Monthly variations in reproductive indices, egg quality, and larval survival of broodstock snubnose pompano (<em>Trachinotus blochii</em>)

Abstract

This study evaluated the monthly variations in reproductive indices, egg quality, and larval survival of broodstock snubnose pompano (Trachinotus blochii) reared under captivity conditions from January to December. The parameters assessed included gonadal maturation rate, fecundity, egg diameter, egg buoyancy rate, fatty acid composition (SFA, MUFA, PUFA, and HUFA) in egg, fertilization rate, hatching rate, and 3-day larval survival rate. The results showed that May, July, November, and December were the most favorable periods regarding reproductive performance and egg quality, with maturation rates exceeding 70% and hatching rates surpassing 90%. Notably, July recorded the highest fecundity (107,454 eggs/kg female), and larval survival peaked at nearly 60% during this month. These findings highlight the significant influence of time and environmental factors on reproductive success and seed quality. Analyses revealed a strong relationship between egg quality and larval survival, with the nutrient content of eggs, particularly long-chain polyunsaturated fatty acids such as DHA and EPA. Therefore, the study recommends proactively developing seasonally aligned spawning schedules and providing targeted nutritional supplementation to broodstock during maturation to enhance sustainable seed production efficiency for this high-value marine species.