Use of different carbon sources for the biofloc system adopted during the nursery and grow-out culture of Litopenaeus vannamei

The carbon sources such as molasses cane sugar, dextrose and rice bran were tested in growing Pacific white shrimp, Litopenaeus vannamei, using the Biofloc Technology System, and the reduction in the concentration of total ammonia nitrogen in the experimental nursery and grow-out phases were assessed in tanks with a volume of 800 L at 35 and 70 days, respectively. In the nursery experiment, postlarvae with an average weight of 0.024 +/- A 0.01 g were stocked at 1200 m(-2) and shrimp with an average weight of 4.09 +/- A 0.51 g and stocking density of 300 m(-2) was used in the grow-out. The carbon sources used in the nursery were molasses (M) and rice bran (R) and in the grow-out were dextrose (D) and rice bran (R). In the nursery experiment, using molasses, the ammonia concentration was significantly lower (p < 0.05). In the grow-out experiment with dextrose, the ammonia concentration was significantly lower (p < 0.05), but performance data were significantly better (p < 0.05) in the rice bran treatment. The faster degradation of dextrose and molasses sources may have provided higher levels of carbon as a substrate for heterotrophic bacteria to use in metabolizing ammonia, thereby improving the water quality.