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Tornabene BJ, Hossack BR, Breuner CW. Assay validation of saliva glucocorticoids in Columbia spotted frogs and effects of handling and marking. CONSERVATION PHYSIOLOGY 2023; 11:coad078. [PMID: 38026797 PMCID: PMC10660366 DOI: 10.1093/conphys/coad078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 08/24/2023] [Indexed: 12/01/2023]
Abstract
Non-invasive methods are important to the field of conservation physiology to reduce negative effects on organisms being studied. Glucocorticoid (GC) hormones are often used to assess health of individuals, but collection methods can be invasive. Many amphibians are imperiled worldwide, and saliva is a non- or semi-invasive matrix to measure GCs that has been partially validated for only four amphibian species. Validation ensures that assays are reliable and can detect changes in saliva corticosterone (sCORT) after exposure to stressors, but it is also necessary to ensure sCORT concentrations are correlated with plasma concentrations. To help validate the use of saliva in assessing CORT responses in amphibians, we captured uniquely marked Columbia spotted frogs (Rana luteiventris) on sequential days and collected baseline and stress-induced (after handling) samples. For a subset of individuals, we collected and quantified CORT in both saliva and blood samples, which have not been compared for amphibians. We tested several aspects of CORT responses and, by collecting across separate days, measured repeatability of CORT responses across days. We also evaluated whether methods common to amphibian conservation, such as handling alone or handling, clipping a toe and tagging elevated sCORT. Similar to previous studies, we show that sCORT is reliable concerning parallelism, recovery, precision and sensitivity. sCORT was weakly correlated with plasma CORT (R2 = 0.21), and we detected elevations in sCORT after handling, demonstrating biological validation. Toe clipping and tagging did not increase sCORT over handling alone, but repeated handling elevated sCORT for ~72 hours. However, sCORT responses were highly variable and repeatability was low within individuals and among capture sessions, contrary to previous studies with urinary and waterborne CORT. sCORT is a semi-invasive and rapid technique that could be useful to assess effects of anthropogenic change and conservation efforts, but will require careful study design and future validation.
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Affiliation(s)
- Brian J Tornabene
- U.S. Geological Survey, Northern Rocky Mountain Science Center, 32 Campus Dr., University of Montana, Missoula, Montana, 59812, USA
- Wildlife Biology Program, W. A. Franke College of Forestry & Conservation, 32 Campus Dr., University of Montana, Missoula, Montana, 59812, USA
| | - Blake R Hossack
- U.S. Geological Survey, Northern Rocky Mountain Science Center, 32 Campus Dr., University of Montana, Missoula, Montana, 59812, USA
- Wildlife Biology Program, W. A. Franke College of Forestry & Conservation, 32 Campus Dr., University of Montana, Missoula, Montana, 59812, USA
| | - Creagh W Breuner
- Wildlife Biology Program, W. A. Franke College of Forestry & Conservation, 32 Campus Dr., University of Montana, Missoula, Montana, 59812, USA
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2
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Li CY, Pan CY, Hsu Y. Age-dependent winner-loser effects in a mangrove rivulus fish, Kryptolebias marmoratus. Anim Cogn 2023; 26:1477-1488. [PMID: 37294474 DOI: 10.1007/s10071-023-01797-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/12/2023] [Accepted: 06/02/2023] [Indexed: 06/10/2023]
Abstract
The outcomes of recent fights can provide individuals information about their relative fighting ability and affect their contest decisions (winner-loser effects). Most studies investigate the presence/absence of the effects in populations/species, but here we examine how they vary between individuals of a species in response to age-dependent growth rate. Many animals' fighting ability is highly dependent on body size, so rapid growth makes information from previous fights unreliable. Furthermore, fast-growing individuals are often at earlier developmental stages and are relatively smaller and weaker than most other individuals but are growing larger and stronger quickly. We therefore predicted winner-loser effects to be less detectable in individuals with high than low growth rates and to decay more quickly. Fast-growing individuals should also display stronger winner than loser effects, because a victory when small indicates a strength which will grow, whereas a loss might soon become irrelevant. We tested these predictions using naïve individuals of a mangrove killifish, Kryptolebias marmoratus, in different growth stages. Measures of contest intensity revealed winner/loser effects only for slow-growth individuals. Both fast- and slow-growth fish with a winning experience won more of the subsequent non-escalated contests than those with a losing experience; in fast-growth individuals this effect disappeared in 3 days, but in slow-growth fish it did not. Fast-growth individuals also displayed winner effects but not loser effects. The fish therefore responded to their contest experiences in a way which reflected value of the information from these experiences to them, consistent with our predictions.
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Affiliation(s)
- Cheng-Yu Li
- Department of Biology, University of Maryland, 4094 Campus Dr, College Park, MD, 20742, USA
| | - Chun-Ying Pan
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingchou Rd, Taipei, 11677, Taiwan
| | - Yuying Hsu
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingchou Rd, Taipei, 11677, Taiwan.
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3
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White KJ, Rivas MG, Pradhan DS. Sex differences in aggressive intensities and brain steroids during status resolution in a sex changing fish, Lythrypnus dalli. Horm Behav 2023; 153:105373. [PMID: 37182511 DOI: 10.1016/j.yhbeh.2023.105373] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/16/2023]
Abstract
For vertebrates living in social hierarchies, the neuroendocrine system regulates temporal aspects of aggressive interactions during status establishment. In teleost fishes, the sex steroids 17β-estradiol (E2) and 11-ketotestosterone (KT), and the glucocorticoid, cortisol (CORT) are associated with aggression in distinct phases of their life history. Bluebanded gobies, Lythrypnus dalli, exhibit bidirectional sexual plasticity by responding to changes in their social structure by escalating aggression associated with neural changes that precede gonadal reorganization to the opposite sex. Here, we used a novel experimental design to investigate systemic (waterborne) and neural steroids associated with the earliest behavioral changes associated with feminization and masculinization during protandrous and protogynous sex change respectively. In stable social groups of wild-caught L. dalli comprising of one male and two females, we disrupted hierarchy by adding or removing a male, providing a social context for intrasexual aggression. Within only 30 min, males exhibited high rates of physical aggression inside the nest to maintain their territory, while females exhibited high rates of chases outside the nest to reestablish social status. During this period of instability, while waterborne steroids were not affected, brain E2 was higher in all fish and CORT was lower in male brains. Brain KT was higher in males who emerged as dominant compared to dominant females. Overall, a combination of differences in brain E2, CORT, and KT were important in the regulation of hierarchy re-establishment and maintenance. Rapid responses during conspecific aggressive encounters are likely mediated by neural steroid synthesis that precede changes in systemic steroids.
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Affiliation(s)
- Katrina J White
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, United States of America.
| | - Melissa G Rivas
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, United States of America
| | - Devaleena S Pradhan
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, United States of America
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Mathiron AGE, Gallego G, Silvestre F. Early-life exposure to permethrin affects phenotypic traits in both larval and adult mangrove rivulus Kryptolebias marmoratus. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 259:106543. [PMID: 37105866 DOI: 10.1016/j.aquatox.2023.106543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 04/03/2023] [Accepted: 04/19/2023] [Indexed: 05/15/2023]
Abstract
In fishes, the impacts of environmental constraints undergone during development on the behavioural response of individuals are not well understood. Obtaining more information is important since the aquatic environment is widely exposed to pollution involving neurotoxic compounds likely to cause phenotypic changes that can affect animal fitness. We explored how early exposure to the pyrethroid insecticide permethrin (PM), a compound known for its neurotoxicity, influences the phenotypic traits in both larvae and adults of the self-fertilizing fish mangrove rivulus, Kryptolebias marmoratus. First, we investigated immediate effects of PM on larvae after one-week exposure (0-7 days post-hatching): larvae exposed to high concentration (200 µg.L-1) grew less, were less active, had negative thigmotaxis and were less likely to capture prey than control individuals and those exposed to low concentration (5 µg.L-1). No difference was found between treatments when considering oxygen consumption rate and cortisol levels. Persistent effects of early exposure to PM on adults (147-149 days post-hatching) showed that fish previously exposed to high concentration of PM overcompensated growth, leading them to finally be longer and heavier than fish from other treatments. Moreover, we evidenced that levels of cortisol interacted with early PM exposure to affect behaviours during dyadic contests. Fish were more likely to initiate fighting behaviours and were more likely to be aggressive when they have low pre-contest levels of cortisol, but these effects were less pronounced when individuals were exposed to PM. This study shows that PM can have both immediate and persistent effects on phenotypic traits in a self-fertilizing vertebrate and suggests that a pyrethroid can interact with hormones action to affect animal behaviour.
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Affiliation(s)
- Anthony G E Mathiron
- Laboratory of Evolutionary and Adaptive Physiology, University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium; Institute of Life, Earth, and Environment (ILEE), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
| | - Gil Gallego
- Laboratory of Evolutionary and Adaptive Physiology, University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium
| | - Frédéric Silvestre
- Laboratory of Evolutionary and Adaptive Physiology, University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium; Institute of Life, Earth, and Environment (ILEE), University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium
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Tornabene BJ, Breuner CW, Hossack BR, Crespi EJ. Effects of salinity and a glucocorticoid antagonist, RU486, on waterborne aldosterone and corticosterone of northern leopard frog larvae. Gen Comp Endocrinol 2022; 317:113972. [PMID: 34958807 DOI: 10.1016/j.ygcen.2021.113972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/07/2021] [Accepted: 12/21/2021] [Indexed: 12/13/2022]
Abstract
Increased salinity is an emerging contaminant of concern for aquatic taxa. For amphibians exposed to salinity, there is scarce information about the physiological effects and changes in osmoregulatory hormones such as corticosterone (CORT) and aldosterone (ALDO). Recent studies have quantified effects of salinity on CORT physiology of amphibians based on waterborne hormone collection methods, but much less is known about ALDO in iono- and osmoregulation of amphibians. We re-assayed waterborne hormone samples from a previous study to investigate effects of salinity (sodium chloride, NaCl) and a glucocorticoid receptor antagonist (RU486) on ALDO of northern leopard frog (Rana pipiens) larvae. We also investigated relationships between ALDO and CORT. Waterborne ALDO marginally decreased with increasing salinity and was, unexpectedly, positively correlated with baseline and stress-induced waterborne CORT. Importantly, ALDO increased when larvae were exposed to RU486, suggesting that RU486 may also suppress mineralocorticoid receptors or that negative feedback of ALDO is mediated through glucocorticoid receptors. Alternatively, CORT increases with RU486 treatment and might be a substrate for ALDO synthesis, which could account for increases in ALDO with RU486 treatment and the correlation between CORT and ALDO. ALDO was negatively correlated with percent water, such that larvae secreting more ALDO retained less water. Although sample sizes were limited and further validation and studies are warranted, our findings expand our understanding of adrenal steroid responses to salinization in amphibians and proposes new hypotheses regarding the co-regulation of ALDO and CORT.
