Larval development and salinity tolerance of Japanese flounder (Paralichthys olivaceus) from hatching to juvenile settlement Youji Wang 1,† , Qindan Guo 1,† , Hu Zhao 1 , Haijin Liu 2 & Weiqun Lu 1 1 College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China 2 Research Centre for Fisheries Recourse and Environment, Chinese Academy of Fishery Sciences, Beijing, China Correspondence: W Lu, College of Fisheries and Life Science, Shanghai Ocean University, 999 Huchenghuan Road, Shanghai 201306, China. E-mail: wqlv@shou.edu.cn † These authors contributed equally to this work. Abstract Salinity tolerance and growth of Japanese flounder Paralichthys olivaceus at different developmental stages were evaluated, including newly hatched lar- vae (nhl), yolk sac larvae (ysl), oil droplet larvae (odl), post oil droplet larvae (podl), premetamorphic larvae (preml) and prometamorphic larvae (proml), at 11 salinities from 5 to 55 g L À1 for 96 h. The ontogenesis during the early life of P. olivaceus was investigated under hatchery salinity 35 g L À1 . The results showed that suitable salinities for nhl, ysl, odl, podl, preml and proml larvae were 10 to 25 g L À1 , 10 to 30 g L À1 , 20 to 30 g L À1 , 30 g L À1 , 10 to 30 g L À1 , 15 g L À1 , respectively, demonstrating an ontogenetic variation of salinity tolerance. The salinity tolerance of nhl, ysl, preml was higher than that of odl, podl and proml. The ysl and preml larvae displayed wide salinity toler- ances. The present findings demonstrate that the suitable salinity for larviculture of P. olivaceus is 20–25 g L À1 before the depletion of oil droplet; after that, higher salinity (30 g L À1 ) should be ensured for the post-oil droplet larvae; the premetamorphic larvae can be cultured at a wide salinity range (10–30 g L À1 ), and the metamorphosed larvae should be reared at salinity about 15 g L À1 . Keywords: Paralichthys olivaceus, larval develop- ment, salinity tolerance, growth, survival Introduction Salinity is one of the most important abiotic factors which can affect the survival and distribution of fish in coastal and estuarine waters. The effects of salinity variation are important considerations during early life stage of fish (Schreiber 2001). Salinity can strongly influence physiological pro- cesses and morphological developments of larval fish, and has a direct effect on growth and survival by expending the amount of energy needed for osmoregulation (Boeuf & Payan 2001; Varsamos, Nebel & Charmantier 2005). Salinity also affects egg hatching (Mart  ınez-Palaciosa, Morteb, Tello- Ballinasa, Toledo-Cuevasa & Rossb 2004; Yang & Chen 2006; Zhang, Shi, Zhu, Liu & Zang 2010), yolk consumption efficiency (Swanson 1996), larval growth and survival (Murashige, Bass, Wallace, Molnar, Eastham, Sato, Tamaru & Lee 1991; Tandler, Anav & Choshniak 1995; Estudillo, Duray, Marasigan & Emata 2000; Madrones-Ladja 2002; Sampaio & Bianchini 2002; Fielder, Bardsley, Allan & Pankhurst 2005; Sampaio, Freitas, Okamoto, Louzada, Rodrigues & Robaldo 2007). The successful establishment of a species in a given habitat depends on the ability of each devel- opmental stage to cope with changes in salinity through osmoregulation (Varsamos et al. 2005). Because osmoregulation is an energy demanding process, in some fish species, energetic budget is thought to be lower at iso-osmotic salinities (Holli- day 1969), and more energy is available for growth and/or survival (Sampaio & Bianchini 2002). Some marine teleost larvae are able to osmoregulate (Hiroi, Kaneko, Seikai & Tanaka 1998; Miyazaki, Kaneko, Hasegawa & Hirano 1998; Hiroi, Kaneko & Tanaka 1999) and hold their body-fluid ion concentrations at levels © 2013 John Wiley & Sons Ltd 1 Aquaculture Research, 2013, 1–13 doi: 10.1111/are.12343