International Journal of Science and Technology

International Journal of Science and Technology>> Volume 7, Number 9, September 2017

International Journal of Science and Technology

Histopathological Changes in the Gills, Livers and Brains of O. niloticus (TREWAVAS) Exposed to Paraquat in Chronic Bioassay

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Author M. M. Babatunde, Oladimeji A.A, Rafindadi A. H
On Pages 101-110
Volume No. 4
Issue No. 5
Issue Date May 01, 2014
Publishing Date May 01, 2014
Keywords Histopathology, paraquat, O. niloticus, hypertrophy, Oedema.


In the acute toxicity test, the gills of exposed fish showed damage to the filament lamellae and mutilation of gill rakers. In the sublethal assay of this study, the nature of the damage to the gills was more of oedema and hypertrophy of cells than atrophy seen at acute toxicity test. O. niloticus kept in various sublethal concentrations of paraquat, showed liver cell vacuolation which increased with increase in concentrations. The greatest effect was observed at 2.0mg/l where 80% of the cells were necrotic. There was also hepatocytic architecture disruption and loss of cellular details of pancreatic acinar. The fish exposed to paraquat showed pathological changes in the brain tissue ranging from noticeable increase in number of glial cells to vacuolation of neuronal cells, meningitis and encephalitis. All these were dose dependent. All these neurotoxic effects affected the behavior of the fish. The possible connection of these abnormalities with observed behavioural changes is discussed.

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