ABSTRACT
A study was carried
out to investigate the toxicity effects of exposure of aqueous extract of
Chromolaena odorata leave on gill/liver (histological) of juveniles catfish
Clarias gariepinus. The leaves were harvested fresh, air dried for 7 days under
ambient room temperature. 200 healthy juveniles catfish Clarias gariepinus
specimen with average initial weight of 12.40 ± 2.46 cm (mean total length) and
8.26 ± 1.25 g (mean body weight) were exposed to aqueous extract of Chromolaena
odorata leave at the concentration of 50, 100, 150, 200, 250 mg/l respectively.
The physical reactions observed in the fish were: erratic swimming, gasping for
air, loss of reflex, hyperactivities and skin discolorations which were more
pronounced at high concentration and exposure time. The pH and dissolved oxygen
significantly (P < 0.05) de-creased as the concentrations of C. odorata
leaves extract increased. However, the values of Ammonia in the exposed media
significantly (P < 0.05) in-creased as the concentrations of C. odorata
leaves extract increased, compared to the control test medium. A high mortality
rate was recorded, the histologi-cal conditions on gill and liver includes the
deformation of gill tissue with overlapping of secondary lamella and
disintegration of epithelial tissue lead-ing to diffuse mass of the gill
lamella due to rapid cell lysis, gill clogging and gill structure disruption.
Deformed primary and secondary lamella with dis-integrated gill filament,
increasing vasculation, total fusion of gill filament lamella and filament
length variation. Damage became severe with increasing concentration in C.
odorata leaves to fish and exposure, while liver of Clarias gariepinus shows
liver hepatocellular alteration and increase in hepatocyte disintegration,
rupture blood cells in the entire cell with hemorrhage of the vessels and blur
nature with severe breakage due to rupture.