Abstract
Specimens of Heteropneustes fossilis were treated with various levels of malathion and its 96 h LC50 value was determined. The effects of sub-lethal concentrations of insecticide on hematological and biochemical profile of Heteropneustes fossilis were also registered. The 96 h LC50 value obtained was 8.81 mg/l. Exposure of sub-lethal doses (0.44, 0.88 and 1.76 mg/l which are 5, 10 and 20% of the LC50) of malathion to Heteropneustes fossilis for 3 weeks demonstrated that the toxicant had a detrimental effect on the blood profile of fish. Blood cell (Erythrocyte and leucocytes) counts (from 1.66 to 1.44 cell x 10(6) x mm(3) and 37.93 to 30.24 cell x 10(3) x mm(3); respectively), haemoglobin (Hb) level (from 6.21 to 3.54 g/dl) and haematocrit (Ht) estimates (from 34.26 to 30.52%) were reduced in the fishes exposed to malathion. Elevated level (from 46.25 to 92.45 mg/100 ml) of glucose and decreased quantity (29.95 to 24.25 g/dl) of protein in plasma was registered. Glycogen content in muscle and liver was also decreased. The activity of enzymes glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) were high in the fish treated with pesticide. The possible causes for variations in the different parameters were identified and discussed. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.