WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2025 31 Asian seabass (Lates calcarifer), also known as barramundi, is an important finfish species in global aquaculture, ranking 35th among discrete fish species and 42nd across all FAOidentified fish categories. Global production reached 154,281 tonnes in 2022, marking an impressive 735% increase since 2000, with an average annual growth rate of 10.58% (FAO FishStatJ, 2024). As of 2022, barramundi was commercially produced in 18 countries, with Thailand (51,893 tonnes), Malaysia (43,735 tonnes), and Taiwan ROC (17,161 tonnes) leading production. Larval rearing of barramundi follows a feeding protocol like many marine species, beginning with the green-water technique during early larval development. Traditional protocols incorporate rotifers, followed by co-feeding with Artemia and manufactured diets (Boeing, 2020). A collaborative study between the BRIN Research Centre, Indonesia, and the SFA Marine Aquaculture Centre, Singapore, evaluated the performance of Natura pRo and ExL feeds under tropical conditions in both a small-scale backyard production system (Figure 1) and in an advanced Mediterranean-style commercial production system (Figure 2). The research focused on two key aspects: 1) The potential for complete rotifer replacement through the early introduction of manufactured feeds during first feeding; and, 2) The impact of various live feed enrichment protocols on larval development. Materials and Methods Trial 1: Backyard production system Asian seabass larvae from a single egg batch were stocked at 16 larvae/L in 4,000 L rearing tanks without pure oxygen supplementation or continuous water exchange. Water temperature was maintained at 28 ± 1°C with a 12:12-hour light/dark photoperiod. All treatments were conducted in duplicate. This trial compared the effects of dry algae, live feed enrichment, and early manufactured feed introduction against a standard protocol using fresh algae and non-enriched live feed, from hatching to 25 days post-hatch (dph). In both the Control and Rotifer Substitution (RS) treatments, algae were provided from 2 to 18 dph. In the Control, rotifers cultured with fresh algae were fed until 19 dph. In the RS treatment, enriched rotifers were fed from 2 to 12 dph at 50% of the Control amount. In the RS treatment, AF Artemia was introduced from 10 to 13 dph, followed by enriched Artemia from 13 to 23 dph. The Control group received non-enriched Artemia from 13 to 23 dph. Different dry diets were used: The Control group received competitor feed from 8 dph onwards. The RS group received the Natura® line from 3 dph onwards (see Figure 3). The trial concluded at 25 dph with the first grading. Trial 2: Advanced production system Asian seabass larvae from a single egg batch were stocked at a higher density (30 larvae/L) in 4,000 L rearing tanks under controlled conditions. This system included pure oxygen supplementation and continuous water exchange, with temperature maintained at 30 ± 0.1°C. The trial evaluated rotifer replacement and early manufactured feed introduction compared to standard protocols from hatching to 21 dph (Figure 3). In both the Control and RS treatments, fresh Nannochloropsis algae were provided from 1 to 14 dph. Both treatments received Adapting Mediterranean Aquaculture Larval Feeding Strategies for Tropical Species: A Case Study of Barramundi V. Carbone, A. Shinn, H. Crieloue, A. van Amerongen, I.N.A. Giri, Haryanti, Y.N. Asih, Sudewi, N.W.W. Astuti, A. Muzaki, K. Mahardika, I. Mastuti, I.G.N. Permana, C.B. Koh, W.L. Quek, Y. He, R. Hidajat, T. Kunthahong, F. Lenzi, T. De Wolf, G. Rombaut and S. Debono FIGURE 1. Layout of a small-scale backyard fish production system used for Trial 1. FIGURE 2. Layout of the advanced commercial fish production system used for Trial 2. (CONTINUED ON PAGE 32)
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