Reproductive Benefits of Dietary Selenium Nanoparticles (SeNPs) in Asian Seabass (Lates calcarifer) Male Broodstock.

Selenium (Se), a critical trace element for human and animal health, is essential for numerous physiological processes, including antioxidant defense, immune function, and reproduction. This study investigated the effects of dietary selenium nanoparticles (SeNPs) at 2 mg/kg on the reproductive performance, Se deposition, antioxidant status, and gene expression in male Asian seabass (Lates calcarifer). Over 120 days before spawning, the male broodfish were fed either a control diet (CD) or a SeNP-supplemented diet (SeD) in triplicate tanks per group. The SeD group exhibited significantly higher gonadosomatic index (GSI), fertilization rate, and hatching rate, along with lower rates of abnormal embryogenesis compared to the CD group (P < 0.05). Selenium accumulation was significantly elevated in the liver and testis tissues of the SeD group, corresponding with increased expression of the hepatic selenop gene. Reproduction-related genes, including ar, p450scc, and cdk1, were significantly upregulated in the testis of the SeD group, indicating enhanced reproductive processes. Antioxidant-related genes, including catalase (cat), superoxide dismutase (sod), and glutathione-s-transferase (gst) were also upregulated in both liver and testis tissues, while catalase activity increased in the testis. In terms of sex steroid hormones, the SeD group displayed significantly higher serum levels of testosterone and progesterone (P < 0.05), suggesting enhanced steroidogenesis. The absence of adverse effects further demonstrates the efficacy and safety of SeNP supplementation at 2 mg/kg. This study highlights the potential of SeNPs to enhance reproductive performance, regulate molecular pathways, and optimize broodstock management in aquaculture.