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
Oxygen consumption has normally been determined to be the most convenient and relevant measure of metabolic activity. With very few exceptions, oxygen consumption is reduced in response to starvation and physical inactivity, and increased in fed and active animals (Hawkins, 1995). Basal maintenance metabolism in ectotherms is relatively unchanged in response to variations in atmospheric temperatures, which would be advantageous to the newt’s survival in both their aquatic and terrestrial environments where temperatures can rapidly shift throughout the year.