Three treatments were set up using glass aquarium (45 cm 32 cm 32 cm), which were stocked with three prawns. The initial mean weight was 2.2 0.1 g in each aquarium, each one containing 0.04 m3 brackish water (22e28PSU).Salinityiscalculatedasaconductivityratioofthe water sample to a standard KCl solution on Practical Salinity Scale (PSS) and this is referred to PSU (Practical Salinity Unit) inthispaper.Forty-fiveday-oldpostlarvaeofPanaeusmonodon (PL45) werepurchased froma hatchery withan averageweight of about 2.0 g for acclimatization in the aquarium with light intensity of 80 mmol m2 s1, before the outdoor experiment. Two experiments in different combination of shrimp growout period and the initial weight of shrimp were conducted. The first combination (Experiment 1) was of 60 days of growout period and initial weight of shrimp of 2.0 g. The second combination(Experiment 2) wasof 120 daysof growoutperiodand initial weight of shrimp equal to 10.0 g.