Atrazine modulates epithelial cell proliferation and alters fish gill morphology.

Fish gills are composed of arches that support filaments where gas exchange takes place, allowing fish breath. Number and length of lamellae determine the total respiratory area, that varies according to the feeding habits, biology, behavior and habitat of each species. Morphology lamellae changes, caused even by contaminants in the water, can promote tissue damage that are harmful to the animal`s survival. Pesticides used in agriculture, especially if used indiscriminately and incorrectly, are the main cause of histopathological lesions in fish, even if contact is prolonged, affecting various physiological, metabolic and morphological processes. Fish are good water quality bioindicators as they respond in many ways to contamination and the gills are considered one of the main organs affected, and because they have direct contact with the external environment.