Effects of Biofloc Technology (BFT) on Growth of Speckled Shrimp (Metapenaeus monoceros)

The effects of biofloc technology (BFT) on growth and hepatopancreas histology of speckled shrimp Metapenaeus  monoceros (initial weight: 8.32±0.69 g) were investigated for 30 days. The trial was conducted in fiberglass tanks (45  L) with biofloc (zero-water exchange) and without biofloc (water exchange 50% day-1). Different carbon sources (corn  starch: CS and glycerine: G) and mannan oligosaccharides (MOS) supplementation (with and without BFT) were tested  in triplicate groups. At the end of the experiment, better growth performances, feed conversion ratio, and specific growth  rates were detected in shrimps reared in BFT (CS, G, CS+MOS, G+MOS) groups. Measured water quality parameters  (dissolved oxygen, pH, temperature, salinity, ammonium-NH4, and nitrate-NO3) did not differ between BFT and control  groups. The total number of bacteria count of shrimp reared in the biofloc groups were higher (4.9x10-6±8.5x10-4 CFU  mL-1) than that of in the without biofloc (3.7x10-6±5.4x10-4 CFU mL-1) groups. In this study BFT had no negative effects  on hepatopancreatic tissue by histological assessment. It is suggested that corn starch as a carbon source in BFT with 3  g kg-1 MOS supplementation could be applied as healthy growth enhancer in speckled shrimp culture.