that the while the associations between stress responses and sociality are diverse, the role of HPA-axis activity behind social behavior may shift toward more facilitating and less inhibiting in more social species, providing insight into how stress physiology and social systems may co-evolve.
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Affiliation(s)
- Aura Raulo
- Department of BiosciencesUniversity of HelsinkiHelsinkiFinland
- Zoology DepartmentUniversity of OxfordOxfordUK
| | - Ben Dantzer
- Department of PsychologyUniversity of MichiganAnn ArborMichigan
- Department of Ecology and Evolutionary BiologyUniversity of MichiganAnn ArborMichigan
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39
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Madliger CL, Love OP, Hultine KR, Cooke SJ. The conservation physiology toolbox: status and opportunities. CONSERVATION PHYSIOLOGY 2018; 6:coy029. [PMID: 29942517 PMCID: PMC6007632 DOI: 10.1093/conphys/coy029] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/18/2018] [Accepted: 05/24/2018] [Indexed: 05/21/2023]
Abstract
For over a century, physiological tools and techniques have been allowing researchers to characterize how organisms respond to changes in their natural environment and how they interact with human activities or infrastructure. Over time, many of these techniques have become part of the conservation physiology toolbox, which is used to monitor, predict, conserve, and restore plant and animal populations under threat. Here, we provide a summary of the tools that currently comprise the conservation physiology toolbox. By assessing patterns in articles that have been published in 'Conservation Physiology' over the past 5 years that focus on introducing, refining and validating tools, we provide an overview of where researchers are placing emphasis in terms of taxa and physiological sub-disciplines. Although there is certainly diversity across the toolbox, metrics of stress physiology (particularly glucocorticoids) and studies focusing on mammals have garnered the greatest attention, with both comprising the majority of publications (>45%). We also summarize the types of validations that are actively being completed, including those related to logistics (sample collection, storage and processing), interpretation of variation in physiological traits and relevance for conservation science. Finally, we provide recommendations for future tool refinement, with suggestions for: (i) improving our understanding of the applicability of glucocorticoid physiology; (ii) linking multiple physiological and non-physiological tools; (iii) establishing a framework for plant conservation physiology; (iv) assessing links between environmental disturbance, physiology and fitness; (v) appreciating opportunities for validations in under-represented taxa; and (vi) emphasizing tool validation as a core component of research programmes. Overall, we are confident that conservation physiology will continue to increase its applicability to more taxa, develop more non-invasive techniques, delineate where limitations exist, and identify the contexts necessary for interpretation in captivity and the wild.
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Affiliation(s)
- Christine L Madliger
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Dr., Ottawa, Ontario, Canada
- Department of Biological Sciences, University of Windsor, 401 Sunset Ave., Ontario, Canada
| | - Oliver P Love
- Department of Biological Sciences, University of Windsor, 401 Sunset Ave., Ontario, Canada
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, 1201 N. Galvin Parkway, Phoenix, AZ, USA
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Dr., Ottawa, Ontario, Canada
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40
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LAWRENCE MJ, ELIASON EJ, BROWNSCOMBE JW, GILMOUR KM, MANDELMAN JW, GUTOWSKY LF, COOKE SJ. Influence of supraphysiological cortisol manipulation on predator avoidance behaviors and physiological responses to a predation threat in a wild marine teleost fish. Integr Zool 2018; 13:206-218. [DOI: 10.1111/1749-4877.12282] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Michael J. LAWRENCE
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology; Carleton University; Ottawa Ontario Canada
| | - Erika J. ELIASON
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology; Carleton University; Ottawa Ontario Canada
- Department of Ecology, Evolution & Marine Biology; University of California; Santa Barbara California USA
| | | | | | - John W. MANDELMAN
- School for the Environment; University of New England; Biddeford Maine USA
- John H. Prescott Marine Laboratory; New England Aquarium; Boston Massachusetts USA
| | - Lee F.G. GUTOWSKY
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology; Carleton University; Ottawa Ontario Canada
| | - Steven J. COOKE
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology; Carleton University; Ottawa Ontario Canada
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41
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Birnie-Gauvin K, Peiman KS, Larsen MH, Aarestrup K, Gilmour KM, Cooke SJ. Comparison of vegetable shortening and cocoa butter as vehicles for cortisol manipulation in Salmo trutta. JOURNAL OF FISH BIOLOGY 2018; 92:229-236. [PMID: 29194613 DOI: 10.1111/jfb.13513] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 11/06/2017] [Indexed: 06/07/2023]
Abstract
This study demonstrates that vegetable shortening and cocoa butter are two effective vehicles for intraperitoneal cortisol implants in juvenile teleosts, specifically brown trout Salmo trutta, residing in north temperate freshwater environments. Each vehicle showed a different pattern of cortisol elevation. Vegetable shortening was found to be a more suitable vehicle for long-term cortisol elevation [elevated at 3, 6 and 9 days post treatment (dpt)], while cocoa butter may be better suited for short-term cortisol elevation (only elevated at 3 dpt). Additionally, plasma cortisol levels were higher with cortisol-vegetable shortening than with cortisol-cocoa butter implants. Plasma glucose levels were elevated 6 and 9 dpt for fishes injected with cortisol-vegetable shortening, but did not change relative to controls and shams in cortisol-cocoa butter fishes. In conclusion, vegetable shortening and cocoa butter are both viable techniques for cortisol manipulation in fishes in temperate climates, providing researchers with different options depending on study objectives.