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Affiliation(s)
- Brian J Tornabene
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT, USA.
| | - Creagh W Breuner
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT, USA
| | - Blake R Hossack
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT, USA; U.S. Geological Survey, Northern Rocky Mountain Science Center, Missoula, MT, USA
| | - Erica J Crespi
- School of Biological Sciences, Center for Reproductive Sciences, Washington State University, Pullman, WA, USA
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Reyes F, Quintana L, Tassino B. Association of androgens and estrogens with agonistic behavior in the annual fish Austrolebias reicherti. Horm Behav 2021; 136:105064. [PMID: 34653914 DOI: 10.1016/j.yhbeh.2021.105064] [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: 12/11/2020] [Revised: 09/10/2021] [Accepted: 09/20/2021] [Indexed: 11/18/2022]
Abstract
Agonistic behavior governs the settlement of conflicts among conspecifics for limiting resources. Sex steroids play a critical role in the regulation of agonistic behavior which in turn may produce modulations in hormone titres. In this study we analyzed the association of androgens and estrogens with agonistic behavior in the annual fish Austrolebias reicherti. This native species inhabits temporary ponds that dry out completely during summer, having one of the shortest lifespans among vertebrates. They are highly sexually dimorphic and have a single breeding season during which they reproduce continuously. Here we measured plasma levels of 11-ketotestosterone (11KT) and 17β-estradiol (E2) in adult males after the resolution of a social conflict and assessed the role of the aromatase conversion of testosterone (T) to E2 in male aggression. Winners had higher levels of 11KT than losers yet; winner 11KT levels did not differ from those of males not exposed to a social challenge. E2 levels did not show differences among winners, losers or control males. However, fights under the aromatase inhibitor Fadrozole were overall less aggressive than control fights. Our results suggest an androgen response to losing a conflict and that the conversion of T to E2 is involved in the regulation of aggressive behavior. Annual fish extreme life history may give new insights on hormone-behavior interactions.
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Affiliation(s)
- Federico Reyes
- Sección Etología, Facultad de Ciencias, Universidad de la República, Uruguay; Bases Neurales de la Conducta, Departamento de Neurofisiología Molecular y Celular, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay
| | - Laura Quintana
- Bases Neurales de la Conducta, Departamento de Neurofisiología Molecular y Celular, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay
| | - Bettina Tassino
- Sección Etología, Facultad de Ciencias, Universidad de la República, Uruguay.
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Amano M, Amiya N, Fukushima K, Hagio H, Yamamoto N, Sakakura Y. Effects of crowding stress on the hypothalamo-pituitary-interrenal axis of the self-fertilizing fish, Kryptolebias marmoratus. Comp Biochem Physiol A Mol Integr Physiol 2021; 264:111110. [PMID: 34737084 DOI: 10.1016/j.cbpa.2021.111110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/26/2022]
Abstract
We tested whether crowding stress affects the hypothalamo-pituitary-interrenal (HPI) axis of the self-fertilizing fish, Kryptolebias marmoratus, which is known to be aggressive in the laboratory conditions but sometimes found as a group from a single land crab burrow in the wild. The projection of corticotropin-releasing hormone (CRH) neurons to the adrenocorticotropic hormone (ACTH) cells in the pituitary was confirmed by dual-label immunohistochemistry; CRH-immunoreactive (ir) fibers originating from cell bodies located in the lateral tuberal nucleus (NLT) of the hypothalamus were observed to project to ACTH-ir cells in the rostral pars distalis of the pituitary. Then, fish were reared solitary or in pairs for 14 days, and the number of CRH-ir cell bodies in the NLT of the hypothalamus and cortisol levels in the body without head region were compared. The number of CRH-ir cell bodies and cortisol levels were significantly higher in paired fish. These results indicate that crowding stress affects the HPI axis in K. marmoratus which thrive in small burrows with limited water volume.
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Affiliation(s)
- Masafumi Amano
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan.
| | - Noriko Amiya
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
| | - Keisuke Fukushima
- School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan
| | - Hanako Hagio
- Institute for Advanced Research, Nagoya University, Nagoya, Aichi 464-8601, Japan; Laboratory of Fish Biology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Naoyuki Yamamoto
- Laboratory of Fish Biology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Yoshitaka Sakakura
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852-8521, Japan
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Tornabene BJ, Hossack BR, Crespi EJ, Breuner CW. Corticosterone mediates a growth-survival tradeoff for an amphibian exposed to increased salinity. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2021; 335:703-715. [PMID: 34370904 DOI: 10.1002/jez.2535] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/24/2021] [Accepted: 07/26/2021] [Indexed: 01/01/2023]
Abstract
Life-history tradeoffs are common across taxa, but growth-survival tradeoffs-usually enhancing survival at a cost to growth-are less frequently investigated. Increased salinity (NaCl) is a prevalent anthropogenic disturbance that may cause a growth-survival tradeoff for larval amphibians. Although physiological mechanisms mediating tradeoffs are seldom investigated, hormones are prime candidates. Corticosterone (CORT) is a steroid hormone that independently influences survival and growth and may provide mechanistic insight into growth-survival tradeoffs. We conducted a 24-day experiment to test effects of salinity (<32-4000 mg/L) on growth, development, survival, CORT responses, and tradeoffs among traits of larval Northern Leopard Frogs (Rana pipiens). We also experimentally suppressed CORT signaling to determine whether CORT signaling mediates effects of salinity and a growth-survival tradeoff. Increased salinity reduced survival, growth, and development. Suppressing CORT signaling in conjunction with salinity reduced survival further but also attenuated the negative effects of salinity on growth, development, and water content. CORT of control larvae increased or was stable with growth and development but decreased with growth and development for those exposed to salinity. Therefore, salinity dysregulated CORT physiology. Across all treatments, larvae that survived had higher CORT than larvae that died. By manipulating CORT signaling, we provide strong evidence that CORT physiology mediates the outcome of a growth-survival tradeoff and enhances survival. To our knowledge, this is the first study to concomitantly measure tradeoffs between growth and survival and experimentally link these changes to CORT physiology. Identifying mechanistic links between stressors and fitness-related outcomes is critical to enhance our understanding of tradeoffs.
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Affiliation(s)
- Brian J Tornabene
- Wildlife Biology Program, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, Montana, USA
| | - Blake R Hossack
- Wildlife Biology Program, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, Montana, USA.,US Geological Survey, Northern Rocky Mountain Science Center, Missoula, Montana, USA
| | - Erica J Crespi
- School of Biological Sciences, Center for Reproductive Sciences, Washington State University, Pullman, Washington, USA
| | - Creagh W Breuner
- Wildlife Biology Program, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, Montana, USA
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Tornabene BJ, Hossack BR, Crespi EJ, Breuner CW. Evaluating corticosterone as a biomarker for amphibians exposed to increased salinity and ambient corticosterone. CONSERVATION PHYSIOLOGY 2021; 9:coab049. [PMID: 34249364 PMCID: PMC8254138 DOI: 10.1093/conphys/coab049] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/28/2021] [Accepted: 06/10/2021] [Indexed: 06/13/2023]
Abstract
Physiological biomarkers are commonly used to assess the health of taxa exposed to natural and anthropogenic stressors. Glucocorticoid (GC) hormones are often used as indicators of physiological stress in wildlife because they affect growth, reproduction and survival. Increased salinity from human activities negatively influences amphibians and their corticosterone (CORT; the main amphibian GC) physiology; therefore, CORT could be a useful biomarker. We evaluated whether waterborne CORT could serve as a biomarker of salt stress for three free-living amphibian species that vary in their sensitivity to salinity: boreal chorus frogs (Pseudacris maculata), northern leopard frogs (Rana pipiens) and barred tiger salamanders (Ambystoma mavortium). Across a gradient of contamination from energy-related saline wastewaters, we tested the effects of salinity on baseline and stress-induced waterborne CORT of larvae. Stress-induced, but not baseline, CORT of leopard frogs increased with increasing salinity. Salinity was not associated with baseline or stress-induced CORT of chorus frogs or tiger salamanders. Associations between CORT and salinity were also not related to species-specific sensitivities to salinity. However, we detected background environmental CORT (ambient CORT) in all wetlands and spatial variation was high within and among wetlands. Higher ambient CORT was associated with lower waterborne CORT of larvae in wetlands. Therefore, ambient CORT likely confounded associations between waterborne CORT and salinity in our analysis and possibly influenced physiology of larvae. We hypothesize that larvae may passively take up CORT from their environment and downregulate endogenous CORT. Although effects of some hormones (e.g. oestrogen) and endocrine disruptors on aquatic organisms are well described, studies investigating the occurrence and effects of ambient CORT are limited. We provide suggestions to improve collection methods, reduce variability and avoid confounding effects of ambient CORT. By making changes to methodology, waterborne CORT could still be a promising, non-invasive conservation tool to evaluate effects of salinity on amphibians.
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Affiliation(s)
- Brian J Tornabene
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT 59812, USA
| | - Blake R Hossack
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT 59812, USA
- US Geological Survey, Northern Rocky Mountain Science Center, Missoula, MT 59812, USA
| | - Erica J Crespi
- School of Biological Sciences, Center for Reproductive Sciences, Washington State University, Pullman, WA 99163, USA
| | - Creagh W Breuner
- Wildlife Biology Program, W.A. Franke College of Forestry & Conservation, University of Montana, Missoula, MT 59812, USA
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Vilella‐Pacheco Z, Mitchem LD, Formica VA, Brodie ED. Male competition reverses female preference for male chemical cues. Ecol Evol 2021; 11:4532-4541. [PMID: 33976828 PMCID: PMC8093714 DOI: 10.1002/ece3.7348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/28/2021] [Accepted: 02/10/2021] [Indexed: 11/10/2022] Open
Abstract
Females must choose among potential mates with different phenotypes in a variety of social contexts. Many male traits are inherent and unchanging, but others are labile to social context. Competition, for example, can cause physiological changes that reflect recent wins and losses that fluctuate throughout time. We may expect females to respond differently to males depending on the outcome of their most recent fight. In Bolitotherus cornutus (forked fungus beetles), males compete for access to females, but copulation requires female cooperation. In this study, we use behavioral trials to determine whether females use chemical cues to differentiate between males and whether the outcome of recent male competition alters female preference. We measured female association time with chemical cues of two size-matched males both before and after male-male competition. Females in our study preferred to associate with future losers before males interacted, but changed their preference for realized winners following male competitive interactions. Our study provides the first evidence of change in female preference based solely on the outcome of male-male competition.
