TITLE:
Chronic Exposure to No-Effect Concentration of Diazinon Induced Histological Lesions in Organs of Clarias gariepinus
AUTHORS:
Adekemi Florence Fagbohun, Olufunke Eunice Ola-Davies, Benjamin Obukowho Emikpe, Oluwafemi Obagbemiro, Olanike Kudirat Adeyemo
KEYWORDS:
Diazinon, Histopathology, Clarias gariepinus
JOURNAL NAME:
Agricultural Sciences,
Vol.11 No.7,
July
28,
2020
ABSTRACT: In all parts of the world pesticides have been found in the aquatic ecosystem and
scientific evidence has also shown that they can enter the food chain. Diazinon
is an organophosphate pesticide, widely used in agriculture to control a wide
variety of suckling and leaf eating insects and recently in fish culture to
suppress some parasitic diseases; nevertheless, there is little study on its
adverse effect on fish. In this study, seventy-two (72) apparently healthy
catfish comprising adult and juvenile of both sexes were used to set up
triplicate experimental groups of those exposed to culture water alone (control
group), fish exposed to pre-determined no-effect concentration (0.405 ppm) of
Diazinon (test group). The fish were exposed for 28 days and fish were
sacrificed and organs harvested on days 21 and 28 to determine the effect of
long-term exposure to diazinon on organ histology. Histological changes
observed in diazinon-exposed catfish were hyperplasia and fusion of the gill
epithelium, hyperplasia of mucoid producing cells and aggregation of melanin
pigment in the skin. Histological lesions were also seen observed in other
organs, including severe diffuse cellular swelling and fatty degeneration of
the liver, interstitial congestion of the kidney, carbon deposit on the wall of
the heart and multifocal haemorrhage. The water quality of the control was not
significantly different from that of the test group throughout the experiment.
The lesions detected in cells, tissue, or organs represent an integration of
cumulative effects of physiological and biochemical stressors. The histological
alterations observed in vital organ of fish show that exposure to “no-effect”
concentration of diazinon induced structural damage in fish organs and are
likely to affect the functionality of the organs. For example, the adverse
effect on the gill might disrupt its feeding and oxygen uptake.