Female-mediated causes and consequences of status change in a social fish

In highly social species, dominant individuals often monopolize reproduction, resulting in reproductive investment that is status dependent. Yet, for subordinates, who typically invest less in reproduction, social status can change and opportunities to ascend to dominant social positions are presented suddenly, requiring abrupt changes in behaviour and physiology. In this study, we examined male reproductive anatomy, physiology and behaviour following experimental manipulations of social status in the cooperatively breeding cichlid fish, Neolamprologus pulcher . This unusual fish species lives in permanent social groups composed of a dominant breeding pair and 1–20 subordinates that form a linear social dominance hierarchy. By removing male breeders, we created 18 breeding vacancies and thus provided an opportunity for subordinate males to ascend in status. Dominant females play an important role in regulating status change, as males successfully ascended to breeder status only when they were slightly larger than the female breeder in their social group. Ascending males rapidly assumed behavioural dominance, demonstrated elevated gonadal investment and androgen concentrations compared with males remaining socially subordinate. Interestingly, to increase gonadal investment ascending males appeared to temporarily restrain somatic growth. These results highlight the complex interactions between social status, reproductive physiology and group dynamics, and underscore a convergent pattern of reproductive investment among highly social, cooperative species.

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Modular genetic control of social status in a cichlid fish

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2008925117 ◽

2020 ◽

Vol 117 (45) ◽

pp. 28167-28174

Author(s):

Beau A. Alward ◽

Vibhav A. Laud ◽

Christopher J. Skalnik ◽

Ryan A. York ◽

Scott A. Juntti ◽

...

Keyword(s):

Social Status ◽

Molecular Mechanisms ◽

Social Systems ◽

Cichlid Fish ◽

Reproductive Behaviors ◽

Modular Control ◽

Social Species ◽

Social Plasticity ◽

Mechanistic Basis

Social hierarchies are ubiquitous in social species and profoundly influence physiology and behavior. Androgens like testosterone have been strongly linked to social status, yet the molecular mechanisms regulating social status are not known. The African cichlid fishAstatotilapia burtoniis a powerful model species for elucidating the role of androgens in social status given their rich social hierarchy and genetic tractability. DominantA. burtonimales possess large testes and bright coloration and perform aggressive and reproductive behaviors while nondominant males do not. Social status inA. burtoniis in flux, however, as males alter their status depending on the social environment. Due to a teleost-specific whole-genome duplication,A. burtonipossess two androgen receptor (AR) paralogs,ARαandARβ, providing a unique opportunity to disentangle the role of gene duplication in the evolution of social systems. Here, we used CRISPR/Cas9 gene editing to generate AR mutantA. burtoniand performed a suite of experiments to interrogate the mechanistic basis of social dominance. We find thatARβ,but notARα, is required for testes growth and bright coloration, whileARα, but notARβ, is required for the performance of reproductive behavior and aggressive displays. Both receptors are required to reduce flees from females and either AR is sufficient for attacking males. Thus, social status inA. burtoniis inordinately dissociable and under the modular control of two AR paralogs. This type of nonredundancy may be important in facilitating social plasticity inA. burtoniand other species whose social status relies on social experience.

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Social Status and Arginine Vasotocin Neuronal Phenotypes in a Cichlid Fish

Brain Behavior and Evolution ◽

10.1159/000381251 ◽

2015 ◽

Vol 85 (3) ◽

pp. 203-213 ◽

Cited By ~ 15

Author(s):

Olinda Almeida ◽

Rui F. Oliveira

Keyword(s):

Social Status ◽

Social Behaviour ◽

Cichlid Fish ◽

Brain Regions ◽

Cell Number ◽

Arginine Vasotocin ◽

Cichlid Species ◽

Neuronal Populations ◽

Soma Size ◽

Species Specific

The nonapeptide arginine vasotocin (AVT) and its mammalian homologue arginine vasopressin play a key role in the regulation of social behaviour across vertebrates. In teleost fishes, three AVT neuronal populations have been described in the preoptic area (POA): the parvocellular (pPOA), the magnocellular (mPOA) and the gigantocellular (gPOA). Neurons from each of these areas project both to the pituitary and to other brain regions, where AVT is supposed to regulate neural circuits underlying social behaviour. However, in the fish species studied so far, there is considerable variation in which AVT neuronal populations are involved in behavioural modulation and in the direction of the effect. In this study, the association between AVT neuronal phenotypes and social status was investigated in the Mozambique tilapia (Oreochromis mossambicus). This species is an African female mouth-brooding cichlid fish in which males form breeding aggregations in which dominant males establish territories and subordinate males to act as floaters. With respect to sex differences in AVT neuronal phenotypes, females have a larger number of AVT neurons in the pPOA and mPOA. Within males, AVT appeared associated with social subordination, as indicated by the larger cell body areas of AVT neurons in mPOA and gPOA nuclei of non-territorial males. There were also positive correlations between submissive behaviour and the soma size of AVT cells in all three nuclei and AVT cell number in the mPOA. In summary, the results provide evidence for an involvement of AVT in the modulation of social behaviour in tilapia, but it was not possible to identify specific roles for specific AVT neuronal populations. The results presented here also contrast with those previously published for another cichlid species with a similar mating system, which highlights the species-specific nature of the pattern of association between AVT and social behaviour even within the same taxonomic family.

