Application of Indoor Recirculation Aquaculture System for White Shrimp (Litopenaeus vannamei) Growout Super-Intensive Culture at Low Salinity Condition

Abstract

The use of close aquaculture system including Recirculation Aquaculture System (RAS) has been implemented to allow a more stable water quality, good hygiene and efficient use of water resources in wide shrimp aquaculture production. This study aims to optimize shrimp stocking density and to evaluate microbial community profile in super-intensive culture of Pacific white shrimp (Litopenaeus vannamei) using RAS technology at low salinity. Before stocking, post larvae shrimp was gradually acclimatized from salinity level of 32 ppt to 5 ppt within 14 days. Different stocking density of 500 PL/m3, 750 PL/m3 and 1,000 PL/m3 were tested in four replicates. During 84 days grow out period, no differences in water quality parameters were observed. At the end of grow out period, significant differences were found in final body weight (14.87 ± 0.24 g, 13.09 ± 0.78 g, 11.32 ± 0.71 g), survival (70 ± 1.42%, 53.67 ± 4.16%, 44 ± 1.35%), specific growth rate (7.12%BW/day, 6.95% BW/day, 6.79% BW/day), and feed conversion ratio (1.32 ± 0.09, 1.45 ± 0.16, 2.05 ± 0.24) for the 500 PL/m3, 750 PL/m3, and 1,000 PL/m3 treatment group, respectively. However, similar total productivity of 5.20 kg/m3, 5.24 kg/m3, and 4.99 kg/m3 was observed for 500 PL/m3, 750 PL/m3, and 1,000 PL/m3 treatment group, respectively. The implementation of RAS can allow a stable community structure of culturable bacteria even at high shrimp density of up to 1,000 PL/m3, with the observed bacterial abundance of 1.28 × 103 to 5.28 × 104 CFU/mL and 9.49 × 104 to 2.27 × 106 CFU/mL in shrimp and culture water, respectively. It is suggested that the application of RAS at the optimal shrimp density of 500 PL/m3 allowed a high shrimp culture productivity of up to 5.20 kg/m3 within 84 days grow out period.