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Kobayashi T, Kohda M, Awata S, Bshary R, Sogawa S. Cleaner fish with mirror self-recognition capacity precisely realize their body size based on their mental image. Sci Rep 2024; 14:20202. [PMID: 39261520 DOI: 10.1038/s41598-024-70138-7] [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: 05/16/2024] [Accepted: 08/13/2024] [Indexed: 09/13/2024] Open
Abstract
Animals exhibiting mirror self-recognition (MSR) are considered self-aware; however, studies on their level of self-awareness remain inconclusive. Recent research has indicated the potential for cleaner fish (Labroides dimidiatus) to possess a sophisticated level of private self-awareness. However, as this study revealed only an aspect of private self-awareness, further investigation into other elements is essential to substantiate this hypothesis. Here, we show that cleaner fish, having attained MSR, construct a mental image of their bodies by investigating their ability to recall body size. A size-based hierarchy governs the outcomes of their confrontations. The mirror-naïve fish behaved aggressively when presented with photographs of two unfamiliar conspecifics that were 10% larger and 10% smaller than their body sizes. After passing the MSR test, they refrained from aggression toward the larger photographs but still behaved aggressively toward the smaller ones without re-examining their mirror images. These findings suggest that cleaner fish accurately recognize their body size based on mental images of their bodies formed through MSR. Additionally, mirror-experienced fish frequently revisited the mirror when presented with an intimidating larger photograph, implying the potential use of mirrors for assessing body size. Our study established cleaner fish as the first non-human animal to be demonstrated to possess private self-awareness.
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Affiliation(s)
- Taiga Kobayashi
- Laboratory of Animal Sociology, Department of Biology, Graduate School of Science, Osaka Metropolitan University, Osaka, Japan.
- Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan.
| | - Masanori Kohda
- Laboratory of Animal Sociology, Department of Biology, Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
- Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan
| | - Satoshi Awata
- Laboratory of Animal Sociology, Department of Biology, Graduate School of Science, Osaka Metropolitan University, Osaka, Japan
- Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan
| | - Redouan Bshary
- Institute of Zoology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Shumpei Sogawa
- Laboratory of Animal Sociology, Department of Biology, Graduate School of Science, Osaka Metropolitan University, Osaka, Japan.
- Laboratory of Animal Sociology, Department of Biology and Geosciences, Graduate School of Science, Osaka City University, Osaka, Japan.
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2
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Alex D, Cardoso SD, Ramos A, Gonçalves D. Behavioral and endocrine responses to noninteractive live and video conspecifics in males of the Siamese fighting fish. Curr Zool 2023; 69:568-577. [PMID: 37637314 PMCID: PMC10449422 DOI: 10.1093/cz/zoac078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 09/26/2022] [Indexed: 08/29/2023] Open
Abstract
The physiological mechanisms underlying variation in aggression in fish remain poorly understood. One possibly confounding variable is the lack of standardization in the type of stimuli used to elicit aggression. The presentation of controlled stimuli in videos, a.k.a. video playback, can provide better control of the fight components. However, this technique has produced conflicting results in animal behavior studies and needs to be carefully validated. For this, a similar response to the video and an equivalent live stimulus needs to be demonstrated. Further, different physiological responses may be triggered by live and video stimuli, and it is important to demonstrate that video images elicit appropriate physiological reactions. Here, the behavioral and endocrine responses of male Siamese fighting fish Betta splendens to a matched-for-size conspecific fighting behind a one-way mirror, presented live or through video playback, were compared. The video playback and live stimulus elicited a strong and similar aggressive response by the focal fish, with a fight structure that started with stereotypical threat displays and progressed to overt attacks. Postfight plasma levels of the androgen 11-ketotestosterone were elevated as compared to controls, regardless of the type of stimuli. Cortisol also increased in response to the video images, as previously described for live fights in this species. These results show that the interactive component of a fight and its resolution are not needed to trigger an endocrine response to aggression in this species. The study also demonstrates for the first time in a fish a robust endocrine response to video stimuli and supports the use of this technique for researching aggressive behavior in B. splendens.