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Affiliation(s)
- K Birnie-Gauvin
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - K S Peiman
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - M H Larsen
- Danish Centre for Wild Salmon, Brusgårdsvej 15, 8960 Randers, Denmark
| | - K Aarestrup
- DTU AQUA, National Institute of Aquatic Resources, Section for Freshwater Fisheries and Ecology, Technical University of Denmark, Vejlsøvej 39, 8600 Silkeborg, Denmark
| | - K M Gilmour
- Department of Biology, University of Ottawa, 30 Marie-Curie, Ottawa, ON, K1N 6N5, Canada
| | - S J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
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Gervasi SS, Burkett-Cadena N, Burgan SC, Schrey AW, Hassan HK, Unnasch TR, Martin LB. Host stress hormones alter vector feeding preferences, success, and productivity. Proc Biol Sci 2017; 283:rspb.2016.1278. [PMID: 27512147 DOI: 10.1098/rspb.2016.1278] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/15/2016] [Indexed: 01/05/2023] Open
Abstract
Stress hormones might represent a key link between individual-level infection outcome, population-level parasite transmission, and zoonotic disease risk. Although the effects of stress on immunity are well known, stress hormones could also affect host-vector interactions via modification of host behaviours or vector-feeding patterns and subsequent reproductive success. Here, we experimentally manipulated songbird stress hormones and examined subsequent feeding preferences, feeding success, and productivity of mosquito vectors in addition to defensive behaviours of hosts. Despite being more defensive, birds with elevated stress hormone concentrations were approximately twice as likely to be fed on by mosquitoes compared to control birds. Moreover, stress hormones altered the relationship between the timing of laying and clutch size in blood-fed mosquitoes. Our results suggest that host stress could affect the transmission dynamics of vector-borne parasites via multiple pathways.
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Affiliation(s)
- Stephanie S Gervasi
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Nathan Burkett-Cadena
- Florida Medical Entomology Laboratory, University of Florida, Vero Beach, FL 32962, USA
| | - Sarah C Burgan
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
| | - Aaron W Schrey
- Biology Department, Armstrong State University, Savannah, GA 31419, USA
| | - Hassan K Hassan
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | - Thomas R Unnasch
- Department of Global Health, University of South Florida, Tampa, FL 33620, USA
| | - Lynn B Martin
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620, USA
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43
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Moleón MS, Parachú Marcó MV, Pietrobon EO, Jahn GA, Beldomenico PM, Siroski PA. Corticosterone levels and immunological indices in stressed juvenile broad-snouted caimans. J Zool (1987) 2017. [DOI: 10.1111/jzo.12513] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. S. Moleón
- Laboratorio de Ecología de Enfermedades (ICiVet-CONICET-UNL); Esperanza Santa Fe Argentina
- Proyecto Yacaré; Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC - UNL/MMA; Santa Fe Argentina
| | - M. V. Parachú Marcó
- Proyecto Yacaré; Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC - UNL/MMA; Santa Fe Argentina
- Laboratorio de Biología Celular y Molecular (ICiVet-CONICET-UNL); Esperanza Santa Fe Argentina
| | - E. O. Pietrobon
- Laboratorio de Reproducción y Lactancia CRICYT-CONICET; Mendoza Argentina
| | - G. A. Jahn
- Laboratorio de Reproducción y Lactancia CRICYT-CONICET; Mendoza Argentina
| | - P. M. Beldomenico
- Laboratorio de Ecología de Enfermedades (ICiVet-CONICET-UNL); Esperanza Santa Fe Argentina
| | - P. A. Siroski
- Proyecto Yacaré; Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC - UNL/MMA; Santa Fe Argentina
- Laboratorio de Biología Celular y Molecular (ICiVet-CONICET-UNL); Esperanza Santa Fe Argentina
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Algera DA, Brownscombe JW, Gilmour KM, Lawrence MJ, Zolderdo AJ, Cooke SJ. Cortisol treatment affects locomotor activity and swimming behaviour of male smallmouth bass engaged in paternal care: A field study using acceleration biologgers. Physiol Behav 2017; 181:59-68. [PMID: 28866027 DOI: 10.1016/j.physbeh.2017.08.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 08/28/2017] [Accepted: 08/29/2017] [Indexed: 12/18/2022]
