A newt is a type of salamander, but the terms describe different levels of classification. Both newts and salamanders are tailed amphibians characterized by four limbs and a long tail, requiring moist environments to survive. The confusion arises because the name “salamander” applies to the entire order of tailed amphibians, while “newt” refers only to a specific subgroup within that order. Understanding their biological family tree and how their lives unfold helps to clarify the relationship between these often-confused creatures.
Where Newts Fit in the Salamander Family
All newts are classified as salamanders, but the reverse is not accurate, much like all poodles are dogs, but not all dogs are poodles. The specific family that contains all newts is known as Salamandridae, often referred to as the “true salamanders.” Within the Salamandridae family, newts are further grouped into the subfamily Pleurodelinae. This means that newts are simply one specialized lineage of true salamanders that have evolved a particular set of traits, primarily related to their life cycle and habitat preference. Other groups within the Salamandridae family, such as the fire salamanders, are considered true salamanders but are not classified as newts.
Key Differences in Adult Appearance
The physical appearance of an adult newt often displays adaptations for an aquatic lifestyle, which distinguishes it from many of its terrestrial salamander relatives. Newts typically develop a prominent, vertically flattened tail, sometimes called a keel, designed to act as a powerful rudder for swimming. In contrast, many highly terrestrial salamanders retain a more rounded or cylindrical tail shape, which is less efficient for propulsion in water.
Newt skin texture also provides a noticeable difference, especially when the animal is out of the water. Newts, particularly those in a terrestrial phase, often have a dry, granular, or warty texture. Many other salamander species possess skin that is notably smooth, slick, and moist. Both types of skin are glandular and permeable, which allows for cutaneous respiration, or breathing through the skin.
Adult newts that spend significant time in water may also exhibit shorter limbs and webbed feet to aid in swimming. This feature is less common in terrestrial salamanders, which tend to have longer, more defined digits better suited for walking or burrowing in soil. This suite of physical traits—the paddle-like tail, rougher skin, and aquatic limb adaptations—are all visible cues that suggest the animal is a newt rather than another type of salamander.
How Their Life Cycles Diverge
The most significant difference between newts and many other salamanders lies in the complexity of their metamorphic journey after hatching. Newts are well-known for undergoing a rare three-stage life cycle. After the aquatic larval stage, they develop into a terrestrial juvenile phase known as the “eft.”
The eft stage is an extended land-dwelling period that can last anywhere from one to three years, during which the newt is often brightly colored and lives exclusively on the forest floor. The skin of the eft becomes rougher and less permeable, allowing it to survive away from the water for a prolonged time. Newts often possess highly toxic skin for defense, especially during the eft stage.
Many other salamanders transition directly from the aquatic larval form to a terrestrial adult, without this prolonged, distinct juvenile land phase. Once the newt eft matures, it migrates back to a pond or slow-moving water source, transforming into the adult newt. This final aquatic adult stage often involves the skin becoming smoother and the paddle-like tail redeveloping, preparing the animal to live a semi-aquatic or fully aquatic life for breeding.