Alondra I. Ortiz Franco¹, Oscar Hernandez-Acevedo,¹,, Alana Lopez-Cruz¹, Fabiola Pagan-Torres¹, Andrea Semidei-Rodriguez¹, Alejandro Dueño-Sosa¹, Roberto Rodriguez-Morales¹

 Institutions: (1) Department of Anatomy and Neurobiology, UPR-Medical Sciences Campus, San Juan, PR

Aggression is a highly conserved social behavior within the animal kingdom. Previous work from vertebrate and invertebrate models suggests that evolution of aggression is complex, with a genetic basis while also affected by environmental factors. Further, aggressiveness can vary within individuals of the same species, and the mechanisms underlying these variations are largely unknown. We hypothesize that previous social experiences can influence the display of future aggressive interactions in an individual, and that these will vary depending on previous exposure to highly aggressive or non-aggressive individuals. To test this, we turn to the Mexican tetra, Astyanax mexicanus, a single species composed of two morphotypes: highly aggressive river-dwelling surface fish with eyes, and non-aggressive cave-dwelling cavefish with no eyes. Using a resident/intruder assay, we will expose pairs of highly aggressive surface fish in a resident/intruder contest repeatedly to create asymmetric social structures between both individuals (the “winner” and “loser” effect). Next, we will expose both winner and loser surface fish to docile Pachón cavefish, to answer whether previous experience determines their social interaction with a novel-nonaggressive conspecific. Preliminary data suggests that when submissive fish are exposed to nonaggressive fish these tend to be aggressive regardless of their previous role. Also when faced back to their original opponent they will submit and revert back to their submissive role. Taken together, these results suggest that we can establish that a repeated social defeat can cause the individual to remember their role when faced to the same opponent. Due to imprinting of this experience, this individual may turn aggressive. These findings may have broader implications for unraveling the dynamics of social behavior, potentially contributing to the development of public health strategies for mitigating aggression in animal populations.