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Morin A, Culbert BM, Mehdi H, Balshine S, Turko AJ. Status-dependent metabolic effects of social interactions in a group-living fish. Biol Lett 2024; 20:20240056. [PMID: 39045657 PMCID: PMC11267398 DOI: 10.1098/rsbl.2024.0056] [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: 02/02/2024] [Revised: 05/14/2024] [Accepted: 06/12/2024] [Indexed: 07/25/2024] Open
Abstract
Social interactions can sometimes be a source of stress, but social companions can also ameliorate and buffer against stress. Stress and metabolism are closely linked, but the degree to which social companions modulate metabolic responses during stressful situations-and whether such effects differ depending on social rank-is poorly understood. To investigate this question, we studied Neolamprologus pulcher, a group-living cichlid fish endemic to Lake Tanganyika and measured the metabolic responses of dominant and subordinate individuals when they were either visible or concealed from one another. When individuals could see each other, subordinates had lower maximum metabolic rates and tended to take longer to recover following an exhaustive chase compared with dominants. In contrast, metabolic responses of dominants and subordinates did not differ when individuals could not see one another. These findings suggest that the presence of a dominant individual has negative metabolic consequences for subordinates, even in stable social groups with strong prosocial relationships.
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Affiliation(s)
- André Morin
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada
- School of Life and Environmental Sciences, Deakin University, 75 Pigdons Road, Geelong, Victoria, Australia
| | - Brett M. Culbert
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada
| | - Hossein Mehdi
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada
| | - Sigal Balshine
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada
| | - Andy J. Turko
- Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada
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2
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Culbert BM, Border SE, Fialkowski RJ, Bolitho I, Dijkstra PD. Social status influences relationships between hormones and oxidative stress in a cichlid fish. Horm Behav 2023; 152:105365. [PMID: 37119610 DOI: 10.1016/j.yhbeh.2023.105365] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 04/11/2023] [Accepted: 04/12/2023] [Indexed: 05/01/2023]
Abstract
An individual's social environment can have widespread effects on their physiology, including effects on oxidative stress and hormone levels. Many studies have suggested that variation in oxidative stress experienced by individuals of different social statuses might be due to endocrine differences, however, few studies have evaluated this hypothesis. Here, we assessed whether a suite of markers associated with oxidative stress in different tissues (blood/plasma, liver, and gonads) had social status-specific relationships with circulating testosterone or cortisol levels in males of a cichlid fish, Astatotilapia burtoni. Across all fish, blood DNA damage (a global marker of oxidative stress) and gonadal synthesis of reactive oxygen species [as indicated by NADPH-oxidase (NOX) activity] were lower when testosterone was high. However, high DNA damage in both the blood and gonads was associated with high cortisol in subordinates, but low cortisol in dominants. Additionally, high cortisol was associated with greater production of reactive oxygen species (greater NOX activity) in both the gonads (dominants only) and liver (dominants and subordinates). In general, high testosterone was associated with lower oxidative stress across both social statuses, whereas high cortisol was associated with lower oxidative stress in dominants and higher oxidative stress in subordinates. Taken together, our results show that differences in the social environment can lead to contrasting relationships between hormones and oxidative stress.
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Affiliation(s)
- Brett M Culbert
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
| | - Shana E Border
- Department of Biology, Central Michigan University, Mount Pleasant, MI, USA; Illinois State University, School of Biological Sciences, Normal, IL, USA
| | | | - Isobel Bolitho
- University of Manchester, Department of Earth and Environmental Sciences, Manchester, UK
| | - Peter D Dijkstra
- Department of Biology, Central Michigan University, Mount Pleasant, MI, USA; Neuroscience Program, Central Michigan University, Mount Pleasant, MI, USA; Institute for Great Lakes Research, Central Michigan University, Mount Pleasant, MI, USA.
