What’s the difference between a newt and a salamander?
If you spot a small, long-tailed amphibian near a wooded pond, you’re probably looking at a salamander or newt.
But what is the difference between a salamander and a newt? And how to differentiate them?
Within the tree of lifeSalamanders are a large and diverse group of tailed amphibians. “They belong to the order Caudata, which literally means ‘tailed’ in Latin,” said Karen Kiemnec-Tyburczyassociate professor at California State Polytechnic University, Humboldt, specializing in salamanders. There are a total of 10 families of salamanders, she said. Newts are a subfamily called Pleurodelinae, within the family Salamandridae.
Since all newts are salamanders, there isn’t really a distinct characteristic that separates them from one another. However, some species in the newt subfamily have some interesting traits, Burgmeier said. For example, a number of newts have warty, bumpy skin. “They tend to have rougher skin,” Burgmeier said, in contrast to the smooth, slimy skin of salamanders.
This is probably because newts are the most toxic salamanders; their skin contains numerous venom glands. For example, the skin of a rough-skinned newt (Grainy taricha), a species present in western North America, contains bacteria that secrete tetrodotoxin. This is the same toxin found in Japanese pufferfish and can be fatal if ingested.
“It would be pretty catastrophic if you threw one in your mouth,” Burgmeier said.
Additionally, salamanders generally have a “biphasic” lifestyle, Burgmeier noted, meaning they often begin their lives in water and then move to land. In some newts, this life cycle can be “triphasic”, meaning they begin life in water, have a juvenile.to the east” phase during which they ascend to land, then end their adult life in the water.
An example of this is the eastern newt (Notophthalmus viridescens), a common species in the eastern United States. The newt has a characteristic bright orange juvenile that roams the forest floor (called a red on the left). Efts live on land for about two to three years, equipped with developed lungs and toxins to ward off predators, before finally metamorphosing into an aquatic adult.
However, it is interesting to note that some coastal populations of eastern newts will skip their left instar completely and spend their entire lives underwater. And variations in life cycles are common among newts and salamanders. Many newts in Europe and Asia have a more traditional biphasic lifestyle than triphasic, Burgmeier said.
Likewise, not all newts have bumpy, toxic skin. Many, like the smooth newt (Lissotriton vulgaris), have smooth skin.
One reason for the lack of unifying traits among newts is likely that when herpetology began, naming was not standardized.
“The term ‘newt,’ historically, was used informally as a common name for this type of warty, bumpy newt. [salamanders]”, Kiemnec-Tyburczy told Live Science. “But it turns out they are not each other’s closest relatives. As salamander taxonomy became clearer throughout the 20th century, scientists classified warty and bumpy salamanders and their closest relatives as newts. As a result, the current subfamily harbors a mixture of characteristics.
Diversity also abounds in the order salamanders. There is without lungs salamanders that have no larval stage at all; they develop inside the egg. Some salamanders, axolotlsnever grow beyond the tadpole stage. Around the world, salamander species can also vary from one inch (2.5 centimeters) to up to 6 feet (1.8 meters) long.
Salamanders are “just super cool,” Burgmeier said. He studies the master of the eastern hell (Cryptobranchus alleganiensis alleganiensis), the largest salamander in North America. Their presence and health can tell scientists a lot about water quality. For small newts and salamanders, they can be a key part of the food web, feeding on invertebrates and supporting aquatic and terrestrial ecosystems, Burgmeier added.
“Salamanders have a ton of different things,” Kiemnec-Tyburczy said. “Newts are just a small subset of the entire diversity of salamanders.”
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