Aquaculture Nutrition. 2018;1–8. wileyonlinelibrary.com/journal/anu | 1 © 2018 John Wiley & Sons Ltd 1 | INTRODUCTION The intensification of production in shrimp culture demands that at- tention be given to the reared organisms’ welfare, integrated water management systems that avoid or minimize the pollution of water bodies (i.e., release of nitrogenous compounds) and greater controls over potential infections by pathogens (Xie & Yu, 2007; Moss, Moss, Arce, Lightner, & Lotz, 2012; Xu & Pan, 2013). All of these actions are particularly important for rearing the Pacific white shrimp Litopenaeus vannamei, one of the most marketed aquatic organisms worldwide (Xu & Pan, 2013). Biofloc technology systems (BFTs) provide a sustainable solution that improves water quality while removing toxic nitrogen (ammo- nia, nitrite), and they also provide the highest growth performance through the feed supplements and digestive stimulants from biofloc organisms (Xu & Pan, 2013). BFTs are rich in natural microorganisms Received: 18 January 2017 | Accepted: 16 December 2017 DOI: 10.1111/anu.12663 ORIGINAL ARTICLE Antioxidant effects of nanoencapsulated lipoic acid in tissues and on the immune condition in haemolymph of Pacific white shrimp Litopenaeus vannamei (Boone, 1931) Á.C. da Silva Martins 1,2 | J. Artigas Flores 1 | C. Porto 1 | L.A. Romano 1,2,3 | W. Wasielesky Junior 1,2,3 | S.S. Caldas 1,4 | E.G. Primel 1,4 | I. Külkamp-Guerreiro 5 | J.M. Monserrat 1,2,6,7 1 Universidade Federal do Rio Grande—FURG, Rio Grande, Brazil 2 Programa de Pós-graduação em Aquicultura, FURG, Rio Grande, Brazil 3 Instituto de Oceanografia (IO), FURG, Rio Grande, Brazil 4 Escola de Química e Alimentos (EQA), FURG, Rio Grande, Brazil 5 Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, Brazil 6 Instituto de Ciências Biológicas (ICB), FURG, Rio Grande, Brazil 7 Laboratório de Bioquímica Funcional de Organismos Aquáticos (BIFOA), Centro de Biotecnologica e Doenças de Organismos Aquáticos (CBD), IO, FURG, Rio Grande, Brazil Correspondence José Maria Monserrat, Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande—FURG, Rio Grande (RS), Brazil. Email: monserrat_jm@furg.br Funding information Conselho Nacional de Desenvolvimento Científico e Tecnológico, Grant/Award Number: DT 311694/2016-0, PQ 307880/2013-3 and PQ 310993/2013-0; MCTI/CNPq/FNDCT, Grant/Award Number: 408921/2013-7 Abstract The antioxidant and oxidative damage responses and immune parameters in shrimp, Litopenaeus vannamei, reared in clear water (CW) and in a biofloc system (BFT) were evaluated. The animals were given feed supplemented with either nanocapsules con- taining the antioxidant lipoic acid (NCLA) or empty nanocapsules (NC). Antioxidant and oxidative stress analyses were evaluated by measuring glutathione S-transferase activity (GST), reduced glutathione (GSH) concentration and lipid peroxidation (TBARS) in the gills, hepatopancreas and muscle. The immune parameters were then deter- mined by the differential hemocyte count in the haemolymph. The final weight of the shrimp reared in both CW and BFT and treated with NCLA increased (p < .05). The shrimps reared in BFT showed increased GST activity in the gills and hepatopancreas after NCLA treatment (p < .05). Higher GSH levels were observed in the hepatopan- creas with NCLA supplementation in CW and BFT (p < .05). Decreased levels of TBARS were observed in the gills and muscles of shrimp supplemented with NCLA and maintained in CW (p < .05). A decrease in the percentage of hyaline hemocytes and an increase in granular hemocytes were observed in shrimp treated with NCLA in CW and BFT (p < .05). The antioxidant treatment induced positive responses in terms of the zootechnical, biochemical and immunological parameters. KEYWORDS antioxidant defences, antioxidants supplements, biofloc system, nanotechnology, oxidative damage, shrimp