O USO DE BIOMARCADOR MORFOLÓGICO E GENOTÓXICO PARA AVALIAR EFEITOS DE CONTAMINANTES AGRÍCOLAS SOBRE GIRINOS

Abstract

Amphibians are sensitive to environmental changes due to the biphasic life cycle that exposes them to aquatic and terrestrial environments, they are especially sensitive to endocrine disrupters and chemical agents that imbalance the functioning of the endocrine system, leading to neurological, immunological and, above all, reproductive problems. So organisms, like anurans, due to sensitivity to environmental contaminants, can be used as bioindicators of environmental quality. Among the most studied biomarkers in anuran amphibians there is have the micronucleus, which is an effective and widely used test to detect genotoxic effects in these animals, and more recently studies have begun with melanophores that are cells originated from the neural crest which are pigmented and are present in the skin and covering organs and membranes of these species. In Chapter 1 it is proposed the use of cutaneous melanophores present in the larvae of anurans to evaluate the effects of agricultural contaminants on these organisms, with three questions to be answered: in which environment were the animals most affected in relation to the effects of agricultural contaminants? Which species had a greater sensitivity in the areas sampled and finally if the evaluation of the body darkening of the tadpoles can be proposed as biomarker of the effect of these contaminants on the tadpoles population. A total of 60 tadpoles of two species: Dendropsophus minutus and Leptodactylus fuscus were collected in three environments: two anthropates (farm with soybean/corn cultivation and sugar cane plant) and a preserved environment, the Emas National Park. There was variation in the pattern of pigmentation of animals from agricultural areas when compared to animals from anthropic environments, and the soybean/corn environment was the major promoter of body darkening. We conclude in this way that the analysis of body darkening can be used as a biomarker of the effects of agricultural contaminants.