Phenotypic plasticity enables organisms to alter their phenotype in response to environmental changes, enhancing survival and reproductive success. This ability is particularly evident in fish, where it manifests in changes to growth rates, metabolic processes, and behaviors habitat use patterns in response to factors like temperature and food availability. Phenotypic plasticity is observed in fish species using habitats with saline gradients. Adaptive plasticity allows fish to optimize fitness under varying conditions, but rapid or extreme changes can lead to maladaptive outcomes ​. Recent epigenetic research highlights how environmental stressors induce heritable gene expression changes, facilitating rapid evolutionary responses. In the context of climate change, phenotypic plasticity is crucial for fish survival as it enables adaptation to rising temperatures and altered ecosystems​​. Understanding these mechanisms is essential for predicting species responses and developing conservation strategies.