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Affiliation(s)
| | - Lisa D. Mitchem
- Mountain Lake Biological Station and Department of BiologyUniversity of VirginiaCharlottesvilleVAUSA
| | | | - Edmund D. Brodie
- Mountain Lake Biological Station and Department of BiologyUniversity of VirginiaCharlottesvilleVAUSA
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Leary CJ, Baugh AT. Glucocorticoids, male sexual signals, and mate choice by females: Implications for sexual selection. Gen Comp Endocrinol 2020; 288:113354. [PMID: 31830474 DOI: 10.1016/j.ygcen.2019.113354] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 12/01/2019] [Accepted: 12/06/2019] [Indexed: 12/29/2022]
Abstract
We review work relating glucocorticoids (GCs), male sexual signals, and mate choice by females to understand the potential for GCs to modulate the expression of sexually selected traits and how sexual selection potentially feeds back on GC regulation. Our review reveals that the relationship between GC concentrations and the quality of male sexual traits is mixed, regardless of whether studies focused on structural traits (e.g., coloration) or behavioral traits (e.g., vocalizations) or were examined in developmental or activational frameworks. In contrast, the few mate choice experiments that have been done consistently show that females prefer males with low GCs, suggesting that mate choice by females favors males that maintain low levels of GCs. We point out, however, that just as sexual selection can drive the evolution of diverse reproductive strategies, it may also promote diversity in GC regulation. We then shift the focus to females where we highlight evidence indicating that stressors or high GCs can dampen female sexual proceptivity and the strength of preferences for male courtship signals. Hence, even in cases where GCs are tightly coupled with male sexual signals, the strength of sexual selection on aspects of GC physiology can vary depending on the endocrine status of females. Studies examining how GCs relate to sexual selection may shed light on how variation in stress physiology, sexual signals, and mate choice are maintained in natural populations and may be important in understanding context-dependent relationships between GC regulation and fitness.
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Affiliation(s)
- Christopher J Leary
- Department of Biology, University of Mississippi, PO Box 1848, University, MS 38677, USA.
| | - Alexander T Baugh
- Department of Biology, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA
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12
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Li CY, Tseng YC, Chen YJ, Yang Y, Hsu Y. Personality and physiological traits predict contest interactions in Kryptolebias marmoratus. Behav Processes 2020; 173:104079. [PMID: 32007560 DOI: 10.1016/j.beproc.2020.104079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 01/08/2020] [Accepted: 01/29/2020] [Indexed: 12/15/2022]
Abstract
Personality and physiological traits often have close relationships with dominance status, but the significance and/or direction of the relationships vary between studies. This study examines whether two personality traits (aggressiveness and boldness) and three physiological traits (testosterone and cortisol levels and oxygen consumption rates) are associated with contest decisions/performance using a mangrove killifish Kryptolebias marmoratus. The results show that individuals that attacked their own mirror images (an aggressiveness index) at higher rates or had higher levels of testosterone were more likely to attack their opponent and win non-escalated contests, while individuals that had higher levels of cortisol were more likely to lose. After the contests, (1) individuals that had attacked their opponents or won had higher post-contest oxygen consumption rates, and (2) individuals that had attacked their opponents also had higher post-contest levels of cortisol. Although no significant correlations were detected among pre-contest physiological traits, post-contest levels of cortisol were positively correlated with oxygen consumption rates. Overall, personality and physiological traits provide useful predictors for the fish's contest decisions/performance. Contest interactions subsequently modified post-contest physiological traits and potentially also promoted associations between them. Nevertheless, the fish's physiological traits remained rather consistent over the entire study period.
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Affiliation(s)
- Cheng-Yu Li
- Department of Biology, University of Maryland, 4094 Campus Dr, College Park, MD 20742, USA
| | - Yung-Che Tseng
- Marine Research Station, ICOB, Academia Sinica, No. 23-10, Dawen Rd, Jiaoxi Township, Yilan County 262, Taiwan
| | - Yu-Ju Chen
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingchou Rd, Taipei 11677, Taiwan; Biodiversity Program, Taiwan International Graduate Program, Academia Sinica, No. 128, Section 2, Academia Rd, Taipei 115, Taiwan
| | - Yusan Yang
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, 105 Clapp Hall, Pittsburgh, PA, 15260, USA
| | - Yuying Hsu
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingchou Rd, Taipei 11677, Taiwan.
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13
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Paciorek T, Joseph L. Behavioral and Endocrine Alterations to Partner Interactions and Offspring Care during Periods of Conflict. Integr Org Biol 2020; 2:obaa002. [PMID: 33791546 PMCID: PMC7671132 DOI: 10.1093/iob/obaa002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Biparental care has evolved to ensure successful rearing of offspring. However, separation during periods of care can lead to conflicts that might negatively impact pair bonds and offspring care. In this study, pair-bonded convict cichlids (Amatitlania nigrofasciata) were observed for changes in behavior toward their partners and offspring before and after a period of separation. Males and females were designated either as a Resident (remain with offspring) or Removed (separated from partner and offspring for 5 days) individual. Behaviors between partners and toward offspring were measured before and after separation, and compared to the levels of behavior of control pairs (never separated), as well as individuals introduced to a novel partner instead. Cortisol levels of Resident male and female A. nigrofasciata were assayed using water-borne hormone collection before and after separation. Aggression between pair bond members did increase following reintroduction, but did not lead to the termination of pair bonds. Resident females showed more aggression to novel partners than Resident males. Offspring care decreased in both Resident and Removed females. Experimental pairs decreased the amount of time spent interacting with intruders. Cortisol levels were significantly higher among experimental pairs compared with control pairs that did not experience a separation. Females (both control and experimental) showed small, yet significant increases in cortisol levels, while both control and experimental males did not. These results suggest that while pair bonds appear resilient, prolonged separations influence pair bond and parental care dynamics, both behaviorally and hormonally, and require pairs to re-establish roles, resulting in less time caring for offspring.
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Affiliation(s)
- Timothy Paciorek
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| | - Leese Joseph
- Department of Biology, DeSales University, Center Valley, PA 18034, USA
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14
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Pawluk RJ, Garcia de Leaniz C, Cable J, Tiddeman B, Consuegra S. Colour plasticity in response to social context and parasitic infection in a self-fertilizing fish. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181418. [PMID: 31417688 PMCID: PMC6689574 DOI: 10.1098/rsos.181418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 05/23/2019] [Indexed: 06/10/2023]
Abstract
Many animal species rely on changes in body coloration to signal social dominance, mating readiness and health status to conspecifics, which can in turn influence reproductive success, social dynamics and pathogen avoidance in natural populations. Such colour changes are thought to be controlled by genetic and environmental conditions, but their relative importance is difficult to measure in natural populations, where individual genetic variability complicates data interpretation. Here, we studied shifts in melanin-related body coloration in response to social context and parasitic infection in two naturally inbred lines of a self-fertilizing fish to disentangle the relative roles of genetic background and individual variation. We found that social context and parasitic infection had a significant effect on body coloration that varied between genetic lines, suggesting the existence of genotype by environment interactions. In addition, individual variation was also important for some of the colour attributes. We suggest that the genetic background drives colour plasticity and that this can maintain phenotypic variation in inbred lines, an adaptive mechanism that may be particularly important when genetic diversity is low.
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Affiliation(s)
| | | | - Joanne Cable
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Bernard Tiddeman
- Department of Computer Science, Aberystwyth University, Aberystwyth SY23 3FL, UK
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15
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Kuo J, Chang Y, Chen Y, Hsu Y. Influence of previous agonistic interactions with conspecifics on contest decisions. Ethology 2019. [DOI: 10.1111/eth.12919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Jing‐Huan Kuo
- Department of Life Science National Taiwan Normal University Taipei Taiwan
| | - Yu‐Ting Chang
- Department of Life Science National Taiwan Normal University Taipei Taiwan
| | - Yu‐Ju Chen
- Department of Life Science National Taiwan Normal University Taipei Taiwan
- Biodiversity Program, Taiwan International Graduate Program Academia Sinica Taipei Taiwan
| | - Yuying Hsu
- Department of Life Science National Taiwan Normal University Taipei Taiwan
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16
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Berbel-Filho WM, Rodríguez-Barreto D, Berry N, Garcia De Leaniz C, Consuegra S. Contrasting DNA methylation responses of inbred fish lines to different rearing environments. Epigenetics 2019; 14:939-948. [PMID: 31144573 DOI: 10.1080/15592294.2019.1625674] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Epigenetic mechanisms generate plastic phenotypes that can become locally adapted across environments. Disentangling genomic from epigenomic variation is challenging in sexual species due to genetic variation among individuals, but it is easier in self-fertilizing species. We analysed DNA methylation patterns of two highly inbred strains of a naturally self-fertilizing fish reared in two contrasting environments to investigate the obligatory (genotype-dependent), facilitated (partially depend on the genotype) or pure (genotype-independent) nature of the epigenetic variation. We found higher methylation differentiation between genotypes than between environments. Most methylation differences between environments common to both strains followed a pattern where the two genotypes (inbred lines) responded to the same environmental context with contrasting DNA methylation levels (facilitated epialleles). Our findings suggest that, at least in part, DNA methylation could depend on the dynamic interaction between the genotype and the environment, which could explain the plasticity of epigenetically mediated phenotypes.
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Affiliation(s)
| | | | - Nikita Berry
- a Department of Biosciences, Swansea University , Swansea , UK
| | | | - Sofia Consuegra
- a Department of Biosciences, Swansea University , Swansea , UK
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17
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Turko AJ, Doherty JE, Yin-Liao I, Levesque K, Kruth P, Holden JM, Earley RL, Wright PA. Prolonged survival out of water is linked to a slow pace of life in a selfing amphibious fish. J Exp Biol 2019; 222:jeb.209270. [DOI: 10.1242/jeb.209270] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 11/25/2019] [Indexed: 12/25/2022]
Abstract
Metabolic rate and life history traits vary widely both among and within species reflecting trade-offs in energy allocation, but the proximate and ultimate causes of variation are not well understood. We tested the hypothesis that these trade-offs are mediated by environmental heterogeneity, using isogenic strains of the amphibious fish Kryptolebias marmoratus that vary in the amount of time each can survive out of water. Consistent with pace of life theory, the strain that survived air exposure the longest generally exhibited a “slow” phenotype including the lowest metabolic rate, largest scope for metabolic depression, slowest consumption of energy stores, and least investment in reproduction under standard conditions. Growth rates were fastest in the otherwise “slow” strain, however. We then tested for fitness trade-offs between “fast” and “slow” strains using microcosms where fish were held with either constant water availability or under fluctuating conditions where water was absent for half of the experiment. Under both conditions the “slow” strain grew larger and was in better condition, and under fluctuating conditions the “slow” strain produced more embryos. However, the “fast” strain had larger adult population sizes under both conditions, indicating that fecundity is not the sole determinant of population size in this species. We conclude that genetically based differences in pace of life of amphibious fish determine survival duration out of water. Relatively “slow” fish tended to perform better under conditions of limited water availability, but there was no detectable cost under control conditions. Thus, pace of life differences may reflect a conditionally neutral instead of antagonistic trade-off.
