“…The research and application of medicinal plants with immunostimulatory and antiviral properties in aquaculture are attracting more and more attention (Beltrán et al, ; Reverter, Bontemps, Lecchini, Banaigs, & Sasal, ). There have been many studies focusing on medicinal plants or their ingredients as additives in fish diet, which showed beneficial effects, including promoting growth, invigorating health, weight gain, enhancing the defence mechanisms and immune responses (Awad & Awaad, ; Galina, Yin, Ardó, & Jeney, ; Hu et al, ; Newaj‐Fyzul & Austin, ; Vallejos‐Vidal, Reyes‐López, Teles, & MacKenzie, ). However, a few studies about the medicinal plants or ingredients against grouper iridoviral infection are carried out.…”