Effects of MS222 on hematological indices of in anesthetic and lethal concentration

The aim of this study was to compare different anesthetic and lethal concentrations of MS222 on blood parameters of Arabibarbus grypus. For this purpose, 18 pieces of fish with an average weight of 150 5.5g were divided into 3 types of treatments: 1) without anesthesia (control), 2) the treatment with a concentration of 750 mgL-1 of anesthetic agent, and 3) treatment with a concentration of 6250 mgL-1 used for lethal dosage. Blood samples were taken from control, anesthesia (at 0, 6, 12 and 24 hours after anesthesia) and lethal treatments. Hematological parameters including the number of red (RBC) and white blood cells (WBC), hematocrit, hemoglobin, MCV, MCH and MCHC were determined. Hematocrit percentages and hemoglobin levels in the 6 and 12 hours treatments showed a statistically significant decrease compared to the control, 0 hour and lethal concentrations (P<0.05). Overall counts of RBC in all treatments except the 6 hours treatment showed a significant increase (P<0.05). MCH and MCV showed a significant decrease in the treatments of 12 and 24 hours compared to the control (P<0.05). MCHC and the percentage of monocytes in all treatments were higher than control (P> 0.05). Overall WBC count and heterophil content decreased in 0 to 6 hours, and in the other treatments, there was an increasing trend (P<0.05). Overall, the results showed that anesthesia with MS222 caused slight stress in the fish. This stress caused an initial disturbance in blood parameters that was triggered by a stress response defense and then returned to normal by the adaptation process after 24 hours, so the use of this anesthetic in aquaculture research is unhindered.