Abstract
Giant Trevally (Caranx ignobilis) is gaining prominence as a candidate species for commercial mariculture owing to its rapid growth, adaptability, and market demand. This study reports refinement in induced breeding, larval rearing and nursery rearing (in natural conditions) of the species. Wild-caught sub-adults (50–110 g) were acclimatized and conditioned in recirculatory aquaculture systems (30–34 ppt), improving spawning efficiency and reducing stress. Induced breeding with GnRH analogues resulted in repeated spawnings, with fertilization rates refined from 64 to 92% through selective broodstock management. Larval rearing protocols incorporated copepods (Parvocalanus crassirostris) and microdiets, ensuring higher survival and growth. Transport of 10–15 DPH larvae using oxygen-packed containers recorded >90% survival, and nursery rearing in natural plankton-enriched tanks yielded juveniles of 2.0–2.5 cm by Day 45. These findings demonstrate the feasibility of large-scale seed production and provide a structured framework for expanding Giant Trevally farming in coastal and offshore systems, advancing sustainable mariculture practices.