en aquaculture aquaculture پژوهشي Orginal research papers A feeding trial was conducted for sixty days to determine the effect of dietary <em>Aloe vera</em> on parameters related to growth rate, health status and hematological parameters of shirbot (<em>Tor grypus</em>). Two hundred and forty fish weighing 50-60 g were randomly subjected to four different treatments, including a control, T1 (0.1% of <em>A. vera</em>), T2 (0.2%) and T3 (0.5%) in triplicate. Hematological parameters and some growth parameters, including the body weight, total length, condition factor, feed conversion ratio, feed efficiency, specific growth rate and protein efficiency ratio were measured. Administration of fish to different concentrations of <em>A. vera</em> extract led to significant (<em>p</em><0.05) increase in total erythrocyte count, packed cell volume, and hemoglobin when compared with the control group. Mean corpuscular hemoglobin concentration were increased only in T2 and T3 in comparison with the control. When animals received 5% of <em>A. vera</em> daily, they showed a significant increase (29%) in white blood cells (<em>p</em><0.05). Growth parameters were improved with the addition of different concentrations of <em>A. vera</em> to fish food. According to the results obtained, it might be concluded that feeding this species with <em>A. vera</em> extract could likely enhance growth rate and also hematological parameters. Aloe vera, Growth parameters, Hematological indices, Tor grypus 445 456 http://jifro.ir/browse.php?a_code=A-10-1096-1&slc_lang=en&sid=1 M. Safari 100319475328460030290 100319475328460030290 No Department of Fisheries, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran M. Chelehmal Dezfouli Nejad 100319475328460030291 100319475328460030291 No Department of Fisheries, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran M. Mesbah 100319475328460030292 100319475328460030292 No Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran A. Jangaran Nejad abdolhossein.jangaran@gmail.com 100319475328460030293 100319475328460030293 Yes Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran