Abstract
This experiment was carried out to investigate the effect of Siam Weed (chloromelena odorata) on the heamatology of Clarias gariepinus juvenile. A total of one hundred and fifty (150) juvenile of Clarias gariepinus were randomly assigned to different concentrations of C. odorata leave aqueous extract in a completely randomize design (CRD). The concentrations were 50mg/l, 100mg/l, 150mg/l, 200mg/l. Distilled water (0.00 mg/l) was used as the control. The fish exhibited stressful behavior which was higher as the concentration of Chromolaena odorata leave extract increased. There was a gradual decrease with time until a state of calmness, which was subsequently followed by death. The effect on 96hr exposed period was recorded and blood samples collected at 24hr and 96hr interval. Result on hematological parameters revealed significant difference (P<0.05) among treatments with increase in exposure time for all the blood parameters. C. odorata at increased concentrations affected the behavior and hematology of C. gariepinus.