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.
Smooth newt
After two to three weeks (depending on water temperature), the eggs hatch to a larval form – a tadpole or eft. For a few days, the larvae live off the food reserves contained within their yolk sacs (left over from the egg stage). After this, they start to eat freshwater plankton, and later insect larvae, molluscs, and similar foods (unlike frog and toad tadpoles, newts are carnivorous throughout their lives). 
The newt larvae initially look like small fish fry, but later they become similar to miniature adults, but with "feathery" external gills emerging from behind the head on either side. As the tadpoles mature, they develop legs (front first), and the growth and use of their lungs is matched by a gradual shrinkage of the gills. Thus, the larva gradually shifts from being fully aquatic to possessing a body suitable for a mostly terrestrial existence, the young newt typically leaving the water after 10 weeks. However, some may overwinter in the larval state, only emerging from the water the following year. Smooth newts take around three years to become sexually mature, on average living for six years. Most adult and juvenile newts hibernate over winter in moist, sheltered areas above ground, emerging in the spring.