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SOCIAL STATUS AND ROMAN RULE - (A.D.) Rizakis, (F.) Camia, (S.) Zoumbaki (edd.) Social Dynamics under Roman Rule. Mobility and Status Change in the Provinces of Achaia and Macedonia. Proceedings of a Conference Held at the French School of Athens, 30–31 May 2014. (Μελετήματα 74.) Pp. 445, ills. Athens: Institute of Historical Research, National Hellenic Research Foundation, 2017. Paper, €30. ISBN: 978-960-9538-63-3.

The Classical Review ◽

10.1017/s0009840x18001944 ◽

2018 ◽

Vol 69 (1) ◽

pp. 210-213

Author(s):

Ligia Ruscu

Keyword(s):

Social Status ◽

Social Dynamics ◽

Historical Research ◽

Status Change ◽

French School ◽

School Of Athens ◽

National Hellenic Research Foundation

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A multidisciplinary study on social status and the relationship between inter-individual variation in hormone levels and agonistic behavior in a Neotropical cichlid fish

Hormones and Behavior ◽

10.1016/j.yhbeh.2015.01.008 ◽

2015 ◽

Vol 69 ◽

pp. 139-151 ◽

Cited By ~ 17

Author(s):

Martín R. Ramallo ◽

Agustina Birba ◽

Renato M. Honji ◽

Leonel Morandini ◽

Renata G. Moreira ◽

...

Keyword(s):

Social Status ◽

Individual Variation ◽

Agonistic Behavior ◽

Cichlid Fish ◽

Hormone Levels ◽

Multidisciplinary Study ◽

The Relationship

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Cultural and reproductive success in industrial societies: Testing the relationship at the proximate and ultimate levels

Behavioral and Brain Sciences ◽

10.1017/s0140525x00029939 ◽

1993 ◽

Vol 16 (2) ◽

pp. 267-283 ◽

Cited By ~ 282

Author(s):

Daniel Pérusse

Keyword(s):

Reproductive Success ◽

Social Status ◽

Human Behavior ◽

Industrial Society ◽

Human Populations ◽

Social Species ◽

Traditional Societies ◽

Highly Correlated ◽

Underlying Mechanisms ◽

The One

AbstractIn most social species, position in the male social hierarchy and reproductive success are positively correlated; in humans, however, this relationship is less clear, with studies of traditional societies yielding mixed results. In the most economically advanced human populations, the adaptiveness of status vanishes altogether; social status and fertility are uncorrelated. These findings have been interpreted to suggest that evolutionary principles may not be appropriate for the explanation of human behavior, especially in modern environments. The present study tests the adaptiveness of social status with actual mating and reproductive data in a representative sample of males from an industrial society. Reproductive success, even when assessed by a more reliable measure ofactualmale fertility than the one commonly used, fails to correlate with social status. In striking contrast, however, status is found to be highly correlated withpotentialfertility, as estimated from copulation frequency. Status thus accounts for as much as 62% of the variance in thisproximatecomponent of fitness. This pattern is remarkably similar to what is found in many traditional societies and would result in a substantial positive relationship between cultural and reproductive success in industrial populations were it not for the novel conditions imposed by contraception and monogamy. Various underlying mechanisms are suggested for these findings, illustrating the value of current behavioral and reproductive data in the study of adaptation. It is concluded that evolutionary explanations of human behavior remain entirely relevant in modern societies.

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Strategic and tactical fighting decisions in cichlid fishes with divergent social systems

Behaviour ◽

10.1163/1568539x-00003122 ◽

2014 ◽

Vol 151 (1) ◽

pp. 47-71 ◽

Cited By ~ 19

Author(s):

Kristina Hick ◽

Adam R. Reddon ◽

Constance M. O’Connor ◽

Sigal Balshine

Keyword(s):

