WWW.WAS.ORG • WORLD AQUACULTURE • SEPTEMBER 2017 45 The management and protocol of larval and post-larval feeding are summarized in Table 1. At PDFSA, larvae were also grown in static systems in 1000-L fiberglass tanks, with seawater (35 UPS) filtered and sterilized by UV radiation. Photoperiod was controlled with an automatic timer and set to 12 h light and 12 h dark. The management and protocol of larval and post-larval feeding are summarized in Table 2. Juvenile Culture Juveniles were reared in three types of systems: 1) a static system (SS) from 110 to 194 DPH (~ 1 kg/m2), 2) a RAS in the Fish Culture Laboratory of IMARPE (RAS-L) from 103 to 194 DPH (~ 2 kg/ m2) and 3) a RAS at a commercial pilot level in the Culture Center of PDFSA (RAS-C) from 105 to 196 DPH, where juveniles were maintained at a higher density (~ 4 kg/m2). In all systems, water filtered through 1 μm mesh and sterilized by UV radiation was used. At IMARPE, in the SS, juveniles were held in eight fiberglass tanks of 500-L capacity (Fig. 1). A daily water exchange of 80 to 100 percent was applied and biometric samples were collected every fifteen days. In the RAS-L, individuals were kept in two 700-L fiberglass tanks and the components of the system included a biofilter, UV light Broodstock Management The Fish Culture Laboratory of the Alexander von Humboldt Aquaculture Research Center of IMARPE has a stock of P. adspersus breeders in two recirculating aquaculture systems (RAS) (Carrera et al. 2013). Gonadal maturation was induced through application of a regular photoperiod (12 light hours and 12 dark hours) and a temperature of 16.7 ± 0.8 C. For spawning, a mature female was selected with an average oocyte diameter > 500 μm and two males with sperm motility greater than 50 percent. A synthetic analogue of gonadotropin-releasing hormone (buserelin acetate, Conceptase®) was given to the female by intraperitoneal injection at 0.1 mL/kg and, in the case of the two males, 0.1 mL/kg fish by intramuscular injection. Broodstock management and spawning technique carried out at PDFSA was similar to that at IMARPE, also in RAS. Larval Development At IMARPE, larvae were cultured in static systems from 1 day post hatch (DPH) in 150-L fiberglass tanks with seawater (35 UPS) filtered and sterilized by ultraviolet (UV) radiation, with constant aeration and illumination between 905 and 1245 lux. Continuous light was applied for the first ten days of culture and then a photoperiod of 12 h light and 12 h dark was applied until the end of the experiment. (CONTINUED ON PAGE 46) FIGURE 3. Biometric sampling of juvenile Paralichthys adspersus in a recirculating system at the IMARPE laboratory. FIGURE 4. Juvenile culture of Paralichthys adspersus in recirculating system at commercial pilot level at Pacific Deep Frozen S.A. FIGURE 5. Biometric sampling of Paralichthys adspersus in a recirculating aquaculture system at commercial pilot level at Pacific Deep Frozen S.A.
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