en aquaculture aquaculture پژوهشي Orginal research papers <span style="font-size:11pt"><span style="line-height:104%"><span style="font-family:Calibri,sans-serif"><span lang="TR" style="font-size:12.0pt"><span style="line-height:104%"><span new="" roman="" style="font-family:" times=""><span style="color:black">The aim of this investigation is to evaluate the effects of <i>Artemia urmiana</i> metanauplii enriched with a premix extract of brown macroalgae including <i>Padina australis</i>, <i>Sargassum ilicifolium</i>, and <i>Stoechospermum marginatum </i>(macroalgae premix extract; MPE) on growth performance, survival, carcass quality traits, and antioxidant properties of <i>Litopenaeus vannamei </i>(PL₁₅). A total of 1200 PL₁(19&plusmn;0.97 mg) were randomly divided into 4 groups (100 individuals in each group (in triplicate)). The control group was fed only with non-enriched metanauplii (MPE₀) and other groups were fed with metanauplii enriched with 200 (MPE₂₀₀), 400 (MPE₄₀₀), and 600 (MPE₆₀₀) mg L^-1 for 15 days. Our findings revealed that the highest specific growth ratio (SGR), percentage weight gain (WG), protein efficiency ratio (PER) and dry matter were recorded in the group fed with MPE₆₀₀-enriched metanauplii. The feed conversion ratio (FCR) in the group fed with MPE₆₀₀ was less than in other experimental treatments (<i>p</i><0.05). The highest levels of polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), a<span style="background:white">rachidonic acid</span>(ARA), total sterols, and total amino acid content were observed in the shrimp fed with metanauplii enriched with MPE₆₀₀ (<i>p</i><0.05). The phenol, flavonoid, superoxide dismutase (SOD), and c<span style="background:white">atalase</span> (CAT) contents were increased by increasing levels of MPE in themetanauplii diet (<i>p</i><0.05). This study demonstrates the positive effect of metanauplii enrichment with 600 mg L^-1MPE on growth performance, carcass quality, and antioxidant properties of <i>L.vannamei</i>.</span></span></span></span></span></span></span> Litopenaeus vannamei, Artemia enrichment, seaweed, Live feed, Growth 109 132 http://jifro.ir/browse.php?a_code=A-10-82-26&slc_lang=en&sid=1 P. Akbary paria,akbary@gmail.com 100319475328460051274 100319475328460051274 Yes chabahar maritime university A. Ajdari a.ajdari2020@gmail.com 100319475328460051275 100319475328460051275 No Agricultural Research Educations andExtension Organization (AREEO), Iranian Fisheries Science Research Institute (IFSRI), Chabahar OffshoreFisheries Research Center, Chabahar, Iran S. Dutta 100319475328460051276 100319475328460051276 No Sultan Qaboos University, College of Agricultural and Marine Sciences, Department of Marine Science and Fisheries, P. O Box 34 Al-Khoud 123, Sultanate of Oman.