Newts and salamanders fall into the Urodela order of amphibians and have long tails, elongated bodies and two or four legs, depending on the species. Newts are carnivorous and capable of living in a variety of different habitats. Some newts and salamanders are fully aquatic, others are fully terrestrial and some will divide their time between both land and water. Newts are unique the salamander family in that they return to the water every spring to breed.
Newt eggs do not have shells on them, but are coated by several layers of protective jelly. As many as 200 to 400 eggs may be laid during a single breeding season. The newly hatched newt is already carnivorous in its larval form and will continue to grow consistently until the point where metamorphosis occurs and the adult form is obtained. Its metamorphosis includes a number of different changes that are complex and designed to equip the newt for its upcoming adult life.
Aquatic larvae stage
Newly hatched larvae begin to appear between three and eight weeks after they have been laid. The newly hatched larvae will remain in this stage for three to four months. Aquatic larvae are typically 1.2 cm (1/2 inch) long and green to brown in colour. At this stage, the newt possesses a heart with two chambers and gills to aid in breathing.
During this stage of its life cycle, the newt's heart is growing quickly to accommodate the appearance of a third chamber. The colour of the newt will transform to take on characteristics of the adult. This is also the stage at which lungs begin to form in order to allow the newt to live on land. Toward the end of this stage, terrestrial newt species will leave the water.
In the adult stage, the newt is between 7.5 and 10 cm (3 and 4 inches) long, growing and developing for an additional two to three years. Outer features change as legs, tails and breathing mechanism become stronger. Aquatic newts return to the water during the adult stage. Terrestrial newts return to the water only for breeding purposes.
The breeding season begins in late winter and continues until early spring. All newts return to the water to breed and most newts begin to breed at about 3 years of age. The female will scatter her eggs across a large area, laying only a couple of eggs at a time. Newt eggs are typically laid on the leaves of plants submerged in the water. Once the eggs are laid, the newts are left to fend for themselves.