Five facts about secretive salamanders
- Meghan McMahon
- 2 minutes ago
- 4 min read
What looks like a lizard but isn't? A salamander. Although salamanders share some physical characteristics with lizards, they have plenty of differences. They aren't even closely related.
While lizards are reptiles, salamanders are amphibians, like frogs and toads. Their feet are different too. Salamanders have four toes on their front feet while lizards have five.
The salamander family includes about 600 species across the world. Of these, 20 live in Illinois. They are mostly nocturnal and spend their days hidden away in cool, damp places.
There's a lot of variation among salamanders, and sometimes they go by other names as well. Some salamanders are called mudpuppies, olms or waterdogs. Axolotls, which some people keep as pets, are salamanders. Newts are salamanders that spend most of their time on land, while sirens are salamanders that have lungs and gills and don't usually develop past the larval stage of life.
With so much variation, it's hard to speak about salamanders in generalities. Some have four legs, but some only two. Some lay their eggs on land, some lay their eggs in the water. Even their life cycles can vary.
Read on to learn all about salamanders.
They can regenerate body parts
It might sound like something from a science fiction movie, but most salamanders can regrow some of their body parts if they lose them. This doesn't just apply to their feet and tails. Some salamanders can regenerate brain and eye tissue.
Words to know
Mucus: A slimy substance secreted by mucus membranes for lubrication or protection.
Respirate: To take up oxygen and produce carbon dioxide.
Secrete:Â To form and release a substance.
Torpor: A state of physical and mental inactivity.
Toxin:Â A poisonous substance.
Vernal: Referring to spring.
The axolotl, a critically endangered salamander that lives only in Mexico, can even regenerate its heart and spinal cord. Scientists are studying how salamanders can regenerate body tissue in hopes that it may help humans.
Regrowing a lost limb or tail isn't necessarily a quick process. A salamander that loses its tail — maybe to a predator on the hunt for a meal — may take a year or two to fully regrow it.
While most animals can't regenerate lost body parts, salamanders aren't the only ones with the ability. Many worms can regrow body parts, and crayfish and other arthropods can regrow their claws. Sea stars, which you may know as starfish, can grow back their arms.
They need moisture to survive
Most salamanders have smooth, moist skin, and they need to stay moist to survive. This is why they prefer dark and shady spots, like under rocks and logs or in burrows they dig into the ground. There are even some salamanders that spend their entire lives in damp, dark caves.
Many species of salamanders require a body of water like a pond or a vernal pool to complete their life cycle because they lay their eggs in water. Some kinds of salamanders prefer water so much they never leave it. Axolotls, olms and sirens all spend their full lives in water.
As is common in nature, there is an exception to the rule when it comes to salamanders preferring moist habitats. The Kaiser's spotted newt lives in the Zagros Mountains in Iran, where it is only wet for a few months a year. The newts here emerge and mate during the rainy season in spring and then burrow into the soil and spend the rest of the year underground in a state of torpor.
They 'breathe' through their skin
Most salamanders have lungs, but they don't use them to breathe like we do. Instead, they "breathe" through their skin, which is an important reason why their skin must remain moist. Salamanders absorb oxygen through their skin and then respirate carbon dioxide through their skin as well. Because having moist skin is critical for their respiration, they have glands in their skin that secrete a mucus to keep their skin from drying out.
Salamanders can absorb compounds and other elements besides oxygen through their skin as well. Because of this, they are extremely sensitive to toxins and pollution. They will be among the first species to disappear from an ecosystem if it becomes polluted because they cannot survive in such conditions.
They know how to defend themselves
Many salamanders are an important part of the food web and are a food source for other animals. Because they are commonly hunted, they have defense mechanisms that help them avoid being caught. Their main line of defense is poisonous and foul-tasting skin secretions that make them taste bad to animals that catch them.
Some species have also adapted other means to keeping predators at bay. Dusky salamanders are fast runners and can leap to avoid being caught. The red-backed salamander will coil itself with its head protected, revealing a tail covered in foul secretions. Tiger salamanders can use their tails to flip the dangerous secretions on an attacker's face, and slimy salamanders will smear predators with sticky skin secretions to help them avoid being caught.
Even the bright colors of some salamander species are useful. Predators who see in color will learn to associate the colors of the salamanders with the foul-tasting secretions they emit. Because of this, they will learn to avoid them to prevent becoming sick or to simply avoid a bad-tasting meal.
They are hunters too
All salamanders are carnivores, so hunting is an important part of their survival. Many predators are quick, but salamanders move around pretty slowly. That means they can't easily hunt fast-moving creatures. Instead, they eat a lot of slow-moving animals like worms, slugs, snails and crayfish. Some will also eat small rodents such as mice and shrews.
One thing salamanders have in common with many other carnivores is sharp teeth, which they use to snatch their prey. Some also have long tongues that they can stick out to catch a meal. In some cases, they may lay in wait and then snatch up an unsuspecting animal as it passes by. They will also sometimes slowly creep up on a potential catch and pounce on it.