Abstract
Paternal care, where the male provides sole care for the developing brood, is a common form of reproductive investment among teleost fish and ubiquitous in the Centrarchidae family. Throughout the parental care period, nesting males expend energy in a variety of swimming behaviours, including routine and burst swimming, vigilantly monitoring the nest area and protecting the brood from predators. Parental care is an energetically demanding period, which is presumably made even more difficult if fish are exposed to additional challenges such as those arising from human disturbance, resulting in activation of the hypothalamic-pituitary-interrenal axis (i.e., elevation of cortisol). To study this situation, we examined the effects of experimental manipulation of the stress hormone cortisol on locomotor activity and behaviour of nest guarding male smallmouth bass (Micropterus dolomieu). We exogenously elevated circulating cortisol levels (via intracoelomic implants) and attached tri-axial accelerometers to wild smallmouth bass for three days. During the recovery period (i.e., ≤4h post-release), cortisol-treated fish exhibited significantly reduced locomotor activity and performed significantly less burst and routine swimming relative to control fish, indicating cortisol uptake was rapid, as were the associated behavioural responses. Post-recovery (i.e., >4h post-release), fish with high cortisol exhibited lower locomotor activity and reduced routine swimming relative to controls. Fish were less active and reduced routine and burst swimming at night compared to daylight hours, an effect independent of cortisol treatment. Collectively, our results suggest that cortisol treatment (as a proxy for anthropogenic disturbance and stress) contributed to altered behaviour, and consequently cortisol-treated males decreased parental investment in their brood, which could have potential fitness implications.
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Affiliation(s)
- Dirk A Algera
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada.
| | - Jacob W Brownscombe
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada
| | - Kathleen M Gilmour
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, ON, Canada
| | - Michael J Lawrence
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada
| | - Aaron J Zolderdo
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada
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45
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Bennett KA, Robinson KJ, Moss SEW, Millward S, Hall AJ. Using blubber explants to investigate adipose function in grey seals: glycolytic, lipolytic and gene expression responses to glucose and hydrocortisone. Sci Rep 2017; 7:7731. [PMID: 28798409 PMCID: PMC5552887 DOI: 10.1038/s41598-017-06037-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 06/06/2017] [Indexed: 02/02/2023] Open
Abstract
Adipose tissue is fundamental to energy balance, which underpins fitness and survival. Knowledge of adipose regulation in animals that undergo rapid fat deposition and mobilisation aids understanding of their energetic responses to rapid environmental change. Tissue explants can be used to investigate adipose regulation in wildlife species with large fat reserves, when opportunities for organismal experimental work are limited. We investigated glucose removal, lactate, glycerol and NEFA accumulation in media, and metabolic gene expression in blubber explants from wild grey seals. Glycolysis was higher in explants incubated in 25 mM glucose (HG) for 24 h compared to controls (C: 5.5 mM glucose). Adipose-derived lactate likely contributes to high endogenous glucose production in seals. Lipolysis was not stimulated by HG or high hydrocortisone (HC: 500 nM hydrocortisone) and was lower in heavier animals. HC caused NEFA accumulation in media to decrease by ~30% relative to C in females, indicative of increased lipogenesis. Lipolysis was higher in males than females in C and HG conditions. Lower relative abundance of 11-β-hydroxysteroid dehydrogenase 1 mRNA in HG explants suggests glucose involvement in blubber cortisol sensitivity. Our findings can help predict energy balance responses to stress and nutritional state in seals, and highlight the use of explants to study fat tissue function in wildlife.
