The increasing demand for aquaculture production under limited land availability requires efficient intensive culture systems. This commercial case study evaluated the production performance and economic viability of whiteleg shrimp, Penaeus vannamei Boone, 1931, cultured in an HDPE-lined circular tank system under commercial farm conditions across three sequential production cycles with progressively increasing stocking densities (318-467 ind m⁻²). Progressive intensification was associated with higher biomass production, increasing total biomass from 1,500 to 2,015 kg and yield from 4.78 to 6.42 kg m⁻². However, this was accompanied by a decline in survival (94-80%) and a slight increase in feed conversion ratio (FCR) (1.20-1.29), indicating trade-offs between production and biological performance. Most water quality parameters remained within acceptable ranges throughout the culture period, although total ammonia nitrogen (TAN) increased across successive production cycles as stocking density increased. Despite higher production costs, economic performance improved, with net profit increasing from USD 2,852.80 to USD 4,730.17 and return on investment (ROI) from 58.78% to 66.61%. Annual production reached 5,300 kg, with an overall ROI of 63.63% and a benefit-cost ratio of 1.64. These findings suggest that HDPE-lined circular tank systems can support profitable intensive shrimp production under space-limited conditions when supported by appropriate feeding, aeration, and water quality management. Because the study was conducted in a single commercial production system using sequential, non-replicated production cycles, the findings should be interpreted as operational observations rather than definitive evidence of stocking density effects. Further replicated studies are needed to determine the optimum stocking density for maximizing productivity, economic returns, and biological performance.
