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.
Eastern newt
The eastern newt ("Notophthalmus viridescens") is a common newt of eastern North America. It frequents small lakes, ponds, and streams or near-by wet forests. The eastern newt produces tetrodotoxin which makes the species unpalatable to predatory fish and crayfish. It has a lifespan of 12 to 15 years in the wild, and may grow to five inches in length. These animals are common aquarium pets, being either collected from the wild or sold commercially. The striking bright orange juvenile stage, which is land-dwelling, is known as a red eft. Some sources blend the general name of the species and that of the red-spotted newt subspecies into the eastern red-spotted newt (although there is no "western" one).