Abstract In recent years, the production of economically important crustaceans, and decapods in inland saline areas has increased considerably. The osmoregulatory capacity of these decapods renders them culturable in wide salinity ranges, contributing to a global industry valued at billions of dollars. Therefore, gaining insights into the fundamental mechanisms that drive the adaptive capacity of crustaceans to thrive in diverse salinity ranges is essential. This comprehensive review paper unveils the pivotal adaptations of decapods that allow them to flourish in diverse salinities, ranging from freshwater to saline waters. This article discusses the molecular mechanisms of osmoregulation in decapod crustaceans with more emphasis on Litopenaeus vannammei . Moreover, the importance of maintaining an ideal osmotic balance for efficient digestion and nutrient absorption in L . vannamei is discussed. Furthermore, the effect of salinity on disease resistance in these species is explored, highlighting the need for effective disease management in aquaculture. Overall, this review explores the multifaceted factors influencing decapod crustaceans' adaptation to shifting salinities and also emphasizes the ongoing need for continued research in this domain.