Study of hematological parameters of silver carp (Hypophthalmichthys molitrix) exposed to sublethal concentrations of Roundup herbicide

Fish are very sensitive to a wide range of chemicals, including herbicides, which can pollute water sources not only through deliberate drainage into the waterways, but also through spraying farms in conventional farming practices which also jeopardizes aquatic ecosystems and living organisms. Roundup is a very useful herbicide in present case study was aimed to investigate the effect of its sub-lethal toxicity on blood indices of silver carp. For this purpose, first with determination of some poison concentration for LC50 calculation, mortality was monitored at 24, 48, 72 and 96 hours and lethal concentarion was measured 9.9 mg/l with probit analysis. Then, a separate experiment was designed according to the LC50 data where fish were put in 4 treatments with triplicate (control group and 12.5, 25 and 50% of LC50 96h) in two periods of 4 and 8 days and after exposure to the herbicide some blood hematological parameters such as hematocrit, hemoglobin, RBC indices, RBC, WBC and differential count of white cells were studied. Results of hematological indices found a significant decrease in RBC, WBC, hematocrit and hemoglobin and also an increase in the number of neutrophils showed by increasing the concentration of the herbicide. The results of this study showed that hematological indices are a sensitive indicator and can be useful to evaluate the effect of herbicides on aquatic organisms.