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Affiliation(s)
- Kimberley A Bennett
- Division of Science, School of Science Engineering and Technology, Abertay University, Bell St, Dundee, DD1 1HG, UK.
- Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK.
| | - Kelly J Robinson
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 8LB, UK
| | - Simon E W Moss
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 8LB, UK
| | - Sebastian Millward
- Marine Biology and Ecology Research Centre, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK
| | - Ailsa J Hall
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 8LB, UK
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Cooke SJ, Birnie-Gauvin K, Lennox RJ, Taylor JJ, Rytwinski T, Rummer JL, Franklin CE, Bennett JR, Haddaway NR. How experimental biology and ecology can support evidence-based decision-making in conservation: avoiding pitfalls and enabling application. CONSERVATION PHYSIOLOGY 2017; 5:cox043. [PMID: 28835842 PMCID: PMC5550808 DOI: 10.1093/conphys/cox043] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 06/21/2017] [Accepted: 07/15/2017] [Indexed: 05/14/2023]
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.
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Affiliation(s)
- Steven J. Cooke
- Canadian Centre for Evidence-Based Conservation and Environmental Management, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Kim Birnie-Gauvin
- Canadian Centre for Evidence-Based Conservation and Environmental Management, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Robert J. Lennox
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Jessica J. Taylor
- Canadian Centre for Evidence-Based Conservation and Environmental Management, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Trina Rytwinski
- Canadian Centre for Evidence-Based Conservation and Environmental Management, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Jodie L. Rummer
- Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Craig E. Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Joseph R. Bennett
- Canadian Centre for Evidence-Based Conservation and Environmental Management, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Neal R. Haddaway
- EviEM, Stockholm Environment Institute, Box 24218, 10451 Stockholm, Sweden
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47
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Claunch NM, Frazier JA, Escallón C, Vernasco BJ, Moore IT, Taylor EN. Physiological and behavioral effects of exogenous corticosterone in a free-ranging ectotherm. Gen Comp Endocrinol 2017; 248:87-96. [PMID: 28237812 DOI: 10.1016/j.ygcen.2017.02.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/11/2017] [Accepted: 02/17/2017] [Indexed: 10/20/2022]
Abstract
In the face of global change, free-ranging organisms are expected to experience more unpredictable stressors. An understanding of how organisms with different life history strategies will respond to such changes is an integral part of biodiversity conservation. Corticosterone (CORT) levels are often used as metrics to assess the population health of wild vertebrates, despite the fact that the stress response and its effects on organismal function are highly variable. Our understanding of the stress response is primarily derived from studies on endotherms, leading to some contention on the effects of chronic stress across and within taxa. We assessed the behavioral and hormonal responses to experimentally elevated stress hormone levels in a free-ranging, arid-adapted ectotherm, the Southern Pacific rattlesnake (Crotalus helleri). Plasma CORT was significantly elevated in CORT-implanted snakes 15days after implantation. Implantation with CORT did not affect testosterone (T) levels or defensive behavior. Interestingly, we observed increased defensive behavior in snakes with more stable daily body temperatures and in snakes with higher plasma T during handling (tubing). Regardless of treatment group, those individuals with lower baseline CORT levels and higher body temperatures tended to exhibit greater increases in CORT levels following a standardized stressor. These results suggest that CORT may not mediate physiological and behavioral trait expression in arid-adapted ectotherms such as rattlesnakes.
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Affiliation(s)
- Natalie M Claunch
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93401, USA.
