Comparison of growth and survival rates of juvenile mud crab Scylla serrata (Forskal, 1775) fed with trash fish and pelleted feed in pen culture at a tidal pond, Chowfaldandi, Cox's Bazar

The study investigated the effects of two feeding regimes (trash fish vs. commercial pelleted feed) on the growth performance and survival of juvenile mud crab Scylla serrata in pen culture. Four square bamboo pens (1 m × 1 m × 2 m) were used in a tidal pond at Chowfaldandi, Cox’s Bazar, in a 30-day trial (15 February-15 March 2020). Treatments A and D were fed trash fish, andtreatments B and C were fed commercial De Heus floating pellet feed. Juveniles (initial weight range 3-17 g) were stocked at densities of 5 or 8 crabs per m² and fed at 5-10% of body weight every other day. Growth was measured weekly on individually tracked crabs and expressed as average weight gain, specific growth rate (SGR), and production per pen. Water quality remained within acceptable ranges for S. serrata (temperature: 24–29°C; salinity: 30–33 ppt; DO: 7.98–8.65 mg L⁻¹). Results indicated that pellet-fed crabs (especially treatment C) exhibited significantly higher growth (mean daily growth up to 0.488 g day⁻¹, SGR up to 1.131% day⁻¹)and superior feed conversion efficiency (FCR as low as 1.06) compared with trash-fish-fed crabs (FCR up to 4.305). Survival varied among treatments (40–75%), and production was highest in pellet-fed treatment C (total biomass 852.90 g). These findings suggest that commercial pelleted feed can enhance short-term growth and feed utilization in juvenile S. serrata pen culture. Longer-term trials with larger replication are recommended to confirm these results and to assess meat quality and economic feasibility. This study provides baseline evidence supporting the use of formulated feeds to improve productivity in Bangladesh’s emerging crab aquaculture sector.