Social Systems ◽

Cichlid Fish ◽

Group Living ◽

Social Situation ◽

Closely Related Species ◽

Social Species ◽

Hierarchy Formation ◽

Trade Offs ◽

The Social ◽

Contest Behaviour

The costs and benefits of engaging in a contest will differ depending on the social situation of the individuals involved. Therefore, understanding contest behaviour can help to elucidate the trade-offs of living in differing social systems and shed light on the evolution of social behaviour. In the current study, we compared contest behaviour in two closely related species of Lamprologine cichlid fish. Neolamprologus pulcher and Telmatochromis temporalis are both pair-breeding cichlids, but N. pulcher are highly social, group-living fish, while T. temporalis display no grouping behaviour. To examine how competition varies by species, sex and familiarity, we staged same-sex conspecific contests over a shelter, a resource that is highly valued by both species, where contestants were either familiar or unfamiliar to one another. When we examined tactical and strategic components of these contests, we found that the highly social species had shorter contests and engaged in fewer costly aggressive acts than did the non-social species. Individuals of the highly social species were also more likely to resolve conflicts through the use of submissive displays, while individuals of the non-social species were more likely to flee from conflict. Familiarity increased the use of submissive displays in the highly social species but not in the less social species. Our findings suggest that conflict resolution behaviour and dominance hierarchy formation are fundamentally linked to the evolution of complex social systems.

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Hormonal control of brood care and social status in a cichlid fish with brood care helpers

Physiology & Behavior ◽

10.1016/j.physbeh.2008.02.002 ◽

2008 ◽

Vol 94 (3) ◽

pp. 349-358 ◽

Cited By ~ 32

Author(s):

Nicole Bender ◽

Zina Heg-Bachar ◽

Rui F. Oliveira ◽

Adelino V.M. Canario ◽

Michael Taborsky

Keyword(s):

Social Status ◽

Cichlid Fish ◽

Hormonal Control ◽

Brood Care

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A complex mode of aggressive mimicry in a scale-eating cichlid fish

Biology Letters ◽

10.1098/rsbl.2015.0521 ◽

2015 ◽

Vol 11 (9) ◽

pp. 20150521 ◽

Cited By ~ 11

Author(s):

Nicolas Boileau ◽

Fabio Cortesi ◽

Bernd Egger ◽

Moritz Muschick ◽

Adrian Indermaur ◽

...

Keyword(s):

Fish Species ◽

Related Species ◽

Lake Tanganyika ◽

Cichlid Fish ◽

Targeted Sequencing ◽

Complex Mode ◽

Cichlid Species ◽

Aggressive Mimicry ◽

Complex Interactions

Aggressive mimicry is an adaptive tactic of parasitic or predatory species that closely resemble inoffensive models in order to increase fitness via predatory gains. Although similarity of distantly related species is often intuitively implicated with mimicry, the exact mechanisms and evolutionary causes remain elusive in many cases. Here, we report a complex aggressive mimicry strategy in Plecodus straeleni , a scale-eating cichlid fish from Lake Tanganyika, which imitates two other cichlid species. Employing targeted sequencing on ingested scales, we show that P. straeleni does not preferentially parasitize its models but—contrary to prevailing assumptions—targets a variety of co-occurring dissimilar looking fish species . Combined with tests for visual resemblance and visual modelling from a prey perspective, our results suggest that complex interactions among different cichlid species are involved in this mimicry system.

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Plasticity of the Reproductive Axis Caused by Social Status Change in an African Cichlid Fish: II. Testicular Gene Expression and Spermatogenesis

Endocrinology ◽

10.1210/en.2010-0876 ◽

2011 ◽

Vol 152 (1) ◽

pp. 291-302 ◽

Cited By ~ 43

Author(s):

Karen P. Maruska ◽

Russell D. Fernald

Keyword(s):

Gene Expression ◽

Social Environment ◽

Steroid Receptors ◽

Cichlid Fish ◽

Reproductive Capacity ◽

Receptor Subtypes ◽

Mrna Levels ◽

Status Change ◽

African Cichlid ◽

Reproductive Axis

Abstract Reproduction in all vertebrates is controlled by the brain-pituitary-gonad (BPG) axis, which is regulated socially in males of the African cichlid fish Astatotilapia burtoni. Although social information influences GnRH1 neurons at the apex of the BPG axis, little is known about how the social environment and dominance affects the cellular and molecular composition of the testes to regulate reproductive capacity. We created an opportunity for reproductively suppressed males to ascend in status and then measured changes in gene expression and tissue morphology to discover how quickly the perception of this opportunity can influence the testes. Our results show rapid up-regulation of mRNA levels of FSH receptor and several steroid receptor subtypes in the testes during social ascent. In contrast, LH receptor was not elevated until 72 h after ascent, but this increase was coincident with elevated circulating androgens and early stages of spermatogenesis, suggesting a role in steroidogenesis. The spermatogenic potential of the testes, as measured by cellular composition, was also elevated before the overall increase in testes size. The presence of cysts at all stages of spermatogenesis, coupled with lower levels of gonadotropin and steroid receptors in subordinate males, suggests that the BPG axis and spermatogenesis are maintained at a subthreshold level in anticipation of the chance to gain a territory and become reproductively active. Our results show that the testis is stimulated extremely quickly after perception of social opportunity, presumably to allow suppressed males to rapidly achieve high reproductive success in a dynamic social environment.

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