Italian crested newt
When newts are inactive or in oxygen-rich environments, respiration can be done through their skin which accounts for 74% of the cutaneous respiration. However, oxygen-poor environments, such as stagnant ponds, pose a threat to the survival of larval newts. This is because oxygen molecules do not readily dissolve in water, and as "T. carnifex" is an immobile animal, extracting oxygen from water is difficult. Newts consequently have external gills at birth that persist until metamorphosis, which assists survival in low-oxygen conditions.
Italian crested newt
Nonylphenol is a large issue for "T. carnifex" because it is a very common toxin found in leakage from sewers into the habitat of the Italian crested newt. Newts are amphibians, and make their habitats in aquatic environments. These environments have been known to sometimes receive the previously discussed sewage leaking. The compounds nonylphenol as well as ethoxylate surfactants can be found in polluted rivers, where the newts reside. The two substances discussed can be transformed, by microorganisms, into compounds which are much more toxic. They are extremely good bioindicators, due to the magnification of these chemicals in the environment demonstrated in the newt. Nonylphenol absorbed through the newts’ skin is especially dangerous because it can result in issues with the reproductive biology as well as cutaneous and osmoregulatory mechanisms.