A sexual dimorphism in zebrafish aggression and metabolism under acute ammonia stress.

Animals must adapt their behaviors in response to environmental stressors to enhance survival prospects. Aquatic organisms, particularly teleost fish, face unique environmental challenges, making them ideal models for studying environmental stress adaptation. While previous research on acute environmental stress acclimation provided valuable insights, it often overlooked potential sex-specific responses. Growing evidence suggests significant sexual dimorphism in physiological and behavioral responses to various environmental stressors. This emerging paradigm reveals a critical knowledge gap in our understanding of sex-specific stress acclimation strategies and their underlying mechanisms in teleost fish. To address this gap, we investigated the effects of acute ammonia exposure, a common aquatic stressor, on male and female zebrafish. We examined differential behaviors and metabolic rates between the sexes under ammonia stress and found sex-specific responses: males tended to recover aggression and reduce fighting latency without affecting outcomes, whereas females exhibited lowered oxygen consumption and reduced aggression. These findings highlight differences in acute stress adaptation strategies between males and females, contributing to a more-comprehensive understanding of sex-specific stress adaptation in aquatic environments and underscoring the importance of considering sexual dimorphism in environmental stress studies.