Hermaphroditism induction of Sub-Lethal Dose of Atrazine and Atrazine-Nitrate on the Egyptian Toad, Sclerophrys Regularis

In this study, atrazine has been shown to act as a potent endocrine disruptor in amphibians either alone or in combination with nitrate under stable laboratory conditions, causing altered gonadal development at the sub-lethal concentrations. A control group and three treatments were tested; atrazine, nitrate, atrazine- nitrate treatments with doses of 300 μg/L, 200 mg/L and their combination, respectively. Atrazine exhibited increase the presence of testicular oocytes TOs in most treated specimens; furthermore, the sizes of seminiferous tubules were decreased compared to control group. Conversely no intersex individuals were detected in the nitrate treatment alone. The combined effects of nitrate and atrazine were not additive or synergistic but were similar to the effects of atrazine in raising the percentage of intersex but with increasing the size of testicular oocyte compared to atrazine alone. On the other hand, the control group in the present study did not contain the rudimentary testicular oocytes and showed normal structures. These gonadal abnormalities may reduce reproductive success and could be a major factor behind amphibian declines. Also, these negative impacts may be a bioindicator alarming the ecosystem disrupting caused by the uncontrolled apply of these chemicals in agriculture