Current Challenges and Issues in the Application of Astaxanthin

Astaxanthin, a xanthophyll carotenoid, exhibits potent biological functions, including antioxidant, immune regulation, growth promotion, improved reproductive capacity, and enhancement of the body color of aquatic animals. In recent years, with the rapid development of the aquaculture industry, the application of astaxanthin in aquaculture has garnered increasing attention. Studies have demonstrated that astaxanthin significantly enhances the antioxidant capacity of aquatic animals, reduces oxidative damage, and regulates the expression of immune-related genes, thereby improving immunity and disease resistance. Moreover, astaxanthin promotes growth and reproductive performance, particularly in high-value aquaculture species, where it also serves as a natural pigment to increase market competitiveness. However, the low bioavailability and high production costs of astaxanthin remain major constraints to its widespread use in aquaculture. To address these limitations, various strategies—such as microencapsulation, liposomal delivery, and nanotechnology—have been explored to improve its stability and water solubility. Additionally, expanding astaxanthin sources and optimizing production processes are effective approaches to reducing costs. This review summarizes recent advances in astaxanthin research within aquaculture, highlights its multifunctional roles in promoting the health and production efficiency of aquatic animals, and discusses the current challenges and future research directions.