Organic, inorganic and nanoparticles of Se, Zn and Mn in early weaning diets for gilthead seabream (Sparus aurata; Linnaeus, 1758) Marisol S Izquierdo 1 , Wafa Ghrab 1 , Javier Roo 1 , Kristin Hamre 2 , Carmen M Hern andez-Cruz 1 , Giovanni Bernardini 3 , Genciana Terova 3 & Reda Saleh 1,4 1 Grupo de Investigaci on en Acuicultura (GIA), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain 2 National Institute of Nutrition and Seafood Research (NIFES), Bergen, Norway 3 University of Insubria, Varese, Italy 4 Oceanography Department, Faculty of Science, Alexandria University, Alexandria, Egypt Correspondence: M Izquierdo, Grupo de Investigaci on en Acuicultura (GIA), Universidad de Las Palmas de Gran Canaria, Trans- monta~ na s/n, 35416 Arucas, Las Palmas de Gran Canaria, Spain. E-mail: reda-saleh@hotmail.com Abstract Levels of the oxidative stress-related minerals sele- nium (Se), zinc (Zn) and manganese (Mn) that should be supplied in microdiets for marine fish larvae depend on the availability of the molecular form of these minerals. The objective of this study was to determine how effectively Se, Zn and Mn in organic, inorganic and nanoparticle forms promote larval performance and bone development. Microdiets supplemented with Se, Zn and Mn were fed for 24 days to 20 dah seabream larvae. Microdiets without Se, Zn and Mn supplementa- tion were associated with poor growth, low bone mineralization and a high incidence of anomalies in the branchial arches. Including Zn, Mn and Se in an amino acid chelate organic form promoted maximum larval growth, increased body lipid reserves, enhanced early mineralization and pre- vented branchial arches anomalies. In contrast, feeding with inorganic forms of these minerals was less effective than organic minerals in improving larval weight or bone mineralization in compar- ison to the non-supplemented diet. Moreover, the larvae were less resistant to stress, and fish showed higher bone anomalies in the pre-hemal region. Adding Zn, Mn and Se in the form of nanometals did not enhance growth, but improved stress resistance and bone mineralization. The study showed the need to supplement seabream with early weaning diets based on squid meal and krill oil with one or more of the antioxidant miner- als, to promote larval growth, bone mineralization and prevention of skeleton anomalies, organic minerals being more effective than inorganic forms and nanometals in promoting mineralization and stress resistance. Keywords: larval nutrition, selenium, man- ganese, zinc, skeletal anomalies, bone mineraliza- tion Introduction Despite the important roles of minerals for organ functioning and development, information about mineral nutrition in marine fish larvae is very scarce. Mineral content in copepods, natural live prey for these larvae, can vary greatly from species to species (Fujita 1972; Watanabe, Arakawa, Kita- jima, Fukusho & Fujita 1978) and is probably affected by the abundance and variety of microal- gae that they ingest. For instance, in copepods the selenium (Se), zinc (Zn) and manganese (Mn) levels are in the range of 3–5, 110–700 and 8– 25 mg kg 1 respectively (Fujita 1972; Watanabe et al. 1978; Hamre, Mollan, Saele & Erstad 2008). Unfortunately, mineral content in hatchery live prey greatly differs from that in copepods, being in rotifers 0–20 mg kg 1 Se, 75–600 mg kg 1 Zn, and 6–11 Mn mg kg 1 (Hamre, Y ufera, Rønnes- tad, Boglione, Conceic ß~ ao & Izquierdo 2013; © 2016 John Wiley & Sons Ltd 1 Aquaculture Research, 2016, 1–16 doi: 10.1111/are.13119