Nursery of young Litopenaeus vannamei post-larvae reared in biofloc- and microalgae-based systems

• Published in: Aquacultural engineering 2017-08, Vol.78, p.140-145
• Main Authors: Schveitzer, Rodrigo, de Lorenzo, Marco Antonio, do Nascimento Vieira, Felipe, Pereira, Scheila Anelise, Mouriño, José Luiz Pedreira, Seiffert, Walter Quadros, Andreatta, Edemar Roberto
• Format: Article
• Language: English
• Subjects: Autotrophic; BFT; Shrimp; Total suspended solids
• ISSN: 0144-8609; 1873-5614
• DOI: 10.1016/j.aquaeng.2017.07.001

•We compared the performance of shrimp PLs (PL6 to PL18) in two nursery systems.•BFT can be as effective as the microalgae-based system for the nursery of PLs.•Water usage was lower in the biofloc tanks than in the microalgae-based system.•PL performance was similar in tanks with TSS values of 500 or 700mgL−1. A 13-day nursery trial was conducted to evaluate the performance of young Litopenaeus vannamei post-larvae (from PL6 to PL18) reared in both biofloc and microalgae-based systems at a stocking density of 67 PLs L−1. The effects of different concentrations of total suspended solids (TSS) on PL performance were also evaluated. One experimental group was reared in a conventional microalgae-based system with daily water exchange and daily addition of microalgae (herein called microalgae treatment). The other two experimental groups were reared using biofloc technology (BFT) with daily dextrose addition and no water exchange, but in the “Biofloc-500” treatment, TSS were maintained at around 500mgL−1, while in the “Biofloc-700” treatment, TSS were maintained at around 700mgL−1. Water quality variables remained within the appropriate range for larval culture. In microalgae treatment, ammonia control was likely associated with its assimilation into microalgae biomass and daily water exchange. In biofloc tanks, however, the addition of dextrose stimulated the production of bacterial biomass from ammonia. This system required only 12.9% of the water used by the microalgae treatment since water was not exchanged during the culture. The nursery of young PLs resulted in similar (P>0.05) performance in all treatments: survival >94%, PL length ∼ 11.5mm, and PL dry weight ∼ 1.2mg. In addition, the salinity stress test (>90.0%) was not significantly different among treatments. Our results indicate that BFT can be as effective as the microalgae-based system for the nursery of young L. vannamei post-larvae. We also found that post-larvae performance was similar (P>0.05) between biofloc treatments, indicating that organisms can tolerate environments with large quantities of solids.