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Affiliation(s)
- Deepa Alex
- Institute of Science and Environment, University of Saint Joseph, Rua de Londres 106, Macao SAR, China
| | - Sara D Cardoso
- Institute of Science and Environment, University of Saint Joseph, Rua de Londres 106, Macao SAR, China
| | - Andreia Ramos
- Institute of Science and Environment, University of Saint Joseph, Rua de Londres 106, Macao SAR, China
| | - David Gonçalves
- Institute of Science and Environment, University of Saint Joseph, Rua de Londres 106, Macao SAR, China
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3
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Axling J, Vossen LE, Peterson E, Winberg S. Boldness, activity, and aggression: Insights from a large-scale study in Baltic salmon (Salmo salar L). PLoS One 2023; 18:e0287836. [PMID: 37471414 PMCID: PMC10358900 DOI: 10.1371/journal.pone.0287836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 06/14/2023] [Indexed: 07/22/2023] Open
Abstract
Atlantic salmon (Salmo salar) display high levels of agonistic behavior in aquaculture farms, resulting in fin damage and chronic stress. Aggression affects fish growth and performance negatively, and presents a serious welfare problem. Indeed, it would be beneficial to identify, separate or exclude overly aggressive individuals. Research on behavioral syndromes suggests that aggressive behavior may correlate with other behavioral traits, such as boldness and locomotory activity. We aimed to develop a high-throughput method to quantify and predict aggressive behavior of individual parr in hatchery-reared Baltic salmon (Salmo salar L.). We screened approximately 2000 parr in open field (OF) and mirror image stimulation (MIS) tests. We extracted seven variables from video tracking software for each minute of the tests; distance moved and duration moving (activity), the duration in and number of entries to the center of the arena (boldness), the distance moved in and duration spent in the area adjacent to the mirror during the MIS test (aggressiveness) and head direction (lateralization). To investigate the relationship between activity, boldness and aggression we first correlated the first six variables to one another. Second, we assigned individuals to high, medium, low or zero aggression groups based on the MIS test and quantified activity and boldness in each group. Third, we analyzed whether the fish viewed the mirror with the left or right eye. Our results show that medium and low aggressive fish were the most active, while highly aggressive fish showed average activity. Aggressive groups did not differ in boldness. Activity and boldness were positively correlated. Finally, we detected a preference for fish to view the mirror with the left eye. We conclude that aggressiveness cannot be predicted from the results of the OF test alone but that the MIS test can be used for large-scale individual aggression profiling of juvenile salmon.
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Affiliation(s)
- Johanna Axling
- Behavioural Neuroendocrinology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Behavioural Neuroendocrinology, Department of Neuroscience, Uppsala University, Uppsala, Sweden
| | - Laura E. Vossen
- Division of Anatomy and Physiology, Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Erik Peterson
- Department of Aquatic Resources, Swedish University of Agriculture, Uppsala, Sweden
| | - Svante Winberg
- Behavioural Neuroendocrinology, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Behavioural Neuroendocrinology, Department of Neuroscience, Uppsala University, Uppsala, Sweden
- Division of Anatomy and Physiology, Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
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4
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Oliveira JA, da Silva Souza JG, de Jesus Paula DA, Carmo Rodrigues Virote BD, Murgas LDS. Oxytocin reduces the frequency of aggressive behaviours in male betta fish (Betta splendens). Behav Processes 2022; 200:104689. [PMID: 35718243 DOI: 10.1016/j.beproc.2022.104689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 11/16/2022]
Abstract
The objective of this study was to evaluate the effect of visual isolation and the influence of oxytocin on the aggressive behaviour of male Betta splendens and produce an ethogram for analyses. In the first stage, the fish (n=6) were kept for 60 days in a recirculation system, maintaining visual contact. After this period, the mirror test was applied. The same procedure was performed with the same individuals after 30 days of visual isolation. Visual isolation did no effect on the aggressive behaviour. Application of oxytocin (2.5µg/g) for 1h (twice) in this first stage was also conducted after the mirror test. The effect of exposure to oxytocin was evaluated by applying the mirror test 24hours after the second exposure. The second stage was conducted with another 10 individuals exposed to oxytocin (7.5µg/g) for 1h, after which the mirror test was performed. Exposure to oxytocin (2.5µg/g) did not effect on combat-related behaviours. However, in the second stage influenced all behaviours related to combat and display, with an increase in the frequency of "rest" behaviour. The results indicate that exposure to a neuropeptide at a dose of 7.5µg/g reduces the frequency of aggressive behaviour of male Betta splendens.
