Impact of some endocrine disrupting organophosphrous insecticides on nile tilapia (oreochromis niloticus)‎

Abstract EN

Dimethaote treated Oreochromis niloticus females showed a significant decrease of gonadosomatic index at day 90 and at day 30 and 60 for males.

On the other hand, in malathion treated group females revealed no significant difference in gonadosmatic index.

While, in males, there was a significant decrease along the experimental period, 90 days compared to the control.

Hepatosoamtic index of both females and males treated with dimethaote and malathion revealed no significant difference during the experimental period.

Plasma testosterone and estradiol decreased in dimethoate treated males at day 90, and at day 30 and 60 in malathion treated group than the control.

In female, plasma estradiol decreased at day 30, 60 and 90 in dimethoate treated group with a higher increase in testosterone hormone at day 60.

While, in malathion treated group females revealed a decrease in plasma estradiol at day 30 and 60 with an increase in testosterone hormone at day 30 and 60 than E2 hormone.

Histological examination of gonads revealed pyknosis and degeneration with decrease in diameter of seminiferous tubules in male of both treated groups.

Atretic oocytes and necrotic oocytes were recorded in females of both treated groups.

Liver of all treated groups with dimethaote and malathion in males and females showed necrosis of hepatopancrease with hepatocytes vacuolation and focal hepatic haemorrhage and haemosiderosis indicating liver intoxication.

In conclusion, endocrine disrupting effect was more clearly observed in malathion treated males than that of dimethaote, through alteration in sex steroid hormones and decreased gonadosomatic index.