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3
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Matsumoto K, Yoshihara K, Katsura C, Ono T, Habara M, Kohda M. Sex-dependent growth regulation in monogamous pairs of a cichlid fish. BEHAVIOUR 2022. [DOI: 10.1163/1568539x-bja10190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
In some social groups, non-breeding subordinates regulate their growth, relative to the size of their immediate dominants in ways that reduce conflict over dominance rank. We predicted that such strategic growth adjustment should also occur in breeding pairs, if this is beneficial for the more subordinate individual within a pair. Using the cichlid fish, Julidochromis transcriptus, held in a laboratory, we examined whether strategic growth regulation occurs in monogamous pairs. In female-largest pairs, smaller males grew slower than their partner when the initial size ratio of pairs (large/small) was small, but faster when the ratio was large, and the number of pairs with an intermediate size ratio increased over time. However, in male-largest pairs, smaller females had a low growth rate and the size ratio of these pairs increased over time. The most important factors for predicting the growth rate of fish were the initial size ratio of pairs for smaller males in female-largest pairs and the initial body size for larger individuals in both pair types, but no such predictors were found for smaller females in male-largest pairs. Neither feeding rate nor attacking rate of the two individuals in a pair predicted the growth rate of smaller fish in a pair. These results suggest that smaller males strategically adjust their own growth, relative to the size of their partner in female-largest pairs, wherein the growth of larger females unrestrained by social relationship with their partner can increase female fecundity, being beneficial for both sexes. The adaptive significance of a low growth rate of smaller females in male-largest pairs is also discussed.
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Affiliation(s)
- Kazunori Matsumoto
- Laboratory of Biology, Faculty of Education, Kagawa University, Takamatsu 760-8522, Japan
| | - Kazuki Yoshihara
- Laboratory of Biology, Faculty of Education, Kagawa University, Takamatsu 760-8522, Japan
| | - Chiyo Katsura
- Laboratory of Biology, Faculty of Education, Kagawa University, Takamatsu 760-8522, Japan
| | - Tatsunori Ono
- Laboratory of Biology, Faculty of Education, Kagawa University, Takamatsu 760-8522, Japan
| | - Masaki Habara
- Laboratory of Biology, Faculty of Education, Kagawa University, Takamatsu 760-8522, Japan
| | - Masanori Kohda
- Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka Metropolitan University, Osaka 558-8585, Japan
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Hamilton IM, Benincasa MD. Emergence of size-structured dominance hierarchies through size-dependent feedback. Philos Trans R Soc Lond B Biol Sci 2022; 377:20200449. [PMID: 35000447 PMCID: PMC8743889 DOI: 10.1098/rstb.2020.0449] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 10/19/2021] [Indexed: 11/24/2022] Open
Abstract
Size-based dominance hierarchies influence fitness, group size and population dynamics and link dominance structure to evolutionary and ecological outcomes. While larger individuals often gain dominance, social status may influence growth and size in return, resulting in feedbacks among status, growth and size. Here, we present two models evaluating how these feedbacks influence the emergence of size structure in a dominance hierarchy. In the first, size influences competition for food and investment in suppressing growth of groupmates. Stable size differences emerged when suppression was greatest for similarly sized individuals and size had little effect on competition for food. The model predicted size divergence when size strongly affected competition for food. In the second model, we used a dynamic game to solve for optimal investment in growth suppression as a function of size structure. Investment in growth suppression was favoured only when dominants and subordinates were similar in size, generating size ratios different than those expected by chance. Variation in the feedbacks among growth, size and status can explain variation in emergent size structure of dominance hierarchies and its consequences for conflict within groups. This article is part of the theme issue 'The centennial of the pecking order: current state and future prospects for the study of dominance hierarchies'.
