2.6. Blood sample collection
At the end of the experiment, 3 fish were sampled randomly
from each tank and were anaesthetized by clove solution and about
2 ml of blood was drawn from the caudal vein, using a nonheparinized
syringe, after they were starved for 24 h. Then, blood
samples were introduced to both heparinized and non-heparinized
tubes in order to perform hematological and Immunological
studies, respectively. For serum isolation, blood samples in nonheparinized
tubes were centrifuged at 1000 g for 5 min in order
to separate the plasma. The latter was stored at 20 C for lysozyme
activity test [23]