Abstract
Healthy and active Clarias gariepinus were exposed to acute and sub-lethal concentrations of DDT for a period of 96 hours and 30 days, respectively. The 96 h LC50 was registered as 1.55 mg/l. It has been observed that protein concentration was decreased, and the glucose was elevated in the plasma of treated fish. Sub-lethal DDT exposure has decreased significantly (P<0.05) the level of glycogen in muscle and liver. The DDT has caused a decrease in the counts of erythrocyte (RBC) and leucocyte (WBC), haematocrit (Hct) values and concentration of haemoglobin (Hb). Various hematological indices such as mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were also changed. The concentration of magnesium (Mg) was unchanged but calcium (Ca) was reduced in the blood of exposed fish. The glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) activity was increased in the DDT treated fish. It has been concluded that these effects were more pronounced in higher concentration and in the last period of exposure.