Emerging challenges and sustainability pathways in global aquaculture of mud crab (genus Scylla)

Mud crab aquaculture (genus Scylla) has expanded substantially across Southeast Asia in response to increasing market demand and improvements in hatchery and grow-out production systems. Despite this expansion, the sector continues to face environmental, economic, and genetic constraints that affect production stability and long-term sustainability. Existing studies commonly address these issues separately, with limited integration across production stages and management contexts. This review evaluates current knowledge on the major challenges affecting mud crab aquaculture, including habitat degradation, water quality deterioration, disease outbreaks, high production costs, market volatility, labor intensity, and reduced genetic diversity. Evidence across hatchery, nursery, and grow-out systems indicates that environmental stressors influence disease occurrence and survival, while economic pressures limit investment in biosecurity, feed improvement, and technological adoption. In addition, reliance on wild-sourced broodstock and insufficient genetic monitoring may reduce adaptive capacity in cultured stocks. By organizing these findings within a production-stage perspective, this review highlights common constraints, identifies practical management implications, and outlines directions for strengthening coastal governance, broodstock management, and technological adoption. The synthesis aims to support more coordinated approaches to sustainable development in mud crab aquaculture.