Spectrochemical Analysis of Tissues of Frog Dryophytes plicatus Tadpoles (Amphibia: Hylidae) Developing under Lead and Iron Pollution

This study conducted a bioassay on frog tadpoles of the Mexican endemic species Dryophytes plicatus exposed to lead and iron. This species was used because some of its populations live near urban areas that may exposed them to pollutants, such as heavy metals due to industrial processes or mining industry. Specimens in a post-embryonic stage of Dryophytes plicatus were collected in water bodies near El Chico National Park. For the bioassay, the collected samples were grouped into three namely; tadpoles in contact with steel cloves (99% Fe, 1% C); the second group in contact with lead plates; and the last was the control group (without heavy metals). A spectrochemical analysis was held to identify the concentrations of these elements in the liver, intestines, and gills. This study shows that Dryophytes plicatus can bioaccumulate these heavy metals in their tissues, particularly in the liver and the intestine. The concentration of lead and iron was similar in both the control and experimental groups, due to the use of tap water of a mining place, but the concentration in the tadpoles tissues indicates a bioaccumulation process.