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Pereira KE, Bletz MC, McCartney JA, Woodhams DC, Woodley SK. Effects of exogenous elevation of corticosterone on immunity and the skin microbiome of eastern newts ( Notophthalmus viridescens). Philos Trans R Soc Lond B Biol Sci 2023; 378:20220120. [PMID: 37305906 PMCID: PMC10258667 DOI: 10.1098/rstb.2022.0120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/15/2022] [Indexed: 06/13/2023] Open
Abstract
The amphibian chytrid fungus, Batrachochytrium salamandrivorans (Bsal) threatens salamander biodiversity. The factors underlying Bsal susceptibility may include glucocorticoid hormones (GCs). The effects of GCs on immunity and disease susceptibility are well studied in mammals, but less is known in other groups, including salamanders. We used Notophthalmus viridescens (eastern newts) to test the hypothesis that GCs modulate salamander immunity. We first determined the dose required to elevate corticosterone (CORT; primary GC in amphibians) to physiologically relevant levels. We then measured immunity (neutrophil lymphocyte ratios, plasma bacterial killing ability (BKA), skin microbiome, splenocytes, melanomacrophage centres (MMCs)) and overall health in newts following treatment with CORT or an oil vehicle control. Treatments were repeated for a short (two treatments over 5 days) or long (18 treatments over 26 days) time period. Contrary to our predictions, most immune and health parameters were similar for CORT and oil-treated newts. Surprisingly, differences in BKA, skin microbiome and MMCs were observed between newts subjected to short- and long-term treatments, regardless of treatment type (CORT, oil vehicle). Taken together, CORT does not appear to be a major factor contributing to immunity in eastern newts, although more studies examining additional immune factors are necessary. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
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Affiliation(s)
- Kenzie E. Pereira
- Department of Biology, Duquesne University, Pittsburgh, PA 15282, USA
| | - Molly C. Bletz
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Julia A. McCartney
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Douglas C. Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, MA 02125, USA
| | - Sarah K. Woodley
- Department of Biology, Duquesne University, Pittsburgh, PA 15282, USA
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Walkowski WG, Crother BI, Valverde RA. Testosterone and Corticosterone Profiles and Body Condition of Calling and Non-calling Lithobates grylio. COPEIA 2019. [DOI: 10.1643/cp-18-134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Whitney G. Walkowski
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana 70402; (WGW) . Send reprint requests to WGW
| | - Brian I. Crother
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana 70402; (WGW) . Send reprint requests to WGW
| | - Roldán A. Valverde
- Department of Biological Sciences, Southeastern Louisiana University, Hammond, Louisiana 70402; (WGW) . Send reprint requests to WGW
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Fischer CP, Romero LM. Chronic captivity stress in wild animals is highly species-specific. CONSERVATION PHYSIOLOGY 2019; 7:coz093. [PMID: 31824674 PMCID: PMC6892464 DOI: 10.1093/conphys/coz093] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/04/2019] [Accepted: 10/13/2019] [Indexed: 05/05/2023]
Abstract
Wild animals are brought into captivity for many reasons-conservation, research, agriculture and the exotic pet trade. While the physical needs of animals are met in captivity, the conditions of confinement and exposure to humans can result in physiological stress. The stress response consists of the suite of hormonal and physiological reactions to help an animal survive potentially harmful stimuli. The adrenomedullary response results in increased heart rate and muscle tone (among other effects); elevated glucocorticoid (GC) hormones help to direct resources towards immediate survival. While these responses are adaptive, overexposure to stress can cause physiological problems, such as weight loss, changes to the immune system and decreased reproductive capacity. Many people who work with wild animals in captivity assume that they will eventually adjust to their new circumstances. However, captivity may have long-term or permanent impacts on physiology if the stress response is chronically activated. We reviewed the literature on the effects of introduction to captivity in wild-caught individuals on the physiological systems impacted by stress, particularly weight changes, GC regulation, adrenomedullary regulation and the immune and reproductive systems. This paper did not review studies on captive-born animals. Adjustment to captivity has been reported for some physiological systems in some species. However, for many species, permanent alterations to physiology may occur with captivity. For example, captive animals may have elevated GCs and/or reduced reproductive capacity compared to free-living animals even after months in captivity. Full adjustment to captivity may occur only in some species, and may be dependent on time of year or other variables. We discuss some of the methods that can be used to reduce chronic captivity stress.
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Affiliation(s)
| | - L Michael Romero
- Department of Biology, 200 College Ave. Tufts University, Medford, MA 02155 USA
- Corresponding author: Department of Biology, Medford, MA 02155, USA.
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Reedy AM, Edwards A, Pendlebury C, Murdaugh L, Avery R, Seidenberg J, Aspbury AS, Gabor CR. An acute increase in the stress hormone corticosterone is associated with mating behavior in both male and female red-spotted newts, Notophthalmus viridescens. Gen Comp Endocrinol 2014; 208:57-63. [PMID: 25157790 DOI: 10.1016/j.ygcen.2014.08.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/30/2014] [Accepted: 08/14/2014] [Indexed: 11/26/2022]
Abstract
Hormones play key, functional roles in mediating the tradeoff between survival and reproduction. Glucocorticoid hormones can inhibit reproduction and improve chances of survival during periods of stress. However, glucocorticoid hormones are, at times, also associated with successfully engaging in energetically costly courtship and mating behaviors. Corticosterone (CORT), a primary glucocorticoid hormone in amphibians, reptiles and birds, may be important in activating or sustaining energetically costly mating behaviors. We used a non-invasive, water-borne hormone assay to measure CORT release rates of male and female red-spotted newts (Notophthalmus viridescens) collected when either engaged in amplexus or when not engaged in amplexus. Because amplexus is energetically costly for males, we predicted that males would have higher CORT release rates than females. We also predicted that females in amplexus would have elevated CORT release rates because the restraint of amplexus prevents foraging and breathing and may be costly. Here we show that an acute increase in CORT is associated with amplexus behavior in both male and female red-spotted newts. Additionally we demonstrate that males have higher overall CORT release rates both in and out of amplexus than do females. Our results support the hypothesis that glucocorticoid hormones are associated with energetically costly courtship and mating behaviors for both sexes.
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Affiliation(s)
- Aaron M Reedy
- Department of Biology, University of Virginia, Charlottesville, VA 22902, USA; Mountain Lake Biological Station, Pembroke, VA 24136, USA.
| | - Alex Edwards
- Department of Biology, University of Virginia, Charlottesville, VA 22902, USA; Mountain Lake Biological Station, Pembroke, VA 24136, USA
| | - Chloe Pendlebury
- Department of Biology, University of Virginia, Charlottesville, VA 22902, USA; Mountain Lake Biological Station, Pembroke, VA 24136, USA
| | - Laura Murdaugh
- Mountain Lake Biological Station, Pembroke, VA 24136, USA; Indiana University of Pennsylvania, Indiana, PA 15705, USA
| | - Ryan Avery
- Department of Biology, University of Virginia, Charlottesville, VA 22902, USA; Mountain Lake Biological Station, Pembroke, VA 24136, USA
| | | | - Andrea S Aspbury
- Mountain Lake Biological Station, Pembroke, VA 24136, USA; Department of Biology, Texas State University-San Marcos, TX 78666-4684, USA
| | - Caitlin R Gabor
- Mountain Lake Biological Station, Pembroke, VA 24136, USA; Department of Biology, Texas State University-San Marcos, TX 78666-4684, USA
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