WWW.WAS.ORG • WORLD AQUACULTURE • SEPTEMBER 2017 27 (1.72 ± 0.52 kg) were moved to a recirculating system (Fig. 3) consisting of units for mechanical filtration, biological filtration, temperature control and UV disinfection. After one month of maturation of the recirculating system at ambient conditions (23 C), temperature was increased from 23 to 27 C in four weeks. After five weeks at 27 C, fish were sampled (Fig. 4A) and oocytes (Fig. 4B) were measured following Ibarra-Castro and Alvarez-Lajonchère (2009, 2011b). Both females had eggs with a vitellogenic oocyte diameter of 393 ± 7 µm. Final oocyte maturation was induced using LHRHa in a cholesterol pellet at a dose of 130 mg/kg (Fig. 4C). Males were given a single implant dose of 635 ± 217 µg/kg LHRHa in an EVAc Implant. After hormonal treatment, one female and three males were stocked into each of two 5-m3 fiberglass tanks with continuous strong aeration and ambient seawater (24.8 C and 35 g/L salinity) at a flow rate sufficient to provide an exchange of four tank volumes per day. Fish spawned 62 h after induction (Fig. 4D) and 1.97 million eggs were collected from three spawns. Fertilization was 21 ± 18 percent at 12-14 h after spawning and 95 ± 4 percent of buoyant eggs had live normal embryos. Egg and oil droplet diameters were 696 ± 3 µm and 197 ± 2 µm, respectively. A B FIGURE 5. A) Pacific white snook embryo 12 h after fertilization and B) newly hatched larvae. FIGURE 6. Pacific white snook at first feeding. A B FIGURE 7. A) Weighing Pacific white snook at harvest and B) growth curve of Pacific white snook. FIGURE 8. Larval culture facility in the pilot-scale hatchery at CIAD-Unity Mazatlan, Mexico. (CONTINUED ON PAGE 28)
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