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Affiliation(s)
- Júlia Alvarenga Oliveira
- Department of Biology, Natural Sciences Institute of Federal University of Lavras, UFLA, Rua Doutor Silvio Menicucci, s/n, Lavras 37200-900, Minas Gerais, Brazil
| | - José Gilmar da Silva Souza
- Department of Animal Science, College of Animal Science and Veterinary Medicine of Federal University of Lavras, UFLA, Rua Doutor Silvio Menicucci, s/n, Lavras 37200-900, Minas Gerais, Brazil
| | - Daniella Aparecida de Jesus Paula
- Postgraduate Program in Veterinary Medicine, College of Animal Science and Veterinary Medicine of Federal University of Lavras, UFLA, Rua Doutor Silvio Menicucci, s/n, Lavras 37200-900, Minas Gerais, Brazil.
| | - Bárbara do Carmo Rodrigues Virote
- Postgraduate Program in Veterinary Medicine, College of Animal Science and Veterinary Medicine of Federal University of Lavras, UFLA, Rua Doutor Silvio Menicucci, s/n, Lavras 37200-900, Minas Gerais, Brazil
| | - Luis David Solis Murgas
- Postgraduate Program in Veterinary Medicine, College of Animal Science and Veterinary Medicine of Federal University of Lavras, UFLA, Rua Doutor Silvio Menicucci, s/n, Lavras 37200-900, Minas Gerais, Brazil.
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5
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Hubená P, Horký P, Slavík O. Fish self-awareness: limits of current knowledge and theoretical expectations. Anim Cogn 2021; 25:447-461. [PMID: 34655023 DOI: 10.1007/s10071-021-01566-5] [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: 02/25/2021] [Revised: 09/15/2021] [Accepted: 10/08/2021] [Indexed: 10/20/2022]
Abstract
Animal self-awareness is divided into three levels: bodily, social, and introspective self-awareness. Research has focused mainly on the introspection of so-called higher organisms such as mammals. Herein, we turn our attention to fish and provide opinions on their self-awareness based on a review of the scientific literature. Our specific aims are to discuss whether fish (A) could have a neural substrate supporting self-awareness and whether they display signs of (B) social and (C) introspective self-awareness. The present knowledge does not exclude the possibility that fish could have a simple neocortex or other structures that support certain higher cognitive processes, as the function of the primate cerebral cortex can be replaced by other neurological structures. Fish are known to display winner, loser, and audience effects, which could be interpreted as signs of social self-awareness. The audience effect may be explained not only by ethological cost and benefit theory but also by the concept of public self-awareness, which comes from human studies. The behavioural and neural manifestations of depression may be induced in fish under social subordination and may be viewed as certain awareness of a social status. The current findings on fish introspective self-awareness have been debated in the scientific community and, therefore, demand replication to provide more evidence. Further research is needed to verify the outlined ideas; however, the current knowledge indicates that fish are capable of certain higher cognitive processes, which raises questions and implications regarding ethics and welfare in fish-related research and husbandry.
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Affiliation(s)
- Pavla Hubená
- Department of Zoology and Fisheries, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, 165 00, Suchdol, Czech Republic.
