Larva development and reproductive system effects of maneb and methoxychlor on Bufo bufo (Linnaeus, 1758) and Bufo viridis Laurenti, 1768 (Salientia: Bufonidae) populations

At this study, were investigated acute and chronic toxic effects of maneb and methoxychlor pesticides on Bufo bufo and Bufo viridis larvae which lives in our country. Acute toxicity experiments, 10-5000 µg/l maneb and 1-100 µg/l doses range methoxychlor, 21st stage larvae were appilied for 120 hours. In chronic toxicity experiments, 0,1-10 µg/l maneb and 0,01-1 µg/l dose range methoxychlor, 21st stage larvae were applied. Chronic toxicity experiments, for maneb 35-55, methoxychlor took 35-57 day range on Bufo bufo larvae. Chronic toxicity experiments belonging to maneb pesticides 74-80, 74-88 day range took for methoxychlor on Bufo viridis larvae. As a result of acute experiments, were found that maneb and methoxychlor pesticides caused by morphological and histopathological changes at larvae. Curvature of the vertebrae, visceral edema and tail deformations are observed morphological findings. Lamellar fusions of the gills, liver necrosis, pronephric tubule deformations, deteriorations of the somite formation and visceral edema are significant histopathological findings. As a result of chronic experiments carried out until the larvae complete to metamorphising were shown that pesticides suppressive effects on growth and development. In addition, maneb and methoxychlor to be effective on gonadal development and sex ratio variation of larvae were observed. These effects on larvae occur that pesticides as the result of endocrine disruptive affects. Taken together the findings of acute and chronic toxicity experiments, were found that maneb and methoxychlor pesticides have negative effects of development and gender characteristics on Bufo bufo and Bufo viridis larvae.