Cellular mechanisms in aquatic animals govern their responses to environmental stress, disease, and growth. These processes, such as immune responses, metabolism, and osmoregulation, are critical for survival in diverse aquatic ecosystems. Understanding cellular signaling pathways helps in improving aquaculture practices by identifying key genes that regulate disease resistance, growth, and adaptation. Advances in genomics and molecular biology have allowed aquaculturists to pinpoint genes involved in stress tolerance and metabolic efficiency. This knowledge is key to developing resilient species, enhancing aquaculture performance, and managing health challenges in farmed aquatic animals, leading to more sustainable operations.