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Affiliation(s)
- Andy J. Turko
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Justine E. Doherty
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Irene Yin-Liao
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Kelly Levesque
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Perryn Kruth
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Joseph M. Holden
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA, 35487
| | - Ryan L. Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA, 35487
| | - Patricia A. Wright
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
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18
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Currie S, Tattersall GJ. Social cues can push amphibious fish to their thermal limits. Biol Lett 2018; 14:20180492. [PMID: 30381451 PMCID: PMC6227855 DOI: 10.1098/rsbl.2018.0492] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/04/2018] [Indexed: 01/09/2023] Open
Abstract
Social context can impact how animals respond to changes in their physical environment. We used an aggressive, amphibious fish, the mangrove rivulus (Kryptolebias marmoratus) with environmentally determined sociality to test the hypothesis that social interactions would push fish to their thermal limits. We capitalized on the propensity of rivulus to emerge from warming water and demonstrated that social stimuli, produced by their reflection, increased emersion threshold without changing the critical thermal maximum, effectively diminishing thermal safety margins. When rivulus were denied air access, surface behaviours dramatically increased, supplanting social interactions. This suggests that assessing the terrestrial environment is crucially important. We conclude that social stimulation narrows the scope for survival in naturally stressful conditions.
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Affiliation(s)
- Suzanne Currie
- Department of Biology, Acadia University, Wolfville, Nova Scotia, Canada
- Department of Biology, Mount Allison University, Sackville, New Brunswick, Canada
| | - Glenn J Tattersall
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
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19
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Li CY, Huang SP, Garcia M, Fuller A, Hsu Y, Earley RL. Sexual phenotype drives variation in endocrine responses to social challenge in a quasi-clonal animal. ROYAL SOCIETY OPEN SCIENCE 2018; 5:180002. [PMID: 29765691 PMCID: PMC5936956 DOI: 10.1098/rsos.180002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
In many species, males tend to behave more aggressively than females and female aggression often occurs during particular life stages such as maternal defence of offspring. Though many studies have revealed differences in aggression between the sexes, few studies have compared the sexes in terms of their neuroendocrine responses to contest experience. We investigated sex differences in the endocrine response to social challenge using mangrove rivulus fish, Kryptolebias marmoratus. In this species, sex is determined environmentally, allowing us to produce males and hermaphrodites with identical genotypes. We hypothesized that males would show elevated androgen levels (testosterone and 11-ketotestosterone) following social challenge but that hermaphrodite responses might be constrained by having to maintain both testicular and ovarian tissue. To test this hypothesis, we staged fights between males and between hermaphrodites, and then compared contest behaviour and hormone responses between the sexes. Hermaphrodites had significantly higher oestradiol but lower 11-ketotestosterone than males before contests. Males took longer to initiate contests but tended to fight more aggressively and sustain longer fights than hermaphrodites. Males showed a dramatic post-fight increase in 11-ketotestosterone but hermaphrodites did not. Thus, despite being genetically identical, males and hermaphrodites exhibit dramatically different fighting strategies and endocrine responses to contests.
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Affiliation(s)
- Cheng-Yu Li
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, USA
| | - Shu-Ping Huang
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingchou Rd, Taipei 116, Taiwan, Republic of China
| | - Mark Garcia
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, USA
| | - Adam Fuller
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, USA
| | - Yuying Hsu
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Tingchou Rd, Taipei 116, Taiwan, Republic of China
| | - Ryan L. Earley
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, USA
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20
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Boulton K, Walling CA, Grimmer AJ, Rosenthal GG, Wilson AJ. Phenotypic and genetic integration of personality and growth under competition in the sheepshead swordtail, Xiphophorus birchmanni. Evolution 2017; 72:187-201. [PMID: 29148573 PMCID: PMC5814916 DOI: 10.1111/evo.13398] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 01/11/2023]
Abstract
Competition for resources including food, physical space, and potential mates is a fundamental ecological process shaping variation in individual phenotype and fitness. The evolution of competitive ability, in particular social dominance, depends on genetic (co)variation among traits causal (e.g., behavior) or consequent (e.g., growth) to competitive outcomes. If dominance is heritable, it will generate both direct and indirect genetic effects (IGE) on resource‐dependent traits. The latter are expected to impose evolutionary constraint because winners necessarily gain resources at the expense of losers. We varied competition in a population of sheepshead swordtails, Xiphophorus birchmanni, to investigate effects on behavior, size, growth, and survival. We then applied quantitative genetic analyses to determine (i) whether competition leads to phenotypic and/or genetic integration of behavior with life history and (ii) the potential for IGE to constrain life history evolution. Size, growth, and survival were reduced at high competition. Male dominance was repeatable and dominant individuals show higher growth and survival. Additive genetic contributions to phenotypic covariance were significant, with the G matrix largely recapitulating phenotypic relationships. Social dominance has a low but significant heritability and is strongly genetically correlated with size and growth. Assuming causal dependence of growth on dominance, hidden IGE will therefore reduce evolutionary potential.
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Affiliation(s)
- Kay Boulton
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, United Kingdom
| | - Craig A Walling
- Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Edinburgh EH9 3FL, United Kingdom
| | - Andrew J Grimmer
- Marine Biology and Ecology Research Centre, School of Biology and Marine Sciences, Plymouth University, Drake Circus, Plymouth, Devon PL48AA, United Kingdom
| | - Gil G Rosenthal
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, Texas 77843.,Centro de Investigaciones Científicas de las Huastecas "Aguazarca,", Calnali, Hidalgo, Mexico
| | - Alastair J Wilson
- Centre for Ecology and Conservation, Biosciences, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, Cornwall TR10 9EZ, United Kingdom
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21
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Contest experience and body size affect different types of contest decisions. Anim Cogn 2016; 19:1183-1193. [DOI: 10.1007/s10071-016-1028-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 08/15/2016] [Accepted: 08/22/2016] [Indexed: 10/21/2022]
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22
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Kelley JL, Yee MC, Brown AP, Richardson RR, Tatarenkov A, Lee CC, Harkins TT, Bustamante CD, Earley RL. The Genome of the Self-Fertilizing Mangrove Rivulus Fish, Kryptolebias marmoratus: A Model for Studying Phenotypic Plasticity and Adaptations to Extreme Environments. Genome Biol Evol 2016; 8:2145-54. [PMID: 27324916 PMCID: PMC4987111 DOI: 10.1093/gbe/evw145] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The mangrove rivulus (Kryptolebias marmoratus) is one of two preferentially self-fertilizing hermaphroditic vertebrates. This mode of reproduction makes mangrove rivulus an important model for evolutionary and biomedical studies because long periods of self-fertilization result in naturally homozygous genotypes that can produce isogenic lineages without significant limitations associated with inbreeding depression. Over 400 isogenic lineages currently held in laboratories across the globe show considerable among-lineage variation in physiology, behavior, and life history traits that is maintained under common garden conditions. Temperature mediates the development of primary males and also sex change between hermaphrodites and secondary males, which makes the system ideal for the study of sex determination and sexual plasticity. Mangrove rivulus also exhibit remarkable adaptations to living in extreme environments, and the system has great promise to shed light on the evolution of terrestrial locomotion, aerial respiration, and broad tolerances to hypoxia, salinity, temperature, and environmental pollutants. Genome assembly of the mangrove rivulus allows the study of genes and gene families associated with the traits described above. Here we present a de novo assembled reference genome for the mangrove rivulus, with an approximately 900 Mb genome, including 27,328 annotated, predicted, protein-coding genes. Moreover, we are able to place more than 50% of the assembled genome onto a recently published linkage map. The genome provides an important addition to the linkage map and transcriptomic tools recently developed for this species that together provide critical resources for epigenetic, transcriptomic, and proteomic analyses. Moreover, the genome will serve as the foundation for addressing key questions in behavior, physiology, toxicology, and evolutionary biology.
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Affiliation(s)
- Joanna L Kelley
- School of Biological Sciences and Center for Reproductive Biology, Washington State University, Pullman, Washington
| | - Muh-Ching Yee
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California
| | - Anthony P Brown
- School of Biological Sciences and Center for Reproductive Biology, Washington State University, Pullman, Washington
| | | | - Andrey Tatarenkov
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California
| | | | | | | | - Ryan L Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama
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23
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Resource availability and predation risk influence contest behavior and dominance hierarchies in crayfish. Behav Ecol Sociobiol 2016. [DOI: 10.1007/s00265-016-2139-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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24
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Scarsella GE, Duque KS, Wong SC, Sivaraman B, Earley RL. Hormonal Responses to Noncontact Aggression in Convict Cichlid Fish. ACTA ACUST UNITED AC 2016; 325:219-30. [PMID: 27076438 DOI: 10.1002/jez.2010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 02/20/2016] [Accepted: 02/22/2016] [Indexed: 11/07/2022]
Abstract
This study explored whether convict cichlid fish mount a hormonal response to aggressive encounters where dominance status remains unresolved. Hormone samples were collected at two time points before an aggressive interaction to obtain confinement-induced and baseline measures, and at one time point following a contest across a clear partition (experimental) or exposure to an opaque partition with an opponent on the opposite side (control). There was no overall significant effect of treatment (control vs. experimental) on hormone release rates but there were trends for cortisol and testosterone (T). A priori linear contrasts showed that individuals that engaged in aggressive interactions had lower postfight cortisol and T release rates than controls, suggesting that aggression, in this context, might attenuate the synthesis of both hormones. Cortisol decreased significantly between initial confinement and baseline, indicating that individuals habituate to the water-borne hormone collection procedure. Contrary to expectation, individuals with higher baseline T and 11-ketotestosterone (KT) release rates took longer to initiate conflict. None of the other measures of behavior were predicted by baseline hormone release rates, and contest behavior did not predict postfight hormone release rates. There was a significant positive relationship between KT and T at all time points. As with studies that employ mirror image stimulation, we found no hormonal response to unresolved contests despite high levels of aggressive behavior. Our study is unique because we demonstrate that animals engaged in conflict with live opponents also do not mount a significant hormonal response when clear dominance relationships are not established.
