Comparative analysis of morphological characteristics and nutritional quality in wild-caught and pond-reared female mud crab, Scylla paramamosain

Abstract

The mud crab Scylla paramamosain is an important species in marine aquaculture, valued for its high commercial price and consumer demand. Wild-caught individuals are often perceived as superior in taste and texture and thus command premium prices, while pond-reared crabs are more accessible and produced under controlled conditions. However, the nutritional quality differences between wild-caught and pond-reared individuals remain unclear, which poses challenges for market differentiation, consumer guidance, and aquaculture optimization. This study investigated the differences in nutritional quality between wild-caught and pond-reared female S. paramamosain, and further conducted morphometric analyses to determine whether they can be reliably distinguished. Morphometric analyses indicated significant differences in 12 of 18 measured parameters, with wild-caught crabs exhibiting relatively longer pereopods and swimming legs. Proximate composition analyses revealed minimal differences, except that pond-reared crabs had a significantly higher hepatosomatic index (HSI), while wild crabs exhibited higher muscle ash content. Pond-reared crabs possessed higher yellowness (b*) in carapace and ovary, higher redness (a*) and yellowness (b*) in hepatopancreas and muscle, and elevated total carotenoid levels across tissues. Fatty acid analyses indicated higher EPA but lower DHA levels in wild-caught crab ovaries and hepatopancreas, resulting in a significantly increased EPA/DHA ratio. Amino acid profiles showed no significant difference in total essential amino acids in ovaries and muscle between groups, with essential amino acid scores (EAAS) all exceeding 100. Overall, results suggest that pond-reared female S. paramamosain has higher dietary nutritional value and can be distinguished from wild-caught counterparts using morphometric analysis. These findings have practical implications for market differentiation and consumer guidance, supporting value-based pricing and informed dietary choices in the seafood industry.