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
Wu "et al". (2007) found that when larvae are placed in a homogeneous temperature environment, they do not need to use behavioral thermoregulation and instead only use metabolic compensation. However, when placed in an environment with a variation of temperatures, newts will use both behavioral thermoregulation and metabolic compensation. Samajov and Gvozdik (2009) discovered that when adult newts dive at higher temperatures, they reduce the amount of time in their dive in order to reduce the cost on thermoregulation. Samajov and Gvozdik did not take into consideration that newts respire aerially, as well as cutaneously, and so the frequency and the duration of the dives recorded could have been affected by the amount of dissolved oxygen in the water. Adult newts alter the speed in which they dive between descents and ascents. Descents affect thermoregulation by using more energy, and so newts will often choose a passive descent, rather than swimming down to forage for food. When "T. carnifex" ascends, thermoregulation is not as affected because newts have been known to increase their buoyancy by expelling excess gasses. By altering the behavior used as a larvae and when swimming, "T. carnifex" can effectively thermoregulate.