| | - Julius A Frazier
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93401, USA
| | - Camilo Escallón
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ben J Vernasco
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Ignacio T Moore
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Emily N Taylor
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93401, USA
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48
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Peiman KS, Birnie-Gauvin K, Midwood JD, Larsen MH, Wilson ADM, Aarestrup K, Cooke SJ. If and when: intrinsic differences and environmental stressors influence migration in brown trout (Salmo trutta). Oecologia 2017; 184:375-384. [PMID: 28488214 DOI: 10.1007/s00442-017-3873-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 04/22/2017] [Indexed: 11/30/2022]
Abstract
Partial migration is a common phenomenon, yet the causes of individual differences in migratory propensity are not well understood. We examined factors that potentially influence timing of migration and migratory propensity in a wild population of juvenile brown trout (Salmo trutta) by combining experimental manipulations with passive integrated transponder telemetry. Individuals were subjected to one of six manipulations: three designed to mimic natural stressors (temperature increase, food deprivation, and chase by a simulated predator), an injection of exogenous cortisol designed to mimic an extreme physiological challenge, a sham injection, and a control group. By measuring length and mass of 923 individuals prior to manipulation and by monitoring tagged individuals as they left the stream months later, we assessed whether pre-existing differences influenced migratory tendency and timing of migration, and whether our manipulations affected growth, condition, and timing of migration. We found that pre-existing differences predicted migration, with smaller individuals and individuals in poor condition having a higher propensity to migrate. Exogenous cortisol manipulation had the largest negative effect on growth and condition, and resulted in an earlier migration date. Additionally, low-growth individuals within the temperature and food deprivation treatments migrated earlier. By demonstrating that both pre-existing differences in organism state and additional stressors can affect whether and when individuals migrate, we highlight the importance of understanding individual differences in partial migration. These effects may carry over to influence migration success and affect the evolutionary dynamics of sub-populations experiencing different levels of stress, which is particularly relevant in a changing world.
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Affiliation(s)
- Kathryn S Peiman
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada.
| | - Kim Birnie-Gauvin
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - Jonathan D Midwood
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - Martin H Larsen
- DTU AQUA, National Institute of Aquatic Resources, Section for Freshwater Fisheries Ecology, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark.,Danish Centre for Wild Salmon, Brusgårdsvej 15, 8960, Randers, Denmark
| | - Alexander D M Wilson
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
| | - Kim Aarestrup
- DTU AQUA, National Institute of Aquatic Resources, Section for Freshwater Fisheries Ecology, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Steven J Cooke
- Fish Ecology and Conservation Physiology Laboratory, Department of Biology and Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada
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49
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Lawrence MJ, Eliason EJ, Brownscombe JW, Gilmour KM, Mandelman JW, Cooke SJ. An experimental evaluation of the role of the stress axis in mediating predator-prey interactions in wild marine fish. Comp Biochem Physiol A Mol Integr Physiol 2017; 207:21-29. [DOI: 10.1016/j.cbpa.2017.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 01/20/2017] [Accepted: 02/01/2017] [Indexed: 02/03/2023]
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50
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Guida L, Awruch C, Walker TI, Reina RD. Prenatal stress from trawl capture affects mothers and neonates: a case study using the southern fiddler ray (Trygonorrhina dumerilii). Sci Rep 2017; 7:46300. [PMID: 28401959 PMCID: PMC5388872 DOI: 10.1038/srep46300] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 03/14/2017] [Indexed: 12/14/2022] Open
Abstract
Assessing fishing effects on chondrichthyan populations has predominantly focused on quantifying mortality rates. Consequently, sub-lethal effects of capture stress on the reproductive capacity of chondrichthyans are largely unknown. We investigated the reproductive consequences of capture on pregnant southern fiddler rays (Trygonorrhina dumerilii) collected from Swan Bay, Australia, in response to laboratory-simulated trawl capture (8 h) followed immediately by air exposure (30 min). Immediately prior to, and for up to 28 days post trawling, all females were measured for body mass (BM), sex steroid concentrations (17-β estradiol, progesterone, testosterone) and granulocyte to lymphocyte (G:L) ratio. At parturition, neonates were measured for total length (TL), BM and G:L ratio. Trawling reduced maternal BM and elevated the G:L ratio for up to 28 days. Trawling did not significantly affect any sex steroid concentrations relative to controls. Neonates from trawled mothers were significantly lower in BM and TL than control animals, and had an elevated G:L ratio. Our results show that capture of pregnant T. dumerilii can influence their reproductive potential and affect the fitness of neonates. We suggest other viviparous species are likely to be similarly affected. Sub-lethal effects of capture, particularly on reproduction, require further study to improve fisheries management and conservation of chondrichthyans.
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Affiliation(s)
- L Guida
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - C Awruch
- CESIMAR (Centro Para el Estudio de Sistemas Marinos) - CENPAT- CONICET, Puerto Madryn, Chubut U9120ACD, Argentina.,School of Biological Sciences, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - T I Walker
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
| | - R D Reina
- School of Biological Sciences, Monash University, Clayton, Victoria 3800, Australia
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