Newts, known as salamanders, are amphibians made up of more than 550 living species. They live in the continents of the northern hemisphere and in northern areas of South America. Salamanders live part of their lives in water and part on land, especially in humid areas like forests. It is a large, robust-looking amphibian with a tail, normally measuring from 12 to 23 centimeters, tail included.
Its head is almost as wide as it is long, somewhat flattened and normally with a rounded nose, though in some specimens the nose is somewhat pointed. They have large, noticeable bumps called parotid glands. Its eyes are large and bulging with dark brown irises. Their legs are short and thick with several recessed toes. Its tail is also short, with a rounded section. The length of its tail does not surpass the combined length of its head and body.
The skin of its back and sides is smooth and shiny, black with irregular yellow spots, coloration that varies according to geographical region. There may be cases in which practically no yellow is observed, and others that are predominantly yellow or have yellow stripes. Its throat and belly have yellow spots but not nearly so numerous, and they are a less intense color on the black background. For breeding, they fertilize externally, while other species have internal fertilization despite the absence of a sex organ in males.
They exhibit larval development until adulthood, when its external gills are replaced by lungs. Some species remain aquatic their whole lives, while others return to the water intermittently, and others are completely terrestrial in their adult life. Principally, they feed on prey between 4 and 20 mm long, such as worms, earthworms, snails and insects. The salamander is accustomed to a nocturnal, terrestrial life, making its movement at dusk and dawn, and also by day in rainy weather.
The salamander begins its annual activity with the first autumn rains after spending the summer in a period of inactivity. When captured and handled, it secretes a thick white liquid that produces irritation in humans when it comes in contact with the mouth, eyes or nose. Superficially, the salamander looks like a lizard, but it is easy to differentiate because it has no scales. If the salamander loses a limb, it can regenerate it. This ability grants some species greater flow in escaping from potential predators.
The salamander is a mythological monster and a basic symbol of alchemy. These mythic origins could be due to its amphibian condition and that it lives part of its life in the water and part on land. The earliest fossil records of salamanders correspond to specimens of the Karauridae clade. Salamanders in the wild tend to live approximately 20 years, although in captivity they can live up to 50 years.