Farming of shrimp Litopenaeus schmitti with different salinities and dietary protein levels in bioflocs system

Abstract

The objective of this study was to investigate the effect of protein levels in the diet on the water quality, bioflocs composition and shrimp development of Litopenaeus schmitti reared in different salinities using bioflocs technology (BFT). Juveniles L. schmitii (2.43 ± 0.35 g) were kept in tanks with 400 L (40 shrimps m^-²) in three salinities (19, 26 and 33) and fed two commercial diets (30 and 40% crude protein) during a period of 35 days. Among the water quality parameters monitored, concentrations of nitrite were affected by the interaction of factors, as protein levels in the diet and salinity and by salinity alone (P<0.05). The shrimps development was affected by factors, such as salinity and protein level of the diet alone (P<0.05). As for dietary protein, the protein efficiency indicated that shrimps used better this nutrient, when they were fed the diet containing 30% protein content (2.23 ± 0.31) compared to 40% (1.87 ± 0.16) (P<0.05). With respect to salinity, the survival of shrimps presented higher value in the superior salinity (P<0.05). Therefore, results showed that the microbiological composition of bioflocs was affected by the factors evaluated, and that the farming of shrimp L. schmitti with the bioflocs technology, in any one of salinities used, can be performed with supply the diet with the lowest tested level of protein to obtain better productive performance of the species.