World Aquaculture Magazine - June 2021

WWW.WA S .ORG • WORLD AQUACULTURE • JUNE 2021 55 maintained for tilapia broodstock (Figs. 3 and 4). Three spawning systems were evaluated: hapa net cage, raceway and arena (Figs. 5-7). The raceway and arena had superior fry production than the hapa net cage because the hapa net cage needs greater management skills and costs more than other systems. We collected fertilized eggs every 15 days and recovered fry every 21 days. A female broodfish can spawn 120 to 550 eggs each period. The hatching rate is more than 95 percent. After generating eggs and fry for 30 to 45 days, we separate female and male broodstock for recovery with supporting nutrition. Larviculture The fry of Sabaki tilapia are strongly cannibalistic. Therefore, after 14 days of fry collection, grading is necessary. To save management costs and growth performance, outdoor farming is a better choice for larviculture. Thus, the protection to avoid bird predators is essential (Fig. 8). Once fry are >1 g (Fig. 9), they are transferred to grow-out ponds. LEFT: FIGURE 5. Outdoor raceway ponds for broodstock spawning. RIGHT: FIGURE 6. Hapas for broodstock spawning. ( C O N T I N U E D O N P A G E 5 6 ) Furthermore, among the various tilapia species, Sabaki tilapia is one of the distinct species in the global tilapia aquaculture industry. Why is the Sabaki tilapia unique? First, Sabaki tilapia can be farmed in a high salinity and high temperature environment because the average salinity in Saudi marine fish farms is over 42‰ and we do not need to worry about acclimatization. For common marine tilapia species such as the Mozambique tilapia Oreochromis mossambicus , product value (size, shape, and processable) is smaller than Sabaki tilapia. Finally, Sabaki tilapia is not yet a popular commercially farmed species. We have an opportunity to be a pioneer. HowDoWeManage the Operations of Sabaki Tilapia? BroodstockManagement Qualified broodstock should be healthy, active and disease free and with a body weight >200 g (Fig. 2). We have collected eligible broodstock of <7 months of age. A sex ratio of 3 females: 1 male was FIGURE 3. Female Sabaki tilapia broodfish. FIGURE 4. Male Sabaki tilapia broodfish.