Newt
Newts, as with salamanders in general and other amphibians, serve as bioindicators because of their thin, sensitive skin and evidence of their presence (or absence) can serve as an indicator of the health of the environment. Most species are highly sensitive to subtle changes in the pH level of the streams and lakes where they live. Because their skin is permeable to water, they absorb oxygen and other substances they need through their skin. Scientists study the stability of the amphibian population when studying the water quality of a particular body of water.
Newt
Newts form one of three subfamilies in the family Salamandridae, aside Salamandrinae and Salamandrininae. They comprise most extant species in the family, roughly 100, which are classified in fourteen genera: