Effects of different carbon sources on growth performance of Litopenaeus vannamei and water quality in the biofloc system in low salinity

Abstract

This study aimed to investigate the effects of different carbon sources on water quality and growth performance of Litopenaeus vannamei in the biofloc system under a salinity condition as low as 5‰. Three biofloc treatments with glucose (Glu), molasses (Mol) and starch (Sta) as carbon source, respectively, were designed to stocking shrimp juveniles (0.81 ± 0.02 g) at a density of 90 individuals m−3 for a 63-days culture experiment. Results showed that there was no significant difference on shrimp performance and water quality between Glu treatment and Mol treatment. The final mean body weight, weekly increment rate of body weight, specific growth rate, feed efficiency rate, productivity and survival rate of shrimp in Glu and Mol treatments, were all significantly higher than those in Sta treatment (P < 0.05). Significantly higher pH and carbonate alkalinity (P < 0.05), but significantly lower levels of total ammonia nitrogen, nitrite and nitrate (P < 0.05), were also found in Glu and Mol treatments, when compared to those in Sta treatment. The results indicated that in the biofloc system with a low salinity in the present study, soluble glucose and molasses are good carbon sources for grow-out culture of L. vannamei shrimp.