If you’re an amphibian enthusiast, you’ve probably heard this phrase at some point: “All newts are salamanders but not all salamanders are newts.” Does trying to make sense of this cause smoke to come out of your ears? You’re not alone.
To shed some light on this conundrum, let’s first consider a bit of taxonomy. Within the Class Amphibia there are three Orders: Caudata, Anura, and Gymnophiona. Caudata refers to the salamanders; species that retain their tails as adults and have four legs. These differ from the Anurans (frogs) which lose their tails as adults and the Gymnophionans (caecilians) that are legless. The order Caudata includes several families, one being Salamanidrae. Newts belong to this family, hence the phrase all newts are salamanders. So what makes a salamander not a newt? Newts can typically be distinguished by their rough, dry skin, whereas their salamander relatives possess slimy and moist skin. Costal grooves – grooves on the sides of some salamanders which increase surface area for water transport across the skin – tend to be indistinct in newts but quite noticeable in many salamander species. Additionally, many newt species possess defensive skin toxins that serves as a line of defense. The juvenile phase of the Eastern Red-Spotted Newt (commonly known as the red eft) for example, signals its unpalatability to predators through its bright orange coloration.
Now this is where things get more interesting… If you think back to warmer times, like late summer for example, it is quite common to see these little efts traversing the forest floor. They are easy to see with their bright colors, but nothing seems to bother them (other than a tickled herpetologist picking one up to take a closer look from time to time). With most of our other salamander species, you’d be fortunate to find one under a log let alone out in the open…
Again, thanks to that aposematic coloration, not much is going to try to tangle with these little toxic tetrapods. Many salamander species utilize refuges or immobility in the presence of potential predators. When predators aren’t around, they’ll move through leaf litter and dodge around under rocks relying on their cryptic coloration to hide them in plain sight. There are certainly exceptions, as some salamander species do have toxins within their skin and showcase warning colors, but these are a few of the characteristics and behaviors that separates salamanders from being newts.
Regardless of their similarities and differences, one thing remains constant: newts and salamanders fill a very important niche within our regional forests, streams and rivers. These creatures are a significant link within the food chain, preying on small invertebrates and compounding their energy into edible protein packets for larger organisms in the ecosystem. So while you are out and about this spring, take a close look at the salamander or newt you find and see if you can tell the difference. Also, give them thanks for all the pesky bugs they eat for you and food they provide for other species!