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Affiliation(s)
- Grace E Scarsella
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama
| | - Kevin S Duque
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama
| | - Stephanie C Wong
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama
| | - Boopathy Sivaraman
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama
| | - Ryan L Earley
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama
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25
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Weinersmith KL, Hanninen AF, Sih A, McElreath R, Earley RL. The relationship between handling time and cortisol release rates changes as a function of brain parasite densities in California killifish Fundulus parvipinnis. JOURNAL OF FISH BIOLOGY 2016; 88:1125-1142. [PMID: 26806153 DOI: 10.1111/jfb.12894] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 11/25/2015] [Indexed: 06/05/2023]
Abstract
This study validated a technique for non-invasive hormone measurements in California killifish Fundulus parvipinnis, and looked for associations between cortisol (a stress hormone) and 11-ketotestosterone (KT, an androgen) release rates and the density or intensity of the trematode parasites Euhaplorchis californiensis (EUHA) and Renicola buchanani (RENB) in wild-caught, naturally infected F. parvipinnis. In experiment 1, F. parvipinnis were exposed to an acute stressor by lowering water levels to dorsal-fin height and repeatedly handling the fish over the course of an hour. Neither parasite was found to influence cortisol release rates in response to this acute stressor. In experiment 2, different F. parvipinnis were exposed on four consecutive days to the procedure for collecting water-borne hormone levels and release rates of 11-KT and cortisol were quantified. This design examined whether F. parvipinnis perceived the water-borne collection procedure to be a stressor, while also exploring how parasites influenced hormone release rates under conditions less stressful than those in experiment 1. No association was found between RENB and hormone release rates, or between EUHA and 11-KT release rates. The interaction between EUHA density and handling time, however, was an important predictor of cortisol release rates. The relationship between handling time and cortisol release rates was negative for F. parvipinnis harbouring low or intermediate density infections, and became positive for fish harbouring high densities of EUHA.
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Affiliation(s)
- K L Weinersmith
- Department of Environmental Science and Policy, University of California, Davis, CA, 95616, U.S.A
| | - A F Hanninen
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, 35487, U.S.A
| | - A Sih
- Department of Environmental Science and Policy, University of California, Davis, CA, 95616, U.S.A
| | - R McElreath
- Department of Anthropology, University of California, Davis, CA, 95616, U.S.A
| | - R L Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, 35487, U.S.A
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26
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Chen TH, Wu YT, Ding WH. UV-filter benzophenone-3 inhibits agonistic behavior in male Siamese fighting fish (Betta splendens). ECOTOXICOLOGY (LONDON, ENGLAND) 2016; 25:302-309. [PMID: 26589946 DOI: 10.1007/s10646-015-1588-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/10/2015] [Indexed: 06/05/2023]
Abstract
Benzophenone-3 (BP-3) is a widely used organic UV-filter compound. Despite the frequent occurrence of BP-3 in aquatic environments, little is known about its effect on fish behavior. The aim of this study was to investigate the endocrine disrupting effects of BP-3 in male fighting fish (Betta splendens) with a focus on agonistic behavior. Male fighting fish were exposed to 10, 100, and 1000 μg/L BP-3, as well as a solvent control (0.1% ethanol) and a positive control (100 ng/L 17α-ethynylestradiol, EE2), for 28 days. At the beginning and the end of exposure, standard length and body mass of the fish were measured for calculating the condition factor (CF). In addition, spontaneous swimming activity (total distance moved) and agonistic behavior (maximum velocity and duration of opercular display in front of a mirror) were also quantified. At the end of exposure, the fish gonads were sampled for gonadosomatic index (GSI) measurement and histology. After the exposure, CF was significantly decreased in the 1000 μg/L BP-3 groups. Spontaneous swimming activity was not affected. However, maximum velocity was significantly reduced in the EE2 and 1000 μg/L BP-3 treatments; duration of opercular display was significantly decreased in the EE2 and 10 and 1000 μg/L BP-3 treatments. GSI was not significantly different between groups. There was a slight but statistically significant decrease of relative proportion of mature spermatozoa in testicular tissue in the 100 μg/L BP-3 treatment. Collectively, our results demonstrate that BP-3 can disrupt agonistic behavior of male fighting fish, indicating the endocrine disrupting activity of this compound.
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Affiliation(s)
- Te-Hao Chen
- National Museum of Marine Biology and Aquarium, 2 Houwan Rd., Checheng, Pingtung, Taiwan.
- Institute of Marine Biology, National Dong Hwa University, 2 Houwan Rd., Checheng, Pingtung, Taiwan.
| | - Yea-Ting Wu
- Institute of Marine Biology, National Dong Hwa University, 2 Houwan Rd., Checheng, Pingtung, Taiwan
| | - Wang-Hsien Ding
- Department of Chemistry, National Central University, 300, Jhongda Rd., Jhongli, Taoyuan, Taiwan
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27
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Johnson EL, Weinersmith KL, Earley RL. Changes in reproductive physiology of mangrove rivulus Kryptolebias marmoratus following exposure to environmentally relevant doses of ethinyl oestradiol. JOURNAL OF FISH BIOLOGY 2016; 88:774-786. [PMID: 26563824 DOI: 10.1111/jfb.12814] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 09/18/2015] [Indexed: 06/05/2023]
Abstract
Kryptolebias marmoratus exposed to 4 ng l(-1) of ethinyl oestradiol (EE2) for 30 days experienced significant changes in endogenous 17β-oestradiol (E2) and 11-ketotestosterone (KT) and qualitative changes in gonad morphology. Both hermaphrodites and males showed a significant decrease in E2, whereas only males exhibited a significant decrease in KT. Exposure to EE2 resulted in a decrease in spermatid and spermatocyte density in males and an increase in the number of early stage oocytes in hermaphrodites.
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Affiliation(s)
- E L Johnson
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, U.S.A
| | - K L Weinersmith
- Department of BioSciences, Rice University, 6100 Main Street, MS-140, Houston, TX 77005, U.S.A
| | - R L Earley
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Box 870344, Tuscaloosa, AL 35487, U.S.A
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Aubin‐Horth N. Using an integrative approach to investigate the evolution of behaviour. Evol Appl 2016; 9:166-80. [PMID: 27087846 PMCID: PMC4780388 DOI: 10.1111/eva.12300] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 07/24/2015] [Indexed: 12/26/2022] Open
Abstract
Behaviour is a central focus of interest in biology because it has an impact on several aspects of an organism's life. Evolutionary biologists have realised the advantage of an integrative approach that jointly studies the molecular, cellular and physiological levels of an individual to link them with the organismal behavioural phenotype. First, this mechanistic information helps in understanding physiological and evolutionary constraints acting on the behavioural response to the environment and its evolution. Second, it furthers our understanding of the process of molecular convergent evolution. Finally, we learn about natural variation in molecular, cellular and physiological traits present in wild populations and their underlying genetic basis, which can be a substrate for selection to act on. I illustrate these points using our work on behaviour variation in fishes. The information on the mechanistic bases of behaviour variation in various species and behaviours will contribute to an ecological annotation of genes and to uncover new mechanisms implicated in how this astonishing behavioural diversity arose, is maintained and will evolve.
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Affiliation(s)
- Nadia Aubin‐Horth
- Département de biologie & Institut de Biologie Intégrative et des SystèmesUniversité LavalQuébecQCCanada
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Garcia MJ, Williams J, Sinderman B, Earley RL. Ready for a fight? The physiological effects of detecting an opponent's pheromone cues prior to a contest. Physiol Behav 2015; 149:1-7. [DOI: 10.1016/j.physbeh.2015.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/05/2015] [Accepted: 05/16/2015] [Indexed: 10/23/2022]
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Avise JC, Tatarenkov A. Population genetics and evolution of the mangrove rivulus Kryptolebias marmoratus, the world's only self-fertilizing hermaphroditic vertebrate. JOURNAL OF FISH BIOLOGY 2015; 87:519-538. [PMID: 26223378 DOI: 10.1111/jfb.12741] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 06/09/2015] [Indexed: 05/20/2023]
Abstract
The mangrove rivulus, Kryptolebias marmoratus (Rivulidae, Cyprinodontiformes), is phylogenetically embedded within a large clade of oviparous (egg laying) and otherwise mostly gonochoristic (separate sex) killifish species in the circumtropical suborder Aplocheiloidei. It is unique in its reproductive mode: K. marmoratus is essentially the world's only vertebrate species known to engage routinely in self-fertilization as part of a mixed-mating strategy of selfing plus occasional outcrossing with gonochoristic males. This unique form of procreation has profound population-genetic and evolutionary-genetic consequences that are the subject of this review.
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Affiliation(s)
- J C Avise
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, U.S.A
| | - A Tatarenkov
- Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697, U.S.A
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Li CY, Earley RL, Huang SP, Hsu Y. Fighting experience alters brain androgen receptor expression dependent on testosterone status. Proc Biol Sci 2015; 281:20141532. [PMID: 25320171 DOI: 10.1098/rspb.2014.1532] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Contest decisions are influenced by the outcomes of recent fights (winner-loser effects). Steroid hormones and serotonin are closely associated with aggression and therefore probably also play important roles in mediating winner-loser effects. In mangrove rivulus fish, Kryptolebias marmoratus, individuals with higher testosterone (T), 11-ketotestosterone and cortisol levels are more capable of winning, but titres of these hormones do not directly mediate winner-loser effects. In this study, we investigated the effects of winning/losing experiences on brain expression levels of the receptor genes for androgen (AR), oestrogen α/β (ERα/β), glucocorticoid (GR) and serotonin (5-HT1AR). The effect of contest experience on AR gene expression depended on T levels: repeated losses decreased, whereas repeated wins increased AR gene expression in individuals with low T but not in individuals with medium or high T levels. These results lend strong support for AR being involved in mediating winner-loser effects, which, in previous studies, were more detectable in individuals with lower T. Furthermore, the expression levels of ERα/β, 5-HT1AR and GR genes were higher in individuals that initiated contests against larger opponents than in those that did not. Overall, contest experience, underlying endocrine state and hormone and serotonin receptor expression patterns interacted to modulate contest decisions jointly.
