en aquaculture aquaculture پژوهشي Orginal research papers <strong><span lang="TR" style="font-size:10.0pt"><span calibri="" style="font-family:"><span style="color:black">This study investigated the effect of silver nanoparticles (AgNPs) and Chlorella vulgaris nanoparticles (ChVNPs) on growth, oxidant stress, bioenergetics, muscle amino acids, and profitability in Nile Tilapia (Oreochromis niloticus) under hypoxia and cold stress. We divided 180 fingerlings (</span></span></span></strong><span lang="TR" style="font-size:10.0pt"><span calibri="" style="font-family:"><span style="color:black">10.03&plusmn; 0.5 g)<strong><span calibri="" style="font-family:"> into four equal groups with three replicates (15 fish /replicate). Nile tilapia received basal diet (control), basal diet with ChVNPs (5g/kg diet), basal diet with AgNPs (0.02 mg/kg diet), or basal diet with both ChVNPs and AgNPs (mixed group). Each group was subdivided into three subgroups with stress exposure (hypoxia or cold) or without stress (control). After 45 days, growth performance and feed utilization of fish exposed to AgNPs showed significant improvement. The mixed treatment significantly (<i>p</i>˂0.05) reduced the stress-induced elevation of total cholesterol (TC), triglycerides (TG), and cortisol. Hypoxia and cold stresses induced oxidant stress marked by significant reduction (<i>p</i>˂0.05) in SOD, CAT, and GSH levels and significantly increased in MDA, NO, and GSSG. </span></strong>Basal diet with both ChVNPs and AgNPs (mixed group) <strong><span calibri="" style="font-family:">significantly altered the oxidant-antioxidant status. The hypoxia and cold stress modulated the muscle amino acid profile by reducing ISO, LEU, METH, and TAU and increasing LYS. In </span></strong>basal diet with both ChVNPs and AgNPs (mixed group)<strong><span calibri="" style="font-family:">, muscle ARG, HIS, LYS, PHEN, VAL and ASP were significantly decreased (<i>p</i>˂ 0.05) in compared with other treated groups, whereas; ISO, LEU, METH, TUA, SER, GLY, ALA, and PRO were significantly increased (<i>p</i>˂0.05) in compared with other treated groups. Stress significantly decreased (<i>p</i>˂0.05) muscle ATP and increased ADP and AMP that were modified by the </span></strong>basal diet with both ChVNPs and AgNPs (mixed group)<strong><span calibri="" style="font-family:">.&nbsp; The fish diet supplemented with AgNPs achieved the highest economic profits compared to other treatments. However, </span></strong>basal diet with both ChVNPs and AgNPs (mixed group) <strong><span calibri="" style="font-family:">is recommended to alleviate adverse stressors effect.</span></strong></span></span></span> Antioxidant capacity, Amino acid profile, Cold and hypoxia stress, AgNPs, Muscle ATP 887 912 http://jifro.ir/browse.php?a_code=A-10-5007-1&slc_lang=en&sid=1 A.F. Matter ayamatter29@yahoo.com 100319475328460056856 100319475328460056856 Yes Aquatic Animal Medicine Dept, Faculty of Vterinary Medicine Benha University E.I. Soror emansoror@yahoo.com 100319475328460056857 100319475328460056857 No Aquatic Animal Medicine Dept, Faculty of Veterinary Medicine Benha University A. Shehab Ahmed.shehab@fvtm.bu.edu.eg 100319475328460056858 100319475328460056858 No Dept. of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine Benha University O.A. Farid ebntaimya@yahoo.com 100319475328460056859 100319475328460056859 No Dept. of Physiology, National Organization for Drug Control and Research, Giza, Egypt A.M. Abd-El Hamed amiraefeky@fvtm.bu.edu.eg 100319475328460056860 100319475328460056860 No Dept of Animal Wealth Development, Faculty of Veterinary Medicine, Benha University Z.H. Abo-Gamil zienbhamdy@yahoo.com 100319475328460056861 100319475328460056861 No Dept of Animal Wealth Development, Faculty of Veterinary Medicine, Benha University A. Khalid akh_ghalia@yahoo.com 100319475328460056862 100319475328460056862 No Dept. of Basic Engineering Sciences, Faculty of Engineering (Shoubra), Benha University, Shoubra, Egypt. T. Soliman tarek.attia@fsc.bu.edu.eg 100319475328460056863 100319475328460056863 No Physics Department, Faculty of Science, Benha University H.A. Youssuf Ahmedyoussuf140@yahoo.com 100319475328460056864 100319475328460056864 No Aquatic Animal Medicine Dept, Faculty of Veterinary Medicine Benha University