Effect of different levels of biofloc on water quality, growth performance and survival of Litopenaeus vannamei post larvae

In recent years, the use of biofloc has been considerable as a culture method to protect water quality and reduce the cost of food in the environment cultured shrimp. The purpose of this study was to evaluate the effects of different levels of biofloc on water quality, growth performance and survival of Litopenaeus vannamei post larvae reared with no water exchange. Post larvae with weight of 7.48 ± 0.85 mg and length of 9.23 ± 0.49 mm were reared in fifteen tanks with volume of 40-L and stocking density of 10 PL/L. Different levels of biofloc were added to tanks’ water as food sources: B0 (100% concentrate); B75 (75% biofloc +25% concentrate); B50 (50% biofloc +50% concentrate); B25 (25% biofloc +75% concentrate) and B100 (100% biofloc). The experiment was carried out for twenty=eight days. Total ammonia nitrogen (TAN) level was lower in B25 than other treatments (P<0.05). The levels of Nitrate (mg NO3–N L−1) were significantly lower in B25 and B50 in 28 days of the experiment than in other treatments (P<0.05). At the end of the experiment, results showed that shrimp growth and survival were higher in B25 (301.23± 32.20 g and 81.56%, respectively) than in other treatments (P<0.05). The concentration of TSS tended to increase in the treatments during the experiment. The results from this study suggest that replacement of 25% biofloc (B25) with food concentrate can improve growth performance and water quality of the cultured shrimp.