Amphibians are sometimes called “indicators.” They are called indicators because they are very sensitive to change in their environment.

They breathe through their skin and breathe toxic and non-toxic components with it too.

Nearly 33% of the amphibian species of the world are categorized as threatened on the Red List.

Amphibians are dependent for their survival on a plentiful supply of fresh water that is free of chemical contaminants and harmful microbes

Source: ForumIAS