In some newt species, including the central newt, the aquatic larvae go through a terrestrial stage before later maturing into aquatic adults. Newts in the terrestrial stage are called efts. Many species of newt do not go through the terrestrial eft stage but rather transform from larvae directly into aquatic adults.
Central newt (Notophthalmus viridescens louisianensis) adults and efts have two rows of orange‑red spots. Efts can grow to over eight centimetres long, while the aquatic adult can reach a length of 12.5 centimetres, including the tail. Efts have bright orange or brownish bodies and are more commonly seen than the greenish yellow aquatic adults. The skin of efts is rough, rather than smooth like that of other salamanders. When they emerge from the egg, the larvae have a gold tinge and a black stripe through the eye.
The central newt is the only subspecies of newt found in Ontario west of Lake Superior. The red-spotted newt is about two centimetres larger at maturity, has a lighter back and more spots, and is found south and east of Lake Superior in Ontario. The red-spotted newt’s spots are also encircled with black.
Adult newts are generally found in slow-moving water in ponds and lakes, and along quiet stretches of streams and swamps. The terrestrial eft inhabits the surrounding damp woodlands, usually under logs or bark on the forest floor, and seldom enters water. Both adults and efts spend the winter on land, adults beneath logs or rocks and efts in leaf litter on the forest floor. In some populations, adults remain in the water throughout the winter.
View an interactive map of the known ranges of central newts in Ontario.
Central newts breed in spring. Newts are known for their elaborate courtship displays. Each female can lay 200 to 400 eggs, which are attached to submerged vegetation. The eggs hatch in one to two months, and the newly hatched larvae are less than one centimetre long. By the end of the summer, the larvae will transform into efts and move onto land. When the efts reach maturity in another two to three years, they transform into aquatic adults and return to water. Like salmon, most newts return to breed in the water where they were born. Migrations generally coincide with heavy rainfall.
Efts are carnivorous and feed on a variety of insects. Adult newts may remain active year-round and feed on many aquatic organisms, including insects, small crustaceans and even other amphibian eggs and larvae.
Newts may live for more than 10 years. These animals contain toxins in their skin that are lethal to most predators, except gartersnakes. When a predator threatens a newt, it assumes a posture that displays the bright colour of its underside, which presumably warns the predator that its prey is toxic.
Threats and Trends
Amphibians absorb water, oxygen and nutrients through their skin. Newts, in particular, spend most of their lives in water and therefore need high-quality water to survive. Heavy siltation, agricultural runoff, and pollutants reduce habitat quality. Many newts are killed on roads every spring and fall during migration to breeding ponds. Reporting road-killed newts to the Ontario Reptile and Amphibian Atlas can help researchers identify these critical migration routes.
Current Status and Protections
Neither the Committee on the Status of Species at Risk in Ontario nor the Committee on the Status of Endangered Wildlife in Canada has assessed the status of the central newt. It receives no protection under the Ontario Fish and Wildlife Conservation Act. The International Union for Conservation of Nature lists the global status of the central newt as Least Concern. The species’ status was confirmed in February 2012.
Learn more about reptile and amphibian conservation and what you can do to help these species on our Reptile and Amphibian Stewardship page.