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Affiliation(s)
- Ian M. Hamilton
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, 318 W 12th Avenue, Columbus, OH 43210, USA
- Department of Mathematics, The Ohio State University, 318 W 12th Avenue, Columbus, OH 43210, USA
| | - Macie D. Benincasa
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, 318 W 12th Avenue, Columbus, OH 43210, USA
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5
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Antioxidant capacity differs across social ranks and with ascension in males of a group-living fish. Comp Biochem Physiol A Mol Integr Physiol 2021; 265:111126. [PMID: 34906630 DOI: 10.1016/j.cbpa.2021.111126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 01/04/2023]
Abstract
Animals that live in groups often form hierarchies in which an individual's behaviour and physiology varies based on their social rank. Occasionally, a subordinate can ascend into a dominant position and the ascending individual must make rapid behavioural and physiological adjustments to solidify their dominance. These periods of social transition and instability can be stressful and ascending individuals often incur large metabolic costs that could influence their oxidative status. Most previous investigations examining the link between oxidative status and the social environment have done so under stable social conditions and have evaluated oxidative status in a single tissue. Therefore, evaluations of how oxidative status is regulated across multiple tissues during periods of social flux would greatly enhance our understanding of the relationship between oxidative status and the social environment. Here, we assessed how antioxidant capacity in three tissues (brain, gonad, and muscle) varied among dominant, subordinate, and ascending males of the group-living cichlid fish, Neolamprologus pulcher. Antioxidant capacity in the brain and muscle of ascending males was intermediate to that of dominant (highest levels) and subordinate males (lowest levels) and correlated with differences in social and locomotor behaviours, respectively. Gonad antioxidant capacity was lower in ascending males than in dominant males. However, gonad antioxidant capacity was positively correlated with the size of ascending males' gonads suggesting that ascending males may increase gonad antioxidant capacity as they develop their gonads. Overall, our results highlight the widespread physiological consequences of social ascension and emphasize the importance of tissue-specific measures of oxidative status.
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Culbert BM, Ligocki IY, Salena MG, Wong MYL, Hamilton IM, Aubin-Horth N, Bernier NJ, Balshine S. Rank- and sex-specific differences in the neuroendocrine regulation of glucocorticoids in a wild group-living fish. Horm Behav 2021; 136:105079. [PMID: 34717080 DOI: 10.1016/j.yhbeh.2021.105079] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 07/27/2021] [Accepted: 10/11/2021] [Indexed: 11/24/2022]
Abstract
Individuals that live in groups experience different challenges based on their social rank and sex. Glucocorticoids have a well-established role in coordinating responses to challenges and glucocorticoid levels often vary between ranks and sexes. However, the neuroendocrine mechanisms regulating glucocorticoid dynamics in wild groups are poorly understood, making it difficult to determine the functional consequences of differences in glucocorticoid levels. Therefore, we observed wild social groups of a cooperatively breeding fish (Neolamprologus pulcher) and evaluated how scale cortisol content (an emerging method to evaluate cortisol dynamics in fishes) and expression of glucocorticoid-related genes varied across group members. Scale cortisol was detectable in ~50% of dominant males (7/17) and females (7/15)-but not in any subordinates (0/16)-suggesting that glucocorticoid levels were higher in dominants. However, the apparent behavioural and neuroendocrine factors regulating cortisol levels varied between dominant sexes. In dominant females, higher cortisol was associated with greater rates of territory defense and increased expression of corticotropin-releasing factor in the preoptic and hypothalamic regions of the brain, but these patterns were not observed in dominant males. Additionally, transcriptional differences in the liver suggest that dominant sexes may use different mechanisms to cope with elevated cortisol levels. While dominant females appeared to reduce the relative sensitivity of their liver to cortisol (fewer corticosteroid receptor transcripts), dominant males appeared to increase hepatic cortisol breakdown (more catabolic enzyme transcripts). Overall, our results offer valuable insights on the mechanisms regulating rank- and sex-based glucocorticoid dynamics, as well as the potential functional outcomes of these differences.
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Affiliation(s)
- Brett M Culbert
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada.
