Effect of copper on hematological indices changes of farmed Silver Carp (Hypophthalmicthys molitrix)

In this study, in order to investigate the acute toxicity of heavy metal copper on blood indices of Silver Carp (Hypophthalmicthys molitrix), 135 fish were exposed to 0, 5 and 10 mg/L of Cu (NO3)2. 24h- LC50 of Cu2+ was 2.5 mg/L. Results showed that white blood cells count (WBC) decreased significantly with the increase of copper concentration (P<0.05). Red blood cells count (RBC) showed no significant difference (P>0.05). Hemoglobin (Hb) levels was decreased with the increase of copper concentration and time (P<0.05). Hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC) and mean corpuscular hemoglobin (MCH) were decreased significantly (P<0.05) with the increase of time. Triglyceride level changed significantly (P<0.05), but cholesterol level didnot. Glucose levels changed significantly with the increase of copper concentration in 12 and 24 hours (P<0.05). Total protein levels decreased significantly at 5 mg/L treatment in 24 hours. Differential count of leukocyte showed significant decrease in lymphocyte and monocyte and significant increase in neutrophil. Based on these results, copper induced significant changes in many blood indices and showed acute toxicity in Silver Carp. Therefore, this species has a low resistance to copper toxicity.