| | - Pavel Horký
- Department of Zoology and Fisheries, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, 165 00, Suchdol, Czech Republic
| | - Ondřej Slavík
- Department of Zoology and Fisheries, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6, 165 00, Suchdol, Czech Republic
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6
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Josi D, Frommen JG. Through a glass darkly? Divergent reactions of eight Lake Tanganyika cichlid species towards their mirror image in their natural environment. Ethology 2021. [DOI: 10.1111/eth.13207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dario Josi
- Department of Natural Sciences Ecology and Environment Research Centre Conservation, Ecology, Evolution and Behaviour Research Group Manchester Metropolitan University Manchester UK
- Institute of Ecology and Evolution Division of Behavioural Ecology University of Bern Hinterkappelen Switzerland
| | - Joachim G. Frommen
- Department of Natural Sciences Ecology and Environment Research Centre Conservation, Ecology, Evolution and Behaviour Research Group Manchester Metropolitan University Manchester UK
- Institute of Ecology and Evolution Division of Behavioural Ecology University of Bern Hinterkappelen Switzerland
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7
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Kua ZX, Hamilton IM, McLaughlin AL, Brodnik RM, Keitzer SC, Gilliland J, Hoskins EA, Ludsin SA. Water warming increases aggression in a tropical fish. Sci Rep 2020; 10:20107. [PMID: 33208894 PMCID: PMC7676273 DOI: 10.1038/s41598-020-76780-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 11/02/2020] [Indexed: 11/09/2022] Open
Abstract
Our understanding of how projected climatic warming will influence the world's biota remains largely speculative, owing to the many ways in which it can directly and indirectly affect individual phenotypes. Its impact is expected to be especially severe in the tropics, where organisms have evolved in more physically stable conditions relative to temperate ecosystems. Lake Tanganyika (eastern Africa) is one ecosystem experiencing rapid warming, yet our understanding of how its diverse assemblage of endemic species will respond is incomplete. Herein, we conducted a laboratory experiment to assess how anticipated future warming would affect the mirror-elicited aggressive behaviour of Julidochromis ornatus, a common endemic cichlid in Lake Tanganyika. Given linkages that have been established between temperature and individual behaviour in fish and other animals, we hypothesized that water warming would heighten average individual aggression. Our findings support this hypothesis, suggesting the potential for water warming to mediate behavioural phenotypic expression through negative effects associated with individual health (body condition). We ultimately discuss the implications of our findings for efforts aimed at understanding how continued climate warming will affect the ecology of Lake Tanganyika fishes and other tropical ectotherms.
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Affiliation(s)
- Zi Xun Kua
- Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Road, Columbus, OH, 43212, USA
- Department of Sustainable Resources Management, College of Environmental Science and Forestry, State University of New York, 1 Forestry Drive, Syracuse, NY, 13210, USA
| | - 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
| | - Allison L McLaughlin
- Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Road, Columbus, OH, 43212, USA
- Department of Biology, University of Kentucky, 101 T.H. Morgan Building, Lexington, KY, 40506, USA
| | - Reed M Brodnik
- Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Road, Columbus, OH, 43212, USA
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, 146 Williams St., Solomons, MD, 20688, USA
| | - S Conor Keitzer
- Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Road, Columbus, OH, 43212, USA
- Department of Natural Science, Tusculum University, Greenville, TN, 37745, USA
| | - Jake Gilliland
- Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Road, Columbus, OH, 43212, USA
- Nationwide Children's Hospital, Columbus, OH, 43205, USA
| | - Elizabeth A Hoskins
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 318 W 12th Avenue, Columbus, OH, 43210, USA
| | - Stuart A Ludsin
- Aquatic Ecology Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, 1314 Kinnear Road, Columbus, OH, 43212, USA.
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8
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Performance of cyprinids in non-reversing mirrors versus regular mirrors in tests of aggressiveness. J ETHOL 2020. [DOI: 10.1007/s10164-020-00679-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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9
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Hubená P, Horký P, Slavík O. Test-dependent expression of behavioral syndromes: A study of aggressiveness, activity, and stress of chub. Aggress Behav 2020; 46:412-424. [PMID: 32542801 DOI: 10.1002/ab.21909] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 05/19/2020] [Accepted: 06/04/2020] [Indexed: 11/09/2022]
Abstract
Aggressiveness has been one of the behavioral traits most examined with various standard testing methods. We used two distinct methods (the mirror and the real opponent tests) to evaluate individual aggression and relate it to the activity and individual stress of chub (Squalius cephalus L.). Three hypotheses were formulated and tested: (a) there is a significant positive relationship between the aggressiveness of individuals measured with the mirror and the real opponent tests, indicating their convergent validity; (b) the irregularities in response to the aggressiveness and activity tests lead to the context-specific expression of the behavioral syndromes; and (c) there is a significant positive relationship between the stress induced in individuals by both tests of aggressiveness, demonstrating individually consistent stress-coping strategies. The first and the second hypothesis were confirmed, while the third hypothesis was rejected. Our results suggest that particular tests of aggressiveness could act as a situation with high strength, leaving little variation between individual responses. Thus, we propose that for the proper interpretation of various studies using different tests to study identical behavioral traits, it is important to consider the convergent validity of not only the tested behavioral traits but also the individual stress responses. The chub also showed stress relieve through aggressiveness, suggesting the species as a prospective animal model to the study interaction between the stress and the aggressiveness. A detailed aggression ethogram of chub was provided to facilitate the use of this specie in future studies.
