Aquamimicry improves the growth performance and immunity of black tiger shrimp ( Penaeus monodon ) in low saline ponds

Shrimp farming is currently a great challenge because of unexpected diseases and increasing prices of commercial feed. This study was conducted to evaluate the effects of the aquamimicry culture technique, based on the application of fermented rice bran as a replacement for commercial feed, on the growth, immunity, and survival rate of black tiger shrimp (Penaeus monodon) reared under natural conditions to address these challenges. Aquamimicry culture ponds were designed with high-density polythene liners in the embankment to prevent soil erosion, and a central pit with a suction pump to remove accumulated culture waste, while traditional existing ponds were prepared following standard methods. The liquid fermented rice bran (LFRB) was used to produce food before stocking. Shrimp were grown for 90 days in one of three treatments: T0 (control):100% commercial feed (CF) in a traditional pond, T1:90% CF + 10% LFRB, or T2:70% CF + 30% LFRB in aquamimicry pond with a density of 10 PL/m2. LFRB was prepared by fermenting rice bran with Bacillus subtilis for 24 h under continuous aeration. The average growth rate of shrimp was significantly higher in T2 (0.47 g day- 1) than in T1 (0.34 g day- 1) or T0 (0.05 g day- 1). The survival rate of the shrimp was significantly higher in treatments T2 (55 +/- 12%) and T1 (45 +/- 8%) than in treatment T0. Furthermore, Vibrio parahaemolyticus, the pathogenic strain responsible for early mortality syndrome in P. monodon, was identified based on bacterial colony morphology obtained from the water and hepatopancreas of shrimp in the control ponds. The shrimp in the T2 treatment had a healthier hepatopancreas and significantly higher total hemocyte count (3.6x103cells mL-1) than the shrimp reared in T0 (2.5x103cells mL-1) and T1(2.5x103cells mL-1). This study revealed that the aquamimicry culture technique could ensure better growth, immunity, and survival rates of black tiger shrimp, whereas 70% CF + 30% LFRB (i.e., T2) showed the best performance.