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.
Notonecta glauca
Although "N. glauca" live in the water, they breathe atmosphere air and do not have gills. When these insects are diving or resting under the water surface, they create a film of air that surrounds their body. This air film is also known as a superhydrophobic coating or surface, and it prevents the insect from becoming wet. It also reduces the drag (physics) that is created when diving. To be able to create this air film around it, "N. glauca" is covered in hairy structures, except on its head and legs. There are two types of hairs and air retention is maximized by having both types: setae and microtrichia. The most important part in creating an air film is the density of the hairs. "Notonecta glauca" has dense microtrichia and their air film can last up to 120 days. The air film cannot last forever because as an insect respires (breathes), the oxygen partial pressure will decrease and nitrogen partial pressure will increase, causing the air bubble to decrease in size.
"Notonecta glauca" is used as a model organism for friction reduction and air retention. Possible applications for this include reduction of drag in ships.