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Affiliation(s)
- Pavla Hubená
- Department of Zoology and FisheriesCzech University of Life Sciences Prague Prague Suchdol Czech Republic
| | - Pavel Horký
- Department of Zoology and FisheriesCzech University of Life Sciences Prague Prague Suchdol Czech Republic
| | - Ondřej Slavík
- Department of Zoology and FisheriesCzech University of Life Sciences Prague Prague Suchdol Czech Republic
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10
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Baran NM, Streelman JT. Ecotype differences in aggression, neural activity and behaviorally relevant gene expression in cichlid fish. GENES BRAIN AND BEHAVIOR 2020; 19:e12657. [PMID: 32323443 DOI: 10.1111/gbb.12657] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/17/2020] [Accepted: 04/18/2020] [Indexed: 12/18/2022]
Abstract
In Lake Malawi, two ecologically distinct lineages of cichlid fishes (rock- vs sand-dwelling ecotypes, each comprised of over 200 species) evolved within the last million years. The rock-dwelling species (Mbuna) are aggressively territorial year-round and males court and spawn with females over rocky substrate. In contrast, males of sand-dwelling species are not territorial and instead aggregate on seasonal breeding leks in which males construct courtship "bowers" in the sand. However, little is known about how phenotypic variation in aggression is produced by the genome. In this study, we first quantify and compare behavior in seven cichlid species, demonstrating substantial ecotype and species differences in unconditioned mirror-elicited aggression. Second, we compare neural activity in mirror-elicited aggression in two representative species, Mchenga conophoros (sand-dwelling) and Petrotilapia chitimba (rock-dwelling). Finally, we compare gene expression patterns between these two species, specifically within neurons activated during mirror aggression. We identified a large number of genes showing differential expression in mirror-elicited aggression, as well as many genes that differ between ecotypes. These genes, which may underly species differences in behavior, include several neuropeptides, genes involved in the synthesis of steroid hormones and neurotransmitter activity. This work lays the foundation for future experiments using this emerging genetic model system to investigate the genomic basis of evolved species differences in both brain and behavior.
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Affiliation(s)
- Nicole M Baran
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA.,Department of Psychology, Emory University, Atlanta, Georgia, USA
| | - J Todd Streelman
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA.,The Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA
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11
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Martin CH, McGirr JA, Richards EJ, St. John ME. How to Investigate the Origins of Novelty: Insights Gained from Genetic, Behavioral, and Fitness Perspectives. Integr Org Biol 2019; 1:obz018. [PMID: 33791533 PMCID: PMC7671130 DOI: 10.1093/iob/obz018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Biologists are drawn to the most extraordinary adaptations in the natural world, often referred to as evolutionary novelties, yet rarely do we understand the microevolutionary context underlying the origins of novel traits, behaviors, or ecological niches. Here we discuss insights gained into the origins of novelty from a research program spanning biological levels of organization from genotype to fitness in Caribbean pupfishes. We focus on a case study of the origins of novel trophic specialists on San Salvador Island, Bahamas and place this radiation in the context of other rapid radiations. We highlight questions that can be addressed about the origins of novelty at different biological levels, such as measuring the isolation of novel phenotypes on the fitness landscape, locating the spatial and temporal origins of adaptive variation contributing to novelty, detecting dysfunctional gene regulation due to adaptive divergence, and connecting behaviors with novel traits. Evolutionary novelties are rare, almost by definition, and we conclude that integrative case studies can provide insights into this rarity relative to the dynamics of adaptation to more common ecological niches and repeated parallel speciation, such as the relative isolation of novel phenotypes on fitness landscapes and the transient availability of ecological, genetic, and behavioral opportunities.
