Recently, using natural immuno stimulates developed for fishes to increase immunity, make resistance to disease and growth improvment. In this study, the effects of Spirulina meal as a stimulant of the immune system was examined on growth, hematological, the intestinal bacterial flora and carcass composition on macro fish ( Labidochromis caeruleus ). For this purpose 225 individual of macro fish. (average weight of 2.97g) were randomly distribution in to 5 groups (of 15, each with three replications). Fish were fed based on five diets containing different amounts of Spirulina meal (0, 5, 15, 45 and 90 g/kg) for 60 days. At the end of the experiment, growth, hematological, intestinal flora bacteria and carcasses analysis indices were measured. Results showed significant different (P 0.05) in growth parameters (final weight, weight gain, percent of body weight gain, protein efficiency rate and protein production value) among different levels of spirulina in the diet.Moreover the results were indicated a significant difference in some hematological parameters such as hematocrit, red blood cells and white blood cells counts (P 0.05). Plasma levels of albumin, cholesterol, triglycerides, glutamic oxalic acetic transaminase, glutamic pyruvic transaminase, lactate dehydrogenase and alkalin phosphatase showed significant difference amoung (P 0.05). Other biochemical parameters such as total protein, globulin and glucose did not show any significant change. Intestinal flora analysis showed significant differences in the total number of bacteria that the highest value was observen in the fish fed on 45g/ kg (P 0.05). Carcass quality analysis showed no significant differences between groups although the protein and moisture leveles were changed significantly (P 0.05). Based on the results it could be recommended to add 15g/kg diet of spirulina to the macros diet to improve growth performance some hamatological and serum biochemical changes. Keywords : hematology, Plasma biochemical parameters, bacterial flora, macro fish ( Labidochromis caeruleus )
