Study on hematological changes and stress indices of Silver carp (Hypophthalmichthys molitrix Valenciennes, 1884) during lethal and sublethal exposure to lead chloride

Importance of the fish health diagnosis will be confirmed by aquaculture industrial development. Blood indices are useful biomarkers to assess the physiological status of aquaculture in response to applied stress and the changes in the fish body exactly in response to pollutants. In this study the lethal concentration of lead was determine in the 38.09 ppm through calculation of carp exposed to lead chloride at 24, 48, 72 and 96 hours with the probit analysis, then in a separate experiment, fish were exposed at the acute and subacute treatments of lead chloride for 96 hours (10 and 50 percent of LC50 96h) and a control group each with 3 replicates were placed.After sampling, hematological and biochemical indices such as hematocrit, hemoglobin, red blood cell, total number of white blood cells and red and differential count of blood cell, glucose, cortisol and total protein were studied. The results showed a significant reduction in red blood cells, hematocrit, hemoglobin and an increase in the number of neutrophils by increasing the concentration of the toxin (P<0.05). Also it was significantly increased of glucose, cortisol observed in biochemical parameters and also a significant reduction in total protein (P<0.05). As a result, it can be stated that heavy metal lead could have physiological lesion and secondary stress response in fihses even under sub acute concentrations.