Extra-gonadal steroids modulate non-breeding territorial aggression in weakly electric fish

Jalabert, Cecilia; Quintana, Laura; Pessina, Paula; Silva, Ana C.

doi:10.1016/j.yhbeh.2015.05.003

Cited by 43 publications

(44 citation statements)

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“…Gymnotus omarorum (Richer-de-Forges et al, 2009 ) displays a clear-cut example of pure territorial aggression (Batista et al, 2012 ; Silva et al, 2013 ; Jalabert et al, 2015 ; Zubizarreta et al, 2015 ; Quintana et al, 2016 ). During the non-breeding season, when gonads are regressed, and no reproductive motivation is expected to drive competition, males and females of this sexually monomorphic species fiercely defend territories in intrasexual and intersexual dyadic encounters.…”

Section: Introductionmentioning

confidence: 99%

Status-Dependent Vasotocin Modulation of Dominance and Subordination in the Weakly Electric Fish Gymnotus omarorum

Perrone

Silva

2018

Front. Behav. Neurosci.

106

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Dominant-subordinate status emerges from agonistic encounters. The weakly electric fish, Gymnotus omarorum, displays a clear-cut example of non-breeding territorial aggression. The asymmetry in the behavior of dominants and subordinates is outstanding. Dominants are highly aggressive and subordinates signal submission in a precise sequence of locomotor and electric traits: retreating, decreasing their electric organ discharge rate, and emitting transient electric signals. The hypothalamic neuropeptide arginine-vasotocin (AVT) and its mammalian homolog arginine-vasopressin, are key modulators of social behavior, known to adapt their actions to different contexts. By analyzing the effects of pharmacological manipulations of the AVT system in both dominants and subordinates, we show evidence of distinct status-dependent actions of AVT. We demonstrate an endogenous effect of AVT on dominants' aggression levels: blocking the V1a AVT receptor induced a significant decrease in dominants' attack rate. AVT administered to subordinates enhanced the expression of the electric signals of submission, without affecting subordinates' locomotor displays. This study contributes a clear example of status-dependent AVT modulation of agonistic behavior in teleosts, and reveals distinctive activation patterns of the AVT system between dominants and subordinates.

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Section: Introductionmentioning

confidence: 99%

Status-Dependent Vasotocin Modulation of Dominance and Subordination in the Weakly Electric Fish Gymnotus omarorum

Perrone

Silva

2018

Front. Behav. Neurosci.

106

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“…Under experimental laboratory conditions, male-male and female-female dyads that display non-breeding territorial behavior have shown no differences in either contest outcome, temporal dynamics of the agonistic encounter, levels of aggression, nor submissive signaling (39). Moreover, the only significant predictor of contest outcome is body size (22), and none of the features of agonistic encounters depends on circulating gonadal hormones (40).…”

Section: Introductionmentioning

confidence: 99%

Seasonal and social factors associated with spacing in a wild territorial electric fish

Zubizarreta

Quintana

Hernández³

et al. 2020

Preprint

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29The expression of territorial behavior in wild species is especially suited to explore how 30 animals integrate individual traits with dynamic environmental and social contexts. In this 31 study, we focused on the seasonal variation of the determinants of territory size in the weakly 32 electric fish Gymnotus omarorum. This species is a seasonal breeder that displays year-33 long territorial aggression, in which female and male dyads exhibit indistinguishable non-34 breeding territorial agonistic behavior and the only significant predictor of contest outcome 35 is body size. We carried out field surveys across seasons that included the identification of 36 individual location, measurements of water physico-chemical variables, characterization of 37 individual morphometric and physiological traits, and their correlation to spatial distribution. 38Although Gymnotus omarorum tolerates a wide range of dissolved oxygen concentration, 39 territory size correlated with dissolved oxygen in both seasons. In the non-breeding season, 40we show that territory size is sexually monomorphic and explained only by body size. In the 41 breeding season, while body size no longer correlated with territory size, evidence of sexual 42 differences in territory size determinants emerged. First, the overall spatial arrangement 43 adopted a sexual bias. Second, territory size depended on gonadal hormones in both sexes, 44which was expected for males, but not previously reported in females. Third, females' 45 territory size correlated with gonadal size and females showed relatively larger territories 46 than males, probably to meet sexually dimorphic energetic requirements. This study 47 provides evidence of seasonal changes in factors correlated with territory size and 48 contributes to the understanding of the mechanisms underlying behavioral plasticity. 49 50 Keywords 51 Non-breeding aggression, sexual dimorphism, Gymnotus omarorum, gonadal steroids 3 52 53

