What is the difference between salamanders and newts

Salamanders vary in size with the smallest being the one-inch long minute salamander. On the other end of the spectrum is the largest of all amphibians, the six-foot-long Chinese giant salamander. Some species of salamanders have evolved to adapt to aquatic life and, therefore, do not develop hind legs. Other species which live on trees in their adulthood have webbed feet which have excellent suction capabilities.

Newts are amphibians of the Pleurodelinae subfamily. Like all amphibians, newts spend the early stages of their lives in water after hatching as larvae. Newt larvae feed on small invertebrates and other larvae and take a couple of months to undergo metamorphosis and transform into adults. Upon reaching adulthood, the newts, which are also known as efts, will take on a terrestrial lifestyle and only return to the water to breed.

To facilitate life on land, adult newts develop lungs to replace their external gills which they absorb. Due to their docile temperament, newts are a favorite pet in many households in North America and Europe. Physical appearance: newts have brightly-colored skin which is an indication of the presence of toxins on their skins.

While salamanders and newts may initially appear similar and it can be confusing to tell them apart, they are actually incredibly different. Salamander diversity is complex — salamanders are split into several families in the order Urodela, or clade Caudata. The family Salamandridae contains true salamanders and newts, with newts classified into the subfamily Pleurodelinae.

Typical of amphibians, both salamanders and newts start their life cycle with an aquatic larval stage. Newts then generally develop into semi-aquatic or aquatic adults, while salamanders are often found living in moist terrestrial environments during the adult stage of their lives.

There are approximately species of salamanders and 60 species of newts that have been identified, with scientists estimated there are many, many more yet to be discovered. Just a few examples of the complicated diversity amongst this order include the eastern newts, Notophthalmus viridescens which have 3 stages in their life cycle: an aquatic larval stage, a juvenile terrestrial stage known as efts , and then back to an aquatic stage as an adult.

There are also species of salamanders that are aquatic for their entire lives, such as the eastern hellbender Cryptobranchus alleganiensis and the mudpuppy Necturus maculosus which does not even undergo metamorphosis.

Salamanders and newts can be differentiated by a few physical characteristics. Newts generally have webbed feet and a tail shaped like a paddle, which makes them well adapted for life spent mostly in the water.

Newts also have rougher skin than salamanders, and some species are even dry or warty in appearance. Finally, newts exhibit more sexual dimorphism than salamanders.

In some species males grow a prominent crest for display, such as in the European great crested newt Triturus cristatus , which looks rather like a tiny dragon. Salamanders often have longer tails and feet with developed digits for walking, climbing, and digging. Salamanders are more often confused with lizards due to their appearance, however they completely lack the scales or claws of lizards.

Depending on the species, either adult salamanders or newts may have developed lungs, gills, or both. The lungless salamanders in the family Plethodontidae lack lungs and breathe air entirely through their moistened skin. Salamanders and newts vary in size — as there are many more species of salamanders than newts, size variation in salamanders is greater. The vast majority of salamanders are generally around 6 cm in length.

The smallest salamander, a pygmy salamander Thorius arboreus of Mexico reaches only 0. Giant Salamanders in Asia can grow to impressive sizes. The largest recorded Chinese Giant Salamander , Andrias davidianus, was 5. The eastern red-spotted newt is found in eastern North America in ponds, lakes and marshes. Many newts are active during the day while others are active during the night.

All of them spend most of their time hunting for food or lounging in a cool area in the shade. Their mating ritual is particularly interesting. When mating season comes, the male secretes a strong pheromone to attract a female. Then, it does a little dance by swinging its tail in the air. The pheromone works so well that when a male isn't around, females will try to mate with each other, according to a study by the Free University of Brussels.

Newts can regenerate fully functional limbs , organs and tissues, including heart muscle, components of its nervous system and the lens of its eye, according to an article in the journal Nature. Researcher hope the ability is based on a common genetic trait and is found, even in latent form, in all animals. Studies indicate, however, it may not be that simple because of the enormous size of the newt genome, which is 10 times larger than the human genome. Many newts rely on their skin color — green, black or brown — to camouflage them and escape the notice of predators.

Others are marked with bright warning colors to indicate they are toxic and would not make a good meal, according to Caudata Culture. These newts secrete a mucus that is quite toxic. A study published in the journal Toxicon found that at least 10 species had substances called tarichatoxin and tetrodotoxin. Tetrodotoxin, or TTX, is the most poisonous nonprotein substance known to scientists and is similar to that found in pufferfish, according to Caudata Culture.

It is a powerful neurotoxin that block signals from the nervous system to the muscles, so for example, it blocks the signals from your brain that tell your heart to beat. The study found that the skin of a rough-skinned newt is poisonous enough to potentially kill 25, mice.

The study also cited a case that involved a man in Oregon who swallowed a newt on a dare he had been drinking heavily. After a few minutes, his lips began to tingle. Over the next two hours he began to feel numb and weak and then experienced cardiopulmonary arrest. Later that day, he died, despite hospital treatment. In another study, published in in the journal Copeia, newt toxin entered a puncture wound on a scientist's index finger, and he suffered 30 minutes of numbness up the arm into the shoulder, and some accompanying nausea and light-headedness.