en aquaculture aquaculture پژوهشي Orginal research papers This study was conducted in two experiments. Experiment 1 aimed to investigate the growth promoting and anti-oxidative effects of <em>Azolla nilotica</em> (AZN) and <em>Spirulina platensis </em>(SP) in <em>Oreochromis niloticus</em>. Seven fish groups (G1-G7), each in three replicates, were fed a basal diet (control), AZN 5%, AZN 10%, SP 0.5%, SP 1%, a mixture of<em> Azolla nilotica</em> 5% and <em>Spirulina platensis </em>1% (AZN 5 %-SP 1% mix), and a mixture of<em> Azolla nilotica</em> 10% and <em>Spirulina platensis </em>1% (AZN 10% - SP 1% mix), respectively, for 3 months. The results showed a significant increase in growth indices (weight gain, specific growth rate, average length gain, feed efficiency ratio), and a decrease in the feed conversion ratio in all supplemented groups compared to control. Hepato-somatic index in G4 and G5 groups, and intestinal-somatic index in G4 - G6, and in G5 and G6 were obviously higher than control. Spleno-somatic index and antioxidant enzymes (<a name="OLE_LINK1">GSH-px</a>, SOD and CAT) markedly increased in G5 and G6 compared to control. Significant increase (<em>p</em><0.05) in white blood cells was recorded in G2 and G4. Experiment 2 verified the effect of one-month supplementation of SP 1% on males and females <em>O. niloticus </em>fecundity. Males fed with SP 1% had an enhanced fertility as indicated by an increase in sperm density, spermatozoa motility and livability rates compared with the control. There was a significant increase in eggs number and the fecundity index in unripe females and a tendency of egg size to increase in ripen fish. It could be concluded that SP 1% and AZN 5% supplementation is advantageous to improve <em>O. niloticus </em>growth and fecundity<em>.</em> Antioxidant enzymes, Azolla nilotica, Growth parameters, Fecundity, Nile tilapia, Spirulina platensis 846 862 http://jifro.ir/browse.php?a_code=A-10-3361-1&slc_lang=en&sid=1 A. El-daim amiramohammed429@yahoo.com 100319475328460040338 100319475328460040338 No Department of Aquatic Animals Diseases and Management, Faculty of Veterinary Medicine, Benha University A. El Asely amlvet@yahoo.com 100319475328460040339 100319475328460040339 No Department of Aquatic Animals Diseases and Management, Faculty of Veterinary Medicine, Benha University M. Kandiel mohamed.kandil@fvtm.bu.edu.eg 100319475328460040340 100319475328460040340 No Department of Theriogenology, Faculty of Veterinary Medicine, Benha University E. Abd El-Gawad dreman_2010@yahoo.com 100319475328460040341 100319475328460040341 No Department of Aquatic Animals Diseases and Management, Faculty of Veterinary Medicine, Benha University H. Elabd hiam_abd@yahoo.com 100319475328460040342 100319475328460040342 No Department of Aquatic Animals Diseases and Management, Faculty of Veterinary Medicine, Benha University A. Shaheen shaheen_aa@yahoo.com 100319475328460040343 100319475328460040343 Yes Department of Aquatic Animals Diseases and Management, Faculty of Veterinary Medicine, Benha University A. Abbass amanyabbass3@fvtm.bu.edu.eg 100319475328460040344 100319475328460040344 No Department of Aquatic Animals Diseases and Management, Faculty of Veterinary Medicine, Benha University