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Affiliation(s)
- Cheng-Yu Li
- Department of Life Science, National Taiwan Normal University, 88, Section 4, Ting-Chou Road, Taipei 11677, Taiwan, Republic of China
| | - Ryan L Earley
- Department of Biological Sciences, University of Alabama, 300 Hackberry Lane, Tuscaloosa, AL 35401, USA
| | - Shu-Ping Huang
- Department of Life Science, National Taiwan Normal University, 88, Section 4, Ting-Chou Road, Taipei 11677, Taiwan, Republic of China
| | - Yuying Hsu
- Department of Life Science, National Taiwan Normal University, 88, Section 4, Ting-Chou Road, Taipei 11677, Taiwan, Republic of China
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van Breukelen NA, Snekser JL, Itzkowitz M. Male convict cichlid 11-ketotestosterone levels throughout the reproductive cycle: an exploratory profile study in laboratory and field populations. PeerJ 2015; 3:e949. [PMID: 26020006 PMCID: PMC4435447 DOI: 10.7717/peerj.949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 04/20/2015] [Indexed: 11/29/2022] Open
Abstract
The convict cichlid (Amatitlania nigrofasciata) has been extensively examined in relation to many behavioral topics, such as courtship, pair-bonding, bi-parental care, and territoriality. Recently, this model species has been utilized in studies on genetics, endocrinology, and neuroanatomy, with an ultimate goal of connecting behavior with its underlying mechanisms. The goal of this study was two-fold: (1) profile the circulating levels of plasma 11KT in the male convict cichlid at multiple points during the reproductive cycle and (2) generally compare the hormonal profiles of the widely used laboratory populations and those of a free-living population in the streams of Costa Rica. The results of the field experiment showed that male convict cichlids had higher levels of circulating 11KT during courtship and lower during the parental care and non-breeding phases. The profile of the laboratory population was similar to the profile of the free-living individuals, with significantly higher levels of 11KT occurring during courtship than during parental care, though the level of 11KT during non-breeding phase was elevated in the laboratory. The high levels of 11KT during courtship and low levels of 11KT during parental care found in both the field and the laboratory is similar to what has been reported in other species of teleosts, and may suggest an important function of 11KT in the expression of courtship behavior and the subsequent onset of parental behaviors in this model species.
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Affiliation(s)
| | | | - Murray Itzkowitz
- Lehigh University, Department of Biological Sciences , Bethlehem, PA , USA
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Heintz MM, Brander SM, White JW. Endocrine Disrupting Compounds Alter Risk-Taking Behavior in Guppies (Poecilia reticulata). Ethology 2015. [DOI: 10.1111/eth.12362] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Melissa M. Heintz
- Department of Biology and Marine Biology; University of North Carolina Wilmington; Wilmington NC USA
| | - Susanne M. Brander
- Department of Biology and Marine Biology; University of North Carolina Wilmington; Wilmington NC USA
| | - James W. White
- Department of Biology and Marine Biology; University of North Carolina Wilmington; Wilmington NC USA
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Boulton K, Couto E, Grimmer AJ, Earley RL, Canario AVM, Wilson AJ, Walling CA. How integrated are behavioral and endocrine stress response traits? A repeated measures approach to testing the stress-coping style model. Ecol Evol 2015; 5:618-33. [PMID: 25691986 PMCID: PMC4328767 DOI: 10.1002/ece3.1395] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 12/15/2014] [Indexed: 11/16/2022] Open
Abstract
It is widely expected that physiological and behavioral stress responses will be integrated within divergent stress-coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive–proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of among-individual variation. While there is some evidence of association between endocrine and behavioral stress response traits, few studies incorporate repeated observations of both. To test this model, we use a multivariate, repeated measures approach in a captive-bred population of Xiphophorus birchmanni. We quantify among-individual variation in behavioral stress response to an open field trial (OFT) with simulated predator attack (SPA) and measure waterborne steroid hormone levels (cortisol, 11-ketotestosterone) before and after exposure. Under the mild stress stimulus (OFT), (multivariate) behavioral variation among individuals was consistent with a strong axis of personality (shy–bold) or coping style (reactive–proactive) variation. However, behavioral responses to a moderate stressor (SPA) were less repeatable, and robust statistical support for repeatable endocrine state over the full sampling period was limited to 11-ketotestosterone. Although post hoc analysis suggested cortisol expression was repeatable over short time periods, qualitative relationships between behavior and glucocorticoid levels were counter to our a priori expectations. Thus, while our results clearly show among-individual differences in behavioral and endocrine traits associated with stress response, the correlation structure between these is not consistent with a simple proactive–reactive axis of integrated stress-coping style. Additionally, the low repeatability of cortisol suggests caution is warranted if single observations (or indeed repeat measures over short sampling periods) of glucocorticoid traits are used in ecological or evolutionary studies focussed at the individual level.
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Affiliation(s)
- Kay Boulton
- Institute of Evolutionary Biology, University of Edinburgh West Mains Road, Edinburgh, EH9 3JT, U.K
| | - Elsa Couto
- CCMar, University of Algarve Campus de Gambelas, 8005-139, Faro, Portugal
| | - Andrew J Grimmer
- College of Life and Environmental Sciences, University of Exeter Cornwall Campus, Treliever Road, Penryn, Cornwall, TR10 9EZ, U.K
| | - Ryan L Earley
- Department of Biological Sciences, University of Alabama 300 Hackberry Lane, Box 870344, SEC Building, Tuscaloosa, Alabama, 35487
| | | | - Alastair J Wilson
- College of Life and Environmental Sciences, University of Exeter Cornwall Campus, Treliever Road, Penryn, Cornwall, TR10 9EZ, U.K
| | - Craig A Walling
- Institute of Evolutionary Biology, University of Edinburgh West Mains Road, Edinburgh, EH9 3JT, U.K
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Serra M, Wolkers CPB, Urbinati EC. Novelty of the arena impairs the cortisol-related increase in the aggression of matrinxã (Brycon amazonicus). Physiol Behav 2015; 141:51-7. [PMID: 25578544 DOI: 10.1016/j.physbeh.2015.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/29/2014] [Accepted: 01/07/2015] [Indexed: 11/28/2022]
Abstract
The dichotomic effect of a cortisol level rise in vertebrate behavior has been widely observed. Generally, a chronic increase of the hormone level inhibits aggression, while an acute rise increases aggression. However, in this study, we show that this increase in aggression through an acute rise of cortisol also depends on the context in which the agonistic interaction occurs in the tropical fish matrinxã, Brycon amazonicus. We combined two factors: the type of housing (resident or non-resident in the trial arena) and the level of cortisol at the beginning of the fight (normal level - control, or high level - hydrocortisone-treated fish). The cortisol treatment increased the aggressiveness in the resident fish, but this effect was not observed in the non-resident fish, which fought in an unknown arena. The novelty of the arena may have elicited an "alerted state" in the non-resident fish; in this situation the fight was not the priority, and the cortisol effect in aggression could be impaired by a conflict between motivational systems (fear and aggression). In our knowledge, in fish, the increase of aggression promoted by an acute rise in cortisol levels was always tested and observed in a resident context, and the inhibition of cortisol effect in the agonist behavior is demonstrated for the first time. As the cortisol effect in aggression is observed in several taxa, the inhibition of aggressiveness increased by the novelty of the arena should be investigated in other groups to clarify the dynamics of this effect of cortisol in animal behavior.
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Affiliation(s)
- Mônica Serra
- Centro de Aquicultura da Unesp, Universidade Estadual Paulista - UNESP, Via de Acesso Prof. Paulo Donato Castelane, 14.884-900 Jaboticabal, SP, Brazil.
| | - Carla Patrícia Bejo Wolkers
- Centro de Aquicultura da Unesp, Universidade Estadual Paulista - UNESP, Via de Acesso Prof. Paulo Donato Castelane, 14.884-900 Jaboticabal, SP, Brazil
| | - Elisabeth Criscuolo Urbinati
- Centro de Aquicultura da Unesp, Universidade Estadual Paulista - UNESP, Via de Acesso Prof. Paulo Donato Castelane, 14.884-900 Jaboticabal, SP, Brazil
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Warne RW, Proudfoot GA, Crespi EJ. Biomarkers of animal health: integrating nutritional ecology, endocrine ecophysiology, ecoimmunology, and geospatial ecology. Ecol Evol 2015; 5:557-66. [PMID: 25691980 PMCID: PMC4328761 DOI: 10.1002/ece3.1360] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 11/17/2014] [Indexed: 11/25/2022] Open
Abstract
Diverse biomarkers including stable isotope, hormonal, and ecoimmunological assays are powerful tools to assess animal condition. However, an integrative approach is necessary to provide the context essential to understanding how biomarkers reveal animal health in varied ecological conditions. A barrier to such integration is a general lack of awareness of how shared extraction methods from across fields can provide material from the same animal tissues for diverse biomarker assays. In addition, the use of shared methods for extracting differing tissue fractions can also provide biomarkers for how animal health varies across time. Specifically, no study has explicitly illustrated the depth and breadth of spacial and temporal information that can be derived from coupled biomarker assessments on two easily collected tissues: blood and feathers or hair. This study used integrated measures of glucocorticoids, stable isotopes, and parasite loads in the feathers and blood of fall-migrating Northern saw-whet owls (Aegolius acadicus) to illustrate the wealth of knowledge about animal health and ecology across both time and space. In feathers, we assayed deuterium (δD) isotope and corticosterone (CORT) profiles, while in blood we measured CORT and blood parasite levels. We found that while earlier migrating owls had elevated CORT levels relative to later migrating birds, there was also a disassociation between plasma and feather CORT, and blood parasite loads. These results demonstrate how these tissues integrate time periods from weeks to seasons and reflect energetic demands during differing life stages. Taken together, these findings illustrate the potential for integrating diverse biomarkers to assess interactions between environmental factors and animal health across varied time periods without the necessity of continually recapturing and tracking individuals. Combining biomarkers from diverse research fields into an integrated framework hold great promise for advancing our understanding of environmental effects on animal health.
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Affiliation(s)
- Robin W Warne
- Department of Biology, Vassar College 124 Raymond Ave, Poughkeepsie, New York, 12604
| | - Glenn A Proudfoot
- Department of Biology, Vassar College 124 Raymond Ave, Poughkeepsie, New York, 12604
| | - Erica J Crespi
- Department of Biology, Vassar College 124 Raymond Ave, Poughkeepsie, New York, 12604
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Kolluru GR, Walz J, Hanninen AF, Downey K, Kalbach B, Gupta S, Earley RL. Exploring behavioral and hormonal flexibility across light environments in guppies from low-predation populations. BEHAVIOUR 2015. [DOI: 10.1163/1568539x-00003264] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Phenotypic flexibility is essential for organisms to respond to changing environments. Guppies experience light environments that alter their visibility to conspecifics and predators. We used guppies from populations with low rates of predation by fish, but which may be subject to avian predators, to test the hypotheses that conspicuous behaviors and the androgens that mediate them are reduced under high light, and that cortisol levels are increased under high light because the perceived risk is stressful. We found reduced courtship, potentially driven by the reduced female response to courtship, under high light. Aggression and testosterone levels were higher in the absence of females. We found elevated androgen and decreased cortisol levels following social interactions, but no relationship between hormones and behavior, and no influence of light level on hormones. We forward explanations for these results and advocate understanding the flexible response to light environments in a range of guppy populations.
