Salamanders are amphibians, not reptiles. There are over 700 species of salamanders globally, but all are classified as amphibians. Amphibians are ectothermic, vertebrates, lay eggs, and undergo an amazing metamorphosis as they age. Salamanders are spread across nearly every continent and can be found in an incredibly varied range of habitats. But despite this diversity, their amphibian characteristics all remain the same.
Why Salamanders Are Amphibians
Salamanders are cold-blooded, vertebrates, and egg-laying. These three characteristics alone are key to amphibians, but there is also one more distinct trait: metamorphosis. Amphibians are known for undergoing a drastic transformation as they transition from one life stage to another. Most of the time, salamanders hatch from gelatinous eggs laid in water. There are a few species of salamanders that actually lay their eggs on land, but these are a minority.
As a larvae and juveniles, most salamanders initially develop in water. They rely on their gills for breathing as their lungs, legs, and other adult characteristics mature. Once in their adult form, salamanders then transition to a terrestrial or semi-terrestrial environment. However, there are some salamanders that remain entirely or most aquatic. Axolotls are one well-known example of aquatic salamanders (and are one of the best pet aquatic salamanders).
Salamanders and other amphibians have glandular skin, typically a combination of mucous and, less commonly, poison glands. This skin is also permeable, which is how some amphibians use their skin to stay hydrated and breathe. This is called cutaneous respiration and is just one of many unique amphibian adaptations. When you touch a salamander, their skin may feel wet, moist, and even tacky. A dry salamander is typically an unhealthy salamander.
This skin actually presents a potential weak spot for salamanders. Salamanders need to be near water in some form, whether this is a body of water or just an especially damp habitat. Because their skin is so sensitive, a salamander could be hurt because of contaminants in water. A lack of water is equally threatening.
Breaking Down Salamanders vs. Newts
Both salamanders and newts are part of the family Salamandridae. Although there are “true salamanders,” the word ‘salamander’ has turned into a sort of catch-call term that encompass newts as well. (This is why you’ll see newts included in lists of the best pet salamanders.) Therefore, all newts are salamanders even if all salamanders aren’t newts.
The differentiator is that “true salamanders” have ribs or costal grooves along the sides of their bodies, which newts lack. Newts are also generally semi-aquatic and switch between aquatic and terrestrial habitats. They become aquatic during the breeding season and remain on land the rest of the time. However, this is not a completely accurate rule of thumb, since there are semi-aquatic and aquatic “true salamanders” as well.
The Confusion About Salamanders as Amphibians
There is some overlap between amphibians and reptiles that causes animals in one classification to be mistaken for the other. For example, both amphibians and reptiles are cold-blooded (e.g., ectothermic) vertebrates that lay eggs. Salamanders also share many similarities with lizards, which adds to the confusion.
Salamanders have the same physical structure as lizards: a thin body, no external ears, four legs, and a tail. Salamanders and lizards are also both primarily carnivorous, although they can eat plant matter when desperate. Finally, salamanders and lizards can even share habitats, since both prefer areas with ready access to water and higher humidity levels.
But although both amphibians and reptiles are technically herpetofauna, there are many differences between the two types of animals. The more you learn about reptiles and amphibians, the more obvious these differences become. Salamanders lack the key characteristics that classify an animal as a reptile.
And regardless of the similarities, there are more differences between salamanders and lizards. For example, lizards do not undergo a transformation from juvenile to adult, while salamanders do. Additionally, lizards only use their lungs for respiration, while salamanders initially use their gills and can breathe through their skin. And reptiles will either have scales or scutes covering their skin, while salamanders are have neither and are smooth.
Interesting Facts About Salamanders
Salamanders may share the same physical characteristics, but they can have some interesting differences. For example, salamanders can greatly vary in size. The largest salamander can grow up to six feet (the Chinese Giant Salamander) while the smallest is less than in inch (the Arboreal Minute Salamander).
Additionally, salamanders can breathe three different ways. Most salamanders either develop lungs or continue to use their gills. But a small sect of salamanders, known as lungless salamanders, have neither lungs nor gills. Instead, they breathe through their skin and thin membranes in their throat and mouth.
Some of these differences result from habitat. You’ve already learned that newts are salamanders that are terrestrial or semi-terrestrial. But the name for salamanders that are aquatic or semi-aquatic is “sirens.” Sirens usually have both functioning lungs and gills that can be used interchangeably. Their tails are flat, like a fish fin, and help with shoot through water with ease.
Legs are another point of similarity and disparity for salamanders. A salamander’s front legs grow more quickly than their hind legs, but sirens don’t have to worry about this: they only grow their front legs. Some four-legged salamanders are also worry-free, since they can regenerate their limbs.
