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
The gills have their origins in gill arches 2, 3, and 5; these increase with 3 more bars, that consist of secondary filaments, which create the respiratory organ. In the secondary lamellae there are connective tissues that provide support to the epithelium; these make up the water-blood barrier, in particular where the capillaries are immediately below the basal cells. There are numerous secondary filaments along with the main filaments, which are lengthened to extend the oxygen-catching capability. This increase in surface area counteracts the decreased oxygen available, by allowing greater oxygen uptake. In larval stages, the gills are well-developed with a great number of respiratory lamellae. This adaptation is hypothesized to be an advantage in response to the conditions in an aquatic environment.