30 SEPTEMBER 2014 • WORLD AQUACULTURE • WWW.WAS.ORG or to the zero-discharge facility at Mote. Following quarantine, weight and length of each fish was measured, sex was determined and fish were implanted with a passive integrated transponder (PIT) tag for identification. Broodstock System Design and Fish Management Black snook were added to a broodstock system that had been used previously to mature and spawn captive common snook (Fig. 4). The 48-m³ system is 6.1 m in diameter by 1.83 m deep and water depth is maintained at 1.52 m. To maintain water clarity and chemistry, each tank is equipped with a 0.085-m³ drop filter (Aquaculture Systems Technologies, LLC, New Orleans, LA, USA) for solids removal, a 900-L moving bed reactor containing 0.283m³ plastic extruded floating media (AMBTM media, EEC, Blue Bell, PA, USA) for biofiltration, a protein skimmer, two 150-W High Output SMART HO UV® units (Emperor Aquatics, Inc®, Pottstown, PA), and 126,000-BTU heater/chiller unit (AquaCal AutoPilot, Inc., St Petersburg, FL, USA). Photoperiod was maintained by four 10,000oK daylight Coralife® bulbs, each on a timer, providing a gradual sunrise and sunset. Water quality and chemistry were closely monitored to ensure proper conditions for fish. Water quality was measured daily with a YSI Pro Plus meter (YSI Inc., Yellow Springs, OH) and were maintained within the following limits: dissolved oxygen concentration ≥5 and ≤ 9 mg/L, temperature ±1 C of the desired temperature, salinity 35 ± 1 ppt, and pH ≥7.5 and ≤8.4. Water chemistry was assessed once weekly and maintained within the following limits: total ammonia nitrogen <0.5 mg/L, total nitrite-N <1.0 mg/L, and total nitrate-N <50 mg/L. If the concentration of any water chemistry parameter was outside these limits, water was exchanged to alleviate the problem. Black snook were initially fed fresh frozen shrimp for three days after being added to the tank. Once fish started eating shrimp, Atlantic thread herring Opisthonema oglinum was added to the the Tranquility Management, R.L. site, maintained in recirculating systems with 8.9-m³ tanks at a salinity of approximately 32 ppt and allowed to recover from collection for a minimum of two weeks before shipping. While held, fish were fed approximately 100 live shrimp per day until five days before shipping. The current population of 7 females and 6 males were transported in two shipments. On the shipping date, snook were removed from the acclimation system, placed in a hauling tote and trucked to San Jose, Costa Rica. Upon arrival, each fish was individually packed in a bag with 90 L of oxygenated water, ClorAm-X (3 g) and the head space of the bag filled with pure oxygen before sealing (Fig. 3). The primary (inner) bag containing the fish was then placed in a protective bag liner (boot), which was placed inside an additional outer bag filled with pure oxygen to provide additional integrity in case of punctures. Bags were placed in styrofoam-lined boxes (1.2 m long × 1 m wide × 0.9 m high) with ice packs. Boxes were secured with plastic shrink-wrap, palletized (two boxes per pallet) and shipped as air cargo on a direct flight to Miami International Airport. Upon arrival in Miami and clearance through customs, bags were opened and dissolved oxygen concentration, pH, salinity and temperature were measured. If the fish in each bag appeared healthy, bags were not punctured. If water quality parameters were within range, the inner and outer bags were refilled with pure oxygen and resealed. Any fish that appeared to be in distress or had lost equilibrium was transferred from the bag into a holding tank to which pure oxygen was supplied through diffusers. Once fish arrived at Mote, water quality was assessed again and water was added to the holding container from the broodstock tank system until water quality was appropriate for fish transfer. Fish were acclimated and treated with copper sulfate pentahydrate (0.2 ppm) for five weeks to prevent introduction of parasites and pathogens to existing broodstock populations TOP, FIGURE 4. Black snook broodstock tank layout at Mote. BOTTOM, FIGURE 5. Representation of the photo-thermal cycle used to induce maturation of black snook broodstock. Arrows indicate sampling events when mature females were observed and implanted with GnRH.
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