fa <p style="margin-bottom:0cm;margin-bottom:.0001pt;text-align:justify;line-height:120%;text-autospace:none;direction:ltr;unicode-bidi:embed;"><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">In the present study, the effects of<em> Chlorella vulgaris</em> on blood and immunological parameters of Caspian salmon (<em>Salmo trutta caspius</em>) before and after exposure to Viral Nervous Necrosis (VNN) virus were examined. </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">In this regard, </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">four treatments in triplicate were chosen. Groups included one control and 3treatments (T₁, T₂ and T₃).&nbsp; Fish in control group, T₁, T₂ and T₃ were fed diets supplemented with 0, 1&times;10⁸, 2&times;10⁷ and 3&times;10⁶ chlorella/450 g of food respectively, for sixty days. In addition, a virus supernatant was prepared from infected </span></span><span style="color:black;"><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">wild golden grey mullet (<em>Liza auratus</em>)</span></span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;"> and used for virus challenge of </span></span><em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">S. trutta caspius</span></span></em><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">. Virus was injected </span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">intraperitoneal</span></span><span style="font-family:times new roman,serif;"><span style="font-size:12.0pt;">ly and blood samples were collected before and 14 days after the challenge. Immunological (IgM, C_3,C₄, total protein, respiratory burst, albumin and lysozyme) and changes in blood parameters (RBC, WBC, Htc, Hb, MCH, MCHC and MCV) were also measured. Results showed that <em>C. vulgaris</em> could act as a natural immunestimulant. Also, the alteration trend in hematological and immunological parameters showed that experimental fish could be considered to be resistant to VNN virus after exposure and fish treated with <em>C. vulgaris</em> were more resistant in comparison to those in the control group. The dose used in T₁ (1&times;10⁸ chlorella/450 g food) was the most effective approach with significant differences.&nbsp;</span></span></p> Chlorella vulgaris, Blood parameters, Immunological parameters, Salmo trutta caspius, Viral Nervous Necrosis virus 494 510 http://jifro.ir/browse.php?a_code=A-10-1272-228&slc_lang=fa&sid=1 A. Saberi 100319475328460021374 100319475328460021374 No M.J. Zorriehzahra zorrieh@yahoo.com 100319475328460021375 100319475328460021375 Yes H. Emadi 100319475328460021376 100319475328460021376 No S. Kakoolaki 100319475328460021377 100319475328460021377 No S.M.R. Fatemi 100319475328460021378 100319475328460021378 No