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Affiliation(s)
- Gita R. Kolluru
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Julia Walz
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Amanda F. Hanninen
- bDepartment of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
- cDepartment of Biology, University of Virginia, Charlottesville, VA, USA
| | - Kate Downey
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Brandy Kalbach
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Shelly Gupta
- aBiological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Ryan L. Earley
- bDepartment of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
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Li CY, Yang Y, Lee PY, Hsu Y. Opponent familiarity and contest experience jointly influence contest decisions in Kryptolebias marmoratus. Front Zool 2014; 11:92. [PMID: 25530793 PMCID: PMC4271475 DOI: 10.1186/s12983-014-0092-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 12/04/2014] [Indexed: 11/10/2022] Open
Abstract
Introduction Individual recognition and winner/loser effects both play important roles in animal contests, but how their influences are integrated to affect an individual’s contest decisions in combination remains unclear. Individual recognition provides an animal with relatively precise information about its ability to defeat conspecifics that it has fought previously. Winner/loser effects, conversely, rely on sampling information about how an animal’s ability to win compares with those of others in the population. The less precise information causing winner/loser effects should therefore be more useful to an individual facing an unfamiliar opponent. In this study, we used Kryptolebias marmoratus, a hermaphroditic mangrove killifish, to test whether winner/loser effects do depend on opponent familiarity. In addition, as previous studies have shown that subordinates that behave aggressively sometimes suffer post-retreat retaliation from contest winners, we also explored this aspect of contest interaction in K. marmoratus. Results In the early stages of a contest, subordinates facing an unfamiliar dominant were more likely to signal their aggressiveness with either gill displays or attacks rather than retreating immediately. A winning experience then increased the likelihood that the most aggressive behavioral pattern the subordinates exhibited would be attacks rather than gill displays, irrespective of their opponents’ familiarity. Dominants that received a losing experience and faced an unfamiliar opponent were less likely than others to launch attacks directly. And subordinates that challenged dominants with more aggressive tactics but still lost received more post-retreat attacks from their dominant opponents. Conclusions Subordinates’ contest decisions were influenced by both their contest experience and the familiarity of their opponents, but these influences appeared at different stages of a contest and did not interact significantly with each other. The influence of a losing experience on dominants’ contest decisions, however, did depend on their subordinate opponents’ familiarity. Subordinates and dominants thus appeared to integrate information from the familiarity of their opponents and the outcome of previous contests differently, which warrants further investigation. The higher costs that dominants imposed on subordinates that behaved more aggressively toward them may have been to deter them from either fighting back or challenging them in the future.
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Affiliation(s)
- Cheng-Yu Li
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Ting-Chou Rd, Taipei, 11677 Taiwan
| | - Yusan Yang
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Ting-Chou Rd, Taipei, 11677 Taiwan
| | - Pey-Yi Lee
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Ting-Chou Rd, Taipei, 11677 Taiwan
| | - Yuying Hsu
- Department of Life Science, National Taiwan Normal University, No. 88, Section 4, Ting-Chou Rd, Taipei, 11677 Taiwan
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Ros AFH, Damjanovic K, Glauser G, Bshary R. No scope for social modulation of steroid levels in a year-round territorial damselfish. ACTA ACUST UNITED AC 2014; 323:80-8. [PMID: 25366877 DOI: 10.1002/jez.1900] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Revised: 09/15/2014] [Accepted: 09/15/2014] [Indexed: 11/05/2022]
Abstract
Both latitude and mating system have been proposed to shape relationships between steroid hormone levels and social behavior. Recently it has been postulated that species with long lasting non-seasonal territorial behavior have low androgen responsiveness. Tropical damselfishes are an ideal family to test this proposition because they show a large variety in mating systems. Here we contribute to the comparative dataset by measuring the response in steroid levels after social modulation in the banded sergeant, Abudefduf septemfasciatus, a species with non-seasonal territoriality. In highly territorial and brooding males, we found low androgen and cortisol levels that did not increase after experimental intraspecific simulated territorial intrusions (STI tests). No relationship was found between the variation in steroid hormone levels and territorial responses to naturally occurring territorial intrusions. Although steroid levels were low, male A. septemfasciatus were highly territorial both to STI challenges and to fishes that passed the territory. They often chased intruders for several meters away from the territory. This indicates that during nest defence in a non-seasonal territorial damselfish species, territorial behaviors are shown independent of variation in androgen and cortisol levels.
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Affiliation(s)
- Albert Frank Huascar Ros
- Department of Behavioural Ecology, Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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Baird TA, Lovern MB, Shine R. Heightened aggression and winning contests increase corticosterone but decrease testosterone in male Australian water dragons. Horm Behav 2014; 66:393-400. [PMID: 24907453 DOI: 10.1016/j.yhbeh.2014.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 05/25/2014] [Accepted: 05/27/2014] [Indexed: 11/19/2022]
Abstract
Water dragons (Intellegama [Physignathus] lesueurii) are large (to >1m) agamid lizards from eastern Australia. Males are fiercely combative; holding a territory requires incessant displays and aggression against other males. If a dominant male is absent, injured or fatigued, another male soon takes over his territory. Our sampling of blood from free-ranging adult males showed that baseline levels of both testosterone and corticosterone were not related to a male's social tactic (territorial versus non-territorial), or his frequency of advertisement display, aggression, or courtship behavior. Even when we elicited intense aggression by non-territorial males (by temporarily removing territory owners), testosterone did not increase with the higher levels of aggression that ensued. Indeed, testosterone levels decreased in males that won contests. In contrast, male corticosterone levels increased with the heightened aggression during unsettled conditions, and were higher in males that won contests. High chronic male-male competition in this dense population may favor high testosterone levels in all adult males to facilitate advertisement and patrol activities required for territory maintenance (by dominant animals), and to maintain readiness for territory take-overs (in non-territorial animals). Corticosterone levels increased in response to intense aggression during socially unstable conditions, and were higher in contest winners than losers. A positive correlation between the two hormones during socially unstable conditions suggests that the high stress of contests decreased androgen production. The persistent intense competition in this population appears to exact a high physiological cost, which together with our observation that males sometimes lose their territories to challengers may indicate cycling between these two tactics to manage long-term energetic costs.
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Affiliation(s)
- Troy A Baird
- Department of Biology, University of Central Oklahoma, USA.
| | - Matthew B Lovern
- Department of Zoology, Oklahoma State University, Stillwater, OK, USA 74078.
| | - Richard Shine
- School of Biological Sciences, University of Sydney, NSW, Australia.
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Ros AF, Vullioud P, Bruintjes R, Vallat A, Bshary R. Intra- and interspecific challenges modulate cortisol but not androgen levels in a year-round territorial damselfish. J Exp Biol 2014; 217:1768-74. [DOI: 10.1242/jeb.093666] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Interactions between individuals of different species are commonplace in animal communities. Some behaviors displayed during these interspecific social interactions may be very similar to those displayed during intraspecific social interactions. However, whether functional analogies between intra- and interspecific behaviors translate at the proximate level into an overlap in their underlying endocrine mechanisms remain largely unknown. Because steroids both mediate social behaviors and respond to them, we approached this question by comparing the behavioral and steroid response of free living dusky gregories (Stegastes nigricans [Lacepède, 1802]) to standardized territorial intrusions (sTI) of either conspecific or heterospecific food competitors. S. nigricans is a year-round territorial fish that “cultivates” the algae on which it feeds and is highly aggressive to both intra- and interspecific intruders. Behavioral differences between intra- and interspecific aggressive responses to sTI were marginal, and sTI tests caused an increase in cortisol levels that was positively related with the levels of aggression. In contrast, androgen levels did not increase in response to sTI, yet they showed a positive relationship with agonistic behavior. These results parallel a pattern that was first described for year-round territorial bird species. Furthermore they suggest that changes in endocrine-hormone levels during territoriality might be independent of the species that induces the territorial response.
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Hsu Y, Huang YY, Wu YT. Multiple contest experiences interact to influence each other's effect on subsequent contest decisions in a mangrove killifish. Anim Cogn 2013; 17:165-75. [PMID: 23760869 DOI: 10.1007/s10071-013-0649-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 05/19/2013] [Accepted: 05/23/2013] [Indexed: 10/26/2022]
Abstract
Many animals modify behavioural decisions based on information they have previously acquired. Contest behaviour is often affected by previous contest experiences: individuals behave more and less aggressively after a victory and defeat, respectively (winner/loser effect). Individuals in the field sometimes encounter multiple competitors in quick succession, but whether these experiences interact to influence each other's importance is unclear. We tested five hypotheses for experience interaction (no interaction, retroactive interference, proactive interaction, reinforcement and diminishing returns) using Kryptolebias marmoratus. Focal individuals were paired up with opponents having the same 1-month contest outcome (1 month before the experiment), as this difference in actual or perceived fighting ability has been shown to affect the fish's response to new experiences. We gave the focal individual of a pair a winning or losing experience on day 1. Then both fish of the pair received the same winning, losing or no-contest experience on day 2. Then we organised fights between the two. The effect of a day-1 losing experience did depend on the fish's actual or perceived fighting ability: one-month losers readily showed loser effects from the day-1 losing experience, irrespective of the day-2 experience (i.e. no interaction between day-1 and day-2 experiences). One-month winners, however, only showed loser effects from a day-1 losing experience when the day-2 experience was also a loss (i.e. reinforcement). Day-1 winning experiences did not interact with day-2 experiences in 1-month losers or winners. Therefore, multiple experiences sometimes reinforce each other, but how they combine to influence behaviour depends on an individual's actual or perceived fighting ability.
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Affiliation(s)
- Yuying Hsu
- Department of Life Science, National Taiwan Normal University, 88, Section 4, Ting-Chou Rd., Taipei, 11677, Taiwan,
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Hirschenhauser K, Gahr M, Goymann W. Winning and losing in public: audiences direct future success in Japanese quail. Horm Behav 2013; 63:625-33. [PMID: 23454001 DOI: 10.1016/j.yhbeh.2013.02.010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 01/31/2013] [Accepted: 02/10/2013] [Indexed: 01/23/2023]
Abstract
Among vertebrates, winning a fight enhances the probability of future victories and vice versa and the role of post-conflict testosterone in mediating this 'winner effect' is widely accepted. In a series of staged fights of Japanese quail (Coturnix japonica) we tested both opponents' pre-fight and post-conflict testosterone, behavior and dominance status after returning to their social groups. We found that the presence of a familiar mixed-sex audience during the encounter modulated both the testosterone response and the long-term success after a fighting experience. 'Public losers' but not 'public winners' lacked a post-conflict testosterone response, whereas without an audience both winners and losers increased testosterone metabolite levels. Long-lasting winner and loser effects exclusively occurred when the performance information was perceived by a mixed-sex audience. In further experiments we manipulated the testosterone responsiveness of either the loser or the winner. An artificial post-conflict testosterone surge after having lost a fight effectively reversed the loser effect in Japanese quail. In contrast, the 'winner effect' was not changed by blocking testosterone after the fight. Overall, male Japanese quails' post-conflict testosterone was connected to the audiences and thus, own or the observers' perception of the challenge rather than to winning or losing a fight.
