By B. Chuntapa, S. Piyatiratitivorakul, C. Nitithamyong, V. Viyakarn and P. Menasveta - This study aimed at determining the optimal lipid:carbohydrate and protein:energy ratios for growth and survival of juvenile Penaeus monodon Fabricius. Two experiments were performed using completely randomized designs in semi-closed recirculating water systems.