Spotted paddle-tail newt
"Pachytriton" species are stout-bodied, smooth-skinned aquatic newts. Their heads are large and flattened, and they have conspicuous labial folds and short, stubby legs and toes. They breathe through both lungs and skin. 
"P. brevipes" ranges from 5.5 to 7.5 in as an adult. It has prominent labial folds, long digits, and smooth skin, which differs from the tuberculate skin typical of newts.
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.