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Affiliation(s)
- C H Martin
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - J A McGirr
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
| | - E J Richards
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - M E St. John
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
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12
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Ramos A, Gonçalves D. Artificial selection for male winners in the Siamese fighting fish Betta splendens correlates with high female aggression. Front Zool 2019; 16:34. [PMID: 31406496 PMCID: PMC6686523 DOI: 10.1186/s12983-019-0333-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/29/2019] [Indexed: 11/10/2022] Open
Abstract
In Southeast Asia, males of the Siamese fighting fish Betta splendens have been selected across centuries for paired-staged fights. During the selection process, matched for size males fight in a small tank until the contest is resolved. Breeders discard losing batches and reproduce winner batches with the aim of increasing fight performance. We assessed the results of this long-term selection process by comparing under standard laboratory conditions male and female aggressive behaviour of one strain selected for staged fights ("fighters") and one strain of wild-types. The aggressive response of adult fish was tested against their mirror image or a size-matched conspecific. Fighter males were more aggressive than wild-type males for all measured behaviours. Differences were not only quantitative but the pattern of fight display was also divergent. Fighter males had an overall higher swimming activity, performing frequent fast strikes in the direction of the intruder and displaying from a distance. Wild-type males were less active and exhibited aggressive displays mostly in close proximity to the stimuli. Females of the fighter strain, which are not used for fights, were also more aggressive than wild-type females. Aggressive behaviours were correlated across male and female fighter siblings, suggesting common genetic and physiological mechanisms to male and female aggression in this species. The study further shows that results were largely independent of the stimulus type, with the mirror test inducing similar and less variable responses than the live conspecific presentation. These results suggest that selection for male winners co-selected for high-frequency and metabolic demanding aggressive display in males and also enhanced female aggression, opening a wide range of testable hypothesis about the ultimate and proximate mechanisms of male and female aggression in B. splendens.
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Affiliation(s)
- A. Ramos
- Institute of Science and Environment, University of Saint Joseph, Rua de Londres 16, Macao, China
| | - D. Gonçalves
- Institute of Science and Environment, University of Saint Joseph, Rua de Londres 16, Macao, China
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13
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Li CY, Jones R, Earley RL. Contest decisions are governed by own size and opponent size category in mangrove rivulus fish, Kryptolebias marmoratus. Anim Behav 2018. [DOI: 10.1016/j.anbehav.2018.09.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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14
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Li CY, Hofmann HA, Harris ML, Earley RL. Real or fake? Natural and artificial social stimuli elicit divergent behavioural and neural responses in mangrove rivulus, Kryptolebias marmoratus. Proc Biol Sci 2018; 285:rspb.2018.1610. [PMID: 30429304 DOI: 10.1098/rspb.2018.1610] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/26/2018] [Indexed: 11/12/2022] Open
Abstract
Understanding how the brain processes social information and generates adaptive behavioural responses is a major goal in neuroscience. We examined behaviour and neural activity patterns in socially relevant brain nuclei of hermaphroditic mangrove rivulus fish (Kryptolebias marmoratus) provided with different types of social stimuli: stationary model opponent, regular mirror, non-reversing mirror and live opponent. We found that: (i) individuals faced with a regular mirror were less willing to interact with, delivered fewer attacks towards and switched their orientation relative to the opponent more frequently than fish exposed to a non-reversing mirror image or live opponent; (ii) fighting with a regular mirror image caused higher expression of immediate-early genes (IEGs: egr-1 and c-Fos) in the teleost homologues of the basolateral amygdala and hippocampus, but lower IEG expression in the preoptic area, than fighting with a non-reversing mirror image or live opponent; (iii) stationary models elicited the least behavioural and IEG responses among the four stimuli; and (iv) the non-reversing mirror image and live opponent drove similar behavioural and neurobiological responses. These results suggest that the various stimuli provide different types of information related to conspecific recognition in the context of aggressive contests, which ultimately drive different neurobiological responses.
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Affiliation(s)
- Cheng-Yu Li
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
| | - Hans A Hofmann
- Department of Integrative Biology, Institute for Cellular and Molecular Biology, Institute for Neuroscience, The University of Texas, Austin, TX 78712, USA
| | - Melissa L Harris
- Department of Biological Sciences, University of Alabama, Birmingham, AL 35294, USA
| | - Ryan L Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
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