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Affiliation(s)
- Katharina Hirschenhauser
- Department of Behavioural Neurobiology, Max-Planck-Institute for Ornithology, Eberhard-Gwinner-Straße Haus 6a, D-82319 Seewiesen, Germany.
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Corticosteroid receptor gene expression is related to sex and social behaviour in a social fish. Comp Biochem Physiol A Mol Integr Physiol 2013; 164:438-46. [DOI: 10.1016/j.cbpa.2012.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 11/30/2012] [Accepted: 12/08/2012] [Indexed: 11/21/2022]
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Gabor CR, Fisher MC, Bosch J. A non-invasive stress assay shows that tadpole populations infected with Batrachochytrium dendrobatidis have elevated corticosterone levels. PLoS One 2013; 8:e56054. [PMID: 23418508 PMCID: PMC3572145 DOI: 10.1371/journal.pone.0056054] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 01/08/2013] [Indexed: 12/23/2022] Open
Abstract
Batrachochytrium dendrobatidis (Bd) is a fungus that causes the disease chytridiomycosis and is associated with widespread amphibian declines. Populations vary in their susceptibility to Bd infections, and the virulence of the infecting lineage can also vary. Both of these factors may manifest as a differential physiological stress response. In addition, variation in disease susceptibility across amphibian populations may be influenced by immunosuppression caused by chronic stress imposed by environmental factors. Here, we use a non-invasive water-borne hormone technique to assess stress levels (corticosterone) of free-living tadpole populations that are infected by Bd. We found that corticosterone release rates were higher in infected populations of two species of tadpoles (Alytes obstetricans and A. muletensis) than in an uninfected population for both species. The relationship between corticosterone and the intensity of infection differed between species, with only the infected A. obstetricans population showing a significant positive correlation. The higher corticosterone release rates found in A. obstetricans may be an outcome of infection by a highly virulent lineage of Bd (BdGPL), whereas A. muletensis is infected with a less virulent lineage (BdCAPE). These results suggest that different lineages of Bd impose different levels of stress on the infected animals, and that this may influence survival. The next step is to determine whether higher corticosterone levels make individuals more susceptible to Bd or if Bd infections drive the higher corticosterone levels.
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Affiliation(s)
- Caitlin R Gabor
- Department of Biology, Texas State University, San Marcos, Texas, United States of America.
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Earley RL, Lu CK, Lee IH, Wong SC, Hsu Y. Winner and loser effects are modulated by hormonal states. Front Zool 2013; 10:6. [PMID: 23399457 PMCID: PMC3598835 DOI: 10.1186/1742-9994-10-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 02/05/2013] [Indexed: 11/10/2022] Open
Abstract
Introduction Many animals use information acquired from recent experiences to modify their responses to new situations. Animals’ decisions in contests also depend on their previous experience: after recent victories individuals tend to behave more aggressively and after defeats more submissively. Although these winner and/or loser effects have been reported for animals of different taxa, they have only recently been shown to be flexible traits, which can be influenced by extrinsic factors. In a mangrove killifish (Kryptolebias marmoratus), for instance, individuals which lost an earlier contest were more likely than others to alter contest decisions after a recent win/loss. This result suggests that individuals perceiving themselves to have worse fighting abilities are more inclined to adjust contest strategy based on new information. If this is the case, an individual’s propensity to modify behaviour after a win/loss might also be modulated by intrinsic mechanisms related to its ability to fight. Stress and sex steroid hormones are often associated with an individual’s contest behaviour and performance, so, in this study, we tested the hypothesis that an individual’s propensity to change behaviour after wins or losses also depends on its hormonal state. Results Our results show that an individual’s propensity to adjust contest decisions after wins and losses does depend on its hormonal state: individuals with lower levels of cortisol (F), testosterone (T) and 11-ketotestosterone (KT) are more receptive than others to the influence of recent contest experiences, especially losing experiences, and the influences last longer. Furthermore, although winning and losing experiences resulted in significant changes in behaviour, they did not bring about a significant change in the levels of F, T, KT or oestradiol (E2). Conclusions This study shows that an individual’s receptivity to the influence of recent wins and losses is modulated by its internal state, as well as by extrinsic factors. Individuals with hormonal profiles corresponding to lower aggressiveness and a reduced likelihood of winning were more likely to alter contest decisions after a recent win/loss. The results also suggest that F, T, KT and E2 are not the primary physiological mechanisms mediating winner-loser effects in this fish.
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Affiliation(s)
- Ryan L Earley
- Department of Life Science, National Taiwan Normal University, No, 88, Section 4, Ting-Chou Rd, Taipei 11677, TAIWAN.
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Kelley JL, Yee MC, Lee C, Levandowsky E, Shah M, Harkins T, Earley RL, Bustamante CD. The possibility of de novo assembly of the genome and population genomics of the mangrove rivulus, Kryptolebias marmoratus. Integr Comp Biol 2012; 52:737-42. [PMID: 22723055 PMCID: PMC3501098 DOI: 10.1093/icb/ics094] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
How organisms adapt to the range of environments they encounter is a fundamental question in biology. Elucidating the genetic basis of adaptation is a difficult task, especially when the targets of selection are not known. Emerging sequencing technologies and assembly algorithms facilitate the genomic dissection of adaptation and population differentiation in a vast array of organisms. Here we describe the attributes of Kryptolebias marmoratus, one of two known self-fertilizing hermaphroditic vertebrates that make this fish an attractive genetic system and a model for understanding the genomics of adaptation. Long periods of selfing have resulted in populations composed of many distinct naturally homozygous strains with a variety of identifiable, and apparently heritable, phenotypes. There also is strong population genetic structure across a diverse range of mangrove habitats, making this a tractable system in which to study differentiation both within and among populations. The ability to rear K. marmoratus in the laboratory contributes further to its value as a model for understanding the genetic drivers for adaptation. To date, microsatellite markers distinguish wild isogenic strains but the naturally high homozygosity improves the quality of de novo assembly of the genome and facilitates the identification of genetic variants associated with phenotypes. Gene annotation can be accomplished with RNA-sequencing data in combination with de novo genome assembly. By combining genomic information with extensive laboratory-based phenotyping, it becomes possible to map genetic variants underlying differences in behavioral, life-history, and other potentially adaptive traits. Emerging genomic technologies provide the required resources for establishing K. marmoratus as a new model organism for behavioral genetics and evolutionary genetics research.
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Affiliation(s)
- Joanna L Kelley
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.
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Friesen CN, Chapman LJ, Aubin-Horth N. Holding water steroid hormones in the African cichlid fish Pseudocrenilabrus multicolor victoriae. Gen Comp Endocrinol 2012; 179:400-5. [PMID: 23022581 DOI: 10.1016/j.ygcen.2012.07.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 07/24/2012] [Accepted: 07/27/2012] [Indexed: 11/27/2022]
Abstract
Measuring hormone levels multiple times on the same individual across different life stages or treatments can facilitate our understanding of hormonal regulation of physiological and behavioral events. The conventional method of hormone measurement requires blood sampling, which is potentially lethal to small individuals. In fishes, there is an alternative non-invasive method of hormone measurement using the release of hormones across gill membranes from blood into holding water. Validation of this method is required to evaluate its application value to different species. In the present study we used the maternal mouth-brooding African cichlid fish, Pseudocrenilabrus multicolor victoriae to (i) investigate whether handling involved in using the holding water technique is a stressor by measuring excreted cortisol in male and female P. multicolor handled one or multiple times, (ii) validate use of this technique by quantifying the relationship between plasma and holding water measures of sex hormones in male P. multicolor, and (iii) demonstrate the biological relevance of this technique using excreted levels of sex hormones in female P. multicolor across different reproductive stages. Excreted cortisol and estradiol levels did not differ between fish handled one or more times, suggesting that the repeated sampling approach over the breeding cycle that we propose to use does not affect the excreted level of the hormone of interest. Measurements from plasma and holding water samples were positively related for both testosterone and estradiol, indicating that the holding water technique is a reliable index of plasma hormone levels. Excreted sex hormone levels varied with reproductive state, suggesting that the technique is a useful, non-invasive measure of sex hormone levels in P. multicolor.
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Affiliation(s)
- Caitlin N Friesen
- Department of Biology, McGill University, 1205 Docteur Penfield, Montreal, QC, Canada H3A 1B1.
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Oswald ME, Drew RE, Racine M, Murdoch GK, Robison BD. Is Behavioral Variation along the Bold-Shy Continuum Associated with Variation in the Stress Axis in Zebrafish? Physiol Biochem Zool 2012; 85:718-28. [DOI: 10.1086/668203] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Earley RL, Hanninen AF, Fuller A, Garcia MJ, Lee EA. Phenotypic plasticity and integration in the mangrove rivulus (Kryptolebias marmoratus): a prospectus. Integr Comp Biol 2012; 52:814-27. [PMID: 22990587 DOI: 10.1093/icb/ics118] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The mangrove rivulus (Kryptolebias marmoratus) is a small fish native to mangrove ecosystems in Florida, the Caribbean, Central America, and South America. This species is one of only two self-fertilizing, hermaphroditic vertebrates capable of producing offspring that are genetically identical to both the parent and all siblings. Long bouts of selfing result in individuals with completely homozygous genotypes, effectively allowing for the production of "clones." Rivulus is also extremely sensitive to environmental change, both during development and adulthood. Life-history traits, behavior, physiology, morphology, and even sexual phenotype are shaped to a large extent by the interaction of genes with the environment, and many of these traits appear to co-vary. True reaction norms can be generated for this species in much the same way as has been done for clonally reproducing invertebrates and plants that have contributed immensely to our understanding of the evolution of phenotypic plasticity. That is, rivulus provides the opportunity to place individuals with identical genotypes in many different environments at any point during ontogeny or adulthood. In addition, rivulus populations are characterized by high genotypic diversity, a luxury not afforded by many clonal vertebrates, which allows us to evaluate variation among genotypes in the shape of reaction norms and in patterns of covariance among traits. We provide background information on phenotypic plasticity and phenotypic integration, coupled with a description of characteristics that we feel qualify rivulus as a potentially powerful model in which to study the evolution of reaction norms and covariance among traits.
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Affiliation(s)
- Ryan L Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA.
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