Effect of Stocking Densities on Growth Performance of Mud Crab ( <i>Scylla olivacea</i> ) in the Earthen Pond System in Southwest Region of Bangladesh

ABSTRACT Coastal communities in Bangladesh face significant challenges due to long‐term salinity intrusion, leading to economic vulnerability and environmental stress. The remarkable adaptability of mud crabs to saline environments has encouraged coastal farmers to transition from shrimp aquaculture to mud crab fattening as an adaptive strategy. However, the sustainability of this practice is challenged by the overexploitation of wild seed, elevated mortality rates, suboptimal stocking densities and lack of standardized hatchery‐produced crablets. Therefore, the present study aimed to evaluate the growth performance and survival of juvenile mud crabs ( Scylla olivacea ) reared at three different stocking densities (2, 4 and 6 crab/m 2 ) randomly allocated in triplicate earthen grow‐out ponds over a 90‐day culture period. Hatchery‐reared juvenile mud crabs (1.78 ± 0.18 g) were stocked into 80 m 2 earthen ponds, where Nypa palm ( Nypa fruticans ) leaves were used as shelters covering 30% of the pond area. Survival rate, growth performance and key physicochemical parameters were monitored throughout the culture period. Principal component analysis (PCA) was also done to explain other factors that may influence the growth performance of crabs during culture. Crabs were fed once daily in southwestern areas with experimentally formulated feed with 45% protein. The findings revealed that stocking density significantly affected ( p &lt; 0.05) the survival rate. Crablets stocked at 2 and 4 crab/m 2 had a significantly ( p &lt; 0.05) higher final mean weight than crablets stocked at 6 crab/m 2 . Crabs reared at a moderate stocking density (4 crab/m 2 ) demonstrated higher yields than other treatments. Stocking with 6 crab/m 2 exhibited the higher number of deformed crabs. These results indicate that a stocking density of 4 crab/m 2 is recommended for the grow‐out of S. olivacea crablets in earthen ponds. Optimal stocking density will provide scientific basis to enhance production efficiency, reduce mortality and promote sustainable mud crab aquaculture in Bangladesh.