Mud Crab Aquaculture: Biological Foundations, Production Bottlenecks and Sustainability Pathways in Scylla Farming

Abstract

Mud crabs of the genus Scylla support high-value fisheries and aquaculture across the tropical Indo-Pacific, yet the sector remains technologically uneven and closely coupled to wild resources. This critical narrative review evaluates the biological and production evidence underpinning Scylla aquaculture, with emphasis on species identity, broodstock and hatchery management, larviculture, nursery and grow-out systems, nutrition, environmental physiology, health and biosecurity, domestication, genetics, economics, and sustainability. Literature published from 1998 to 5 August 2026 was identified through agriculture, biomedical, multidisciplinary, and open scholarly indexes, supplemented by citation searching and authoritative institutional sources. Evidence was appraised for species verification, life stage, experimental design, replication, husbandry control, outcome validity, field relevance, and transferability. The literature shows that the principal constraint is not a single husbandry variable but a weakly integrated production chain. Hatchery survival remains inconsistent; nurseries are constrained by cannibalism and size heterogeneity; grow-out performance depends strongly on stocking design, shelter, feed quality, environmental stability, and disease control; and many farming systems still depend on wild broodstock, crablets, or subadult crabs. Species-level differences further limit the validity of transferring results among S. serrata, S. olivacea, S. paramamosain, and S. tranquebarica. Nutrition research demonstrates clear stage- and species-specific responses, but commercially validated formulated feeds remain limited. Disease reports increasingly implicate viral, bacterial, parasitic, and shell-associated syndromes, reinforcing the need for preventive biosecurity rather than reactive treatment. Domestication and genomic tools are advancing, particularly for S. paramamosain and S. serrata, but multi-generation selection, genetic management, welfare assessment, and independent economic validation remain sparse. The strongest pathway towards sustainable expansion is therefore an integrated one: species-verified captive seed production, standardised hatchery and nursery protocols, nutritionally adequate feeds, risk-based biosecurity, genetic stewardship, and explicit accounting for wild-seed dependence, mangrove interactions, labour, market risk, and animal welfare.