Social Modulation of Intersexual Aggression in Cichlasoma dimerus

Aggressive behavior plays a key role in territory establishment and social organization across vertebrates. Cichlasoma dimerus is a Neotropical cichlid with a marked social hierarchy, in which dominant individuals display aggressive behaviors toward subordinates. While intrasexual agonistic interactions have been extensively described, intersexual aggression remains poorly characterized. Here, we characterized sex differences during intersexual agonistic encounters between dominant males and females. Dyadic encounters lasted 1h, during which aggressive and submissive behaviors were quantified. Males displayed higher aggression (p = 0.02) and won all encounters, whereas females exhibited more submissive behaviors (p = 0.03). We further investigate whether these interactions are modulated by an audience. As a first step, to test whether virtual stimuli can function as social audiences, we quantified the number of aggressive displays and preference index. Focal individuals were exposed to social and non-social visual stimuli, displaying distinct behavioral responses and characteristic social behaviors toward social and aggressive stimuli. This supports the use of virtual audiences to investigate how social exposure modulates intersexual aggression. We are now comparing behavioral responses and brain activation following dyadic intersexual encounters performed with or without an audience, providing insight into the neural mechanisms underlying the social modulation of aggression.