The first successful land-based larviculture of narrow-barred Spanish mackerel (Scomberomorus commerson) and the assessment of optimal water conditions for larval survival using response surface methodology

Abstract

The narrow-barred Spanish mackerel, Scomberomorus commerson, is a high economic value fishery resource in various parts of the world including Taiwan, but its population has significantly declined in recent years. Developing aquaculture methods for this species could help counteract the dwindling fisheries resources. This study successfully achieved fertilization through onboard artificial insemination, optimized larval survival conditions using response surface methodology (RSM), and conducted two batches of larviculture in land-based ponds while tracking larval development. Artificial insemination was performed on April 18, 2023, and May 12, 2023, aboard a vessel, resulting in fertilization rates ranging from 90–100%. Fertilized egg diameter was 1.04 ± 0.01 mm, with an oil globule diameter of 0.30 ± 0.00 mm. Optimal larval survival conditions, determined using RSM, were found at 25.17°C and 26.54 ppt salinity, achieving a larval survival of 97.42% with a desirability value of 0.974. Larvae began feeding at 3 days post hatch (dph), measuring 3.57 ± 0.07 mm, and grew to 117.91 ± 16.18 mm by 37 dph. Survival rates for the two batches ranged from 0.17–0.23%. This study represents the successful larviculture of narrow-barred Spanish mackerel in land-based culture ponds, marking a significant advancement in aquaculture for this species.