عنوان مقاله [English]
In order to investigate the effects of different levels of vitamin C in water on rainbow trout (Oncorhynchus mykiss) and lettuce plant (Lactuca sativa) growth indices in an aquaponics system, 90 rainbow trout fishes and 260 seedlings of lettuce were randomly introduced into 9 experimental unites. Treatments were affected by increasing the vitamin C concentration of 0, 15 and 30 mg per liter of water for 60 days. Growth indices of fish showed significant differences (P<0.05) among treatments at the end of experiment. Lettuce growth indices such as leaf length, leaf width, plant height, fresh weight of plant, dry weight of plant, root length and root dry weight were not significant (P≥0.05), but the root fresh weight showed a significant difference between treatments (P <0.05). Biochemical parameters of blood showed significant differences in treatment with 15 mg of vitamin per liter of water compared to other treatments, the highest mean concentration of red blood cells (MCHC) in hemoglobin recorded, 34.13 ± 0.73 g / dl in this treatment as well. Other blood indices such as hematocrit (Hct), Mean Corpuscular Volume )MCV(, hemoglobin (HGB), red blood cell count (RBC) and mean corpuscular hemoglobin (MCH) were not significantly different (P≥0.05) among treatments. It was indicated that adding 15 to 30 mg L-1 of Vitamin C to water, have a positive effect on the biological conditions of the plant and fish in an aquaponic culture of rainbow trout and lettuce.