2.4. Fish sampling and blood collection
At the end of the experimental period (8 weeks), fish were not fed for 18 h before being sampled. Four fish from each diet
replicate were removed from the tank and anesthetized with 2-phenoxyethanol (0.2%). Blood samples were collected from
the caudal vein using a hypodermic syringe. The collected blood samples were divided into two sets. One set was mixed with
K2EDTA (at 1.5 mg mL−1 blood) as an anticoagulant for hematological examination and plasma collection. The other set was
left to clot at 4 ◦C for at least 3 h. Plasma was collected by centrifugation of the K2EDTA-treated blood at 9000 × g for 10 min
at 4 ◦C and stored at −80 ◦C for further analysis. The serum was collected by centrifuging the clotted blood at 9000 × g for
10 min at room temperature