| | - Isaac Y Ligocki
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA; Department of Biology, Millersville University, Millersville, PA, USA
| | - Matthew G Salena
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Marian Y L Wong
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Ian M Hamilton
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH, USA; Department of Mathematics, The Ohio State University, Columbus, OH, USA
| | - Nadia Aubin-Horth
- Département de Biologie and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Quebec, Canada
| | - Nicholas J Bernier
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Sigal Balshine
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
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7
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Abstract
Living in groups affords individuals many benefits, including the opportunity to reduce stress. In mammals, such 'social buffering' of stress is mediated by affiliative relationships and production of the neuropeptide oxytocin, but whether these mechanisms facilitate social buffering across vertebrates remains an open question. Therefore, we evaluated whether the social environment influenced the behavioural and physiological recovery from an acute stressor in a group-living cichlid, Neolamprologus pulcher. Individual fish that recovered with their social group displayed lower cortisol levels than individuals that recovered alone. This social buffering of the stress response was associated with a tendency towards lower transcript abundance of arginine vasotocin and isotocin in the preoptic area of the brain, suggesting reduced neural activation of the stress axis. Individuals that recovered with their social group quickly resumed normal behaviour but received fewer affiliative acts following the stressor. Further experiments revealed similar cortisol levels between individuals that recovered in visual contact with their own social group and those in visual contact with a novel but non-aggressive social group. Collectively, our results suggest that affiliation and familiarity per se do not mediate social buffering in this group-living cichlid, and the behavioural and physiological mechanisms responsible for social buffering may vary across vertebrates.
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Affiliation(s)
- Brett M Culbert
- Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
| | - Kathleen M Gilmour
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, Ontario, Canada K1N 6N5
| | - Sigal Balshine
- Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
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8
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Culbert BM, Gilmour KM, Balshine S. Social buffering of stress in a group-living fish. Proc Biol Sci 2019; 286:20191626. [PMID: 31506060 DOI: 10.5061/dryad.7v93210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Living in groups affords individuals many benefits, including the opportunity to reduce stress. In mammals, such 'social buffering' of stress is mediated by affiliative relationships and production of the neuropeptide oxytocin, but whether these mechanisms facilitate social buffering across vertebrates remains an open question. Therefore, we evaluated whether the social environment influenced the behavioural and physiological recovery from an acute stressor in a group-living cichlid, Neolamprologus pulcher. Individual fish that recovered with their social group displayed lower cortisol levels than individuals that recovered alone. This social buffering of the stress response was associated with a tendency towards lower transcript abundance of arginine vasotocin and isotocin in the preoptic area of the brain, suggesting reduced neural activation of the stress axis. Individuals that recovered with their social group quickly resumed normal behaviour but received fewer affiliative acts following the stressor. Further experiments revealed similar cortisol levels between individuals that recovered in visual contact with their own social group and those in visual contact with a novel but non-aggressive social group. Collectively, our results suggest that affiliation and familiarity per se do not mediate social buffering in this group-living cichlid, and the behavioural and physiological mechanisms responsible for social buffering may vary across vertebrates.
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Affiliation(s)
- Brett M Culbert
- Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
| | - Kathleen M Gilmour
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, Ontario, Canada K1N 6N5
| | - Sigal Balshine
- Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
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9
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Culbert BM, Gilmour KM, Balshine S. Social buffering of stress in a group-living fish. Proc Biol Sci 2019; 286:20191626. [PMID: 31506060 DOI: 10.1098/rspb.2019.1626] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Living in groups affords individuals many benefits, including the opportunity to reduce stress. In mammals, such 'social buffering' of stress is mediated by affiliative relationships and production of the neuropeptide oxytocin, but whether these mechanisms facilitate social buffering across vertebrates remains an open question. Therefore, we evaluated whether the social environment influenced the behavioural and physiological recovery from an acute stressor in a group-living cichlid, Neolamprologus pulcher. Individual fish that recovered with their social group displayed lower cortisol levels than individuals that recovered alone. This social buffering of the stress response was associated with a tendency towards lower transcript abundance of arginine vasotocin and isotocin in the preoptic area of the brain, suggesting reduced neural activation of the stress axis. Individuals that recovered with their social group quickly resumed normal behaviour but received fewer affiliative acts following the stressor. Further experiments revealed similar cortisol levels between individuals that recovered in visual contact with their own social group and those in visual contact with a novel but non-aggressive social group. Collectively, our results suggest that affiliation and familiarity per se do not mediate social buffering in this group-living cichlid, and the behavioural and physiological mechanisms responsible for social buffering may vary across vertebrates.
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Affiliation(s)
- Brett M Culbert
- Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
| | - Kathleen M Gilmour
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, Ontario, Canada K1N 6N5
| | - Sigal Balshine
- Department of Psychology, Neuroscience and Behaviour, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4K1
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