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“…Naturally occurring, social role-associated variation in levels of aromatase (the enzyme that converts testosterone into estradiol) regulates aggression in the cichlid Astatotilapia burtoni 30 . In the teleost fish Gymnotus omarorum, aromatase can modulate non-breeding related aggression in a manner independent from the gonad, and in the face of low plasma hormone levels 31 , which may indicate that genetic modifications to this pathway might be able to influence aggression in both sexes. Signaling peptides also play a role in aggression in cichlids; additional studies using the A. burtoni model found no association of aggression with plasma levels of testosterone or 11-ketotestoterone, but found that a reduction in the regulatory peptide somatostatin increases aggressive acts in males 32,33 .…”

Section: Discussionmentioning

confidence: 99%

Heterospecific aggression differs predominately by species, rather than sex, in Lake Malawi cichlid fish

Moore

Roberts

2019

Preprint

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Because of their striking diversity, Lake Malawi cichlid fish have been well studied for male aggression, particularly among dominant males of closely related sister species within the framework of mate-choice and speciation. However, aggression in females has been largely ignored, and variation in aggressive behaviors between more distantly-related taxa is not well understood despite its potential impact in a complex community structure. To better understand variation in patterns of aggression between species, we presented males and females from five species of Lake Malawi cichlid with a non-predator intruder and recorded all movement and aggressive acts. Additionally, we measured excreted cortisol levels the day after the intruder assay to evaluate one physiological aspect of stress response. We identified species-specific patterns in both specific aggressive acts, and overall level of aggression. Additionally, we found that sexual dimorphism in aggressive acts varies by species and act, where the species with the most aggressive males also has aggressive females. Additionally, cortisol levels vary by taxa, and are associated with restless behavior in the intruder assay, but not levels of aggression. These findings have bearing on understanding sex differences in aggression and their impact on community structure in this important model of rapid evolution.fine-scale variation between sister species within the rock genus Metriaclima [M. aurora, M. lombardoi, M. callainos, and M. pyrsonotos], as well as the more distantly related, sand-dwelling species Aulonocara baenschi. Results Aggression differences by sex and speciesAt the broadest levels, behavioral patterns can be visualized with a time-line representation of the ethogram, or catalog of all the behaviors observed in the assay (figure S1), which allows for a non-quantitative overview of the patterns of behavior displayed by each individual fish. A comparison of mean summary values for each behavior (count or duration) by species, sex, and the species by sex interaction showed differences in the most aggressive behaviors. The aggressive behaviors lunging (F(9,61)=3.71, corrected p=0.0063) and chasing (F(9,61)=2.84, corrected p=0.044) have significant species main effects, as did the attentive fin display behavior (F(9,61)=4.69, corrected p=0.0008). Sex and the interaction term were left in the model despite non-significance because M. lombardoi shows aggressive behaviors in males but not females; while this may be an artifact, the pattern is clear for three behaviors, and thus deemed biologically relevant and may be detectable with a greater sample size (figure 1, top three panels). The quiver display was not significantly different by species in the model (F(9,61)=2.36, corrected p=0.117), but was notably only present in 4 of 8 M. aurora males, and a single M. lombardoi male, and thus the only male exclusive behavior recorded (figure 1, third panel from the top).The most aggressive species, M. aurora, and the least aggressive species, A. baenschi display ma...

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Extra-gonadal steroids modulate non-breeding territorial aggression in weakly electric fish

Cited by 43 publications

References 84 publications

Status-Dependent Vasotocin Modulation of Dominance and Subordination in the Weakly Electric Fish Gymnotus omarorum

Status-Dependent Vasotocin Modulation of Dominance and Subordination in the Weakly Electric Fish Gymnotus omarorum

Seasonal and social factors associated with spacing in a wild territorial electric fish

Heterospecific aggression differs predominately by species, rather than sex, in Lake Malawi cichlid fish

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