Introduction to Salamander
Salamander, a tailed amphibian. Salamanders are cold-blooded animals (their temperature changes with that of their surroundings). They have soft skin that is usually moist and must have a humid if not wet environment. Most species are found on land; a few are strictly aquatic. Like other amphibians, salamanders are never found in seawater. Land salamanders are often found under stones and logs. Salamanders are found in North America, Asia, Europe, North Africa, and northern South America.The salamander is a tailed amphibian with soft, moist skin.
Salamanders of most species have four limbs; members of a few species have only two. Most salamanders are from 3 to 8 inches (7.5 to 20 cm) long. The largest species, the giant salamander, grows to about 5 1/2 feet (1.7 m); the smallest is a Mexican species that measures 1 1/2 inches (4 cm). Some species are brightly colored; others are quite dull.
Salamanders are active mainly at night. They feed primarily on insects, spiders, and worms. All salamanders respire to some extent through their skin. Some may also respire through gills, lungs, or the lining of their mouths. Almost all salamanders lay eggs.
Salamanders are often used in laboratory experiments. In some parts of the world, certain species are eaten. Salamanders are sometimes kept as pets. In ancient times it was believed that salamanders could withstand fire and live in flames.
Salamanders are extremely timid creatures. They do tend to startle people, however. It can be scary to move a pile of leaves or a log and suddenly find a salamander living there.
The habit of hiding in such dark places helped salamanders earn their name. In the Middle Ages, people in Europe sometimes would see salamanders scurry out from piles of logs that were set on fire for heating or cooking. They thought the animals were living in the fire itself. So they called them salamanders, from a Greek word for a mythical lizard that lived in fire.
In fact, salamanders much prefer water. They need to keep their skin moist, and they try to keep their eggs moist, too. They like damp, dark places because the insects they like to eat live there. Salamanders have spots on their skin to help them hide from predators.
Like frogs and toads, salamanders are amphibians. Unlike frogs and toads, they keep their tails all their lives.
Salamanders grow up the same way frogs and toads do. They hatch from eggs and emerge as salamander larvae that look a lot like tadpoles. Then they go through metamorphosis. But as adults, they look very different from frogs and toads.
Salamanders look more like lizards than other amphibians. However, they are not dry and scaly as lizards are, and they don’t have claws.
Most salamanders lose their gills, grow lungs, and live on land. But some, such as mudpuppies, hellbenders, and congo eels, never become land dwellers. Many of them keep their gills. Some of them never develop lungs.
Some kinds of salamanders have an amazing adaptation called autotomy (aw TOT uh mee). If something or someone snags the tail of one of these salamanders, the salamander can make the tail fall off. The salamander can then scoot to safety without its snagged tail.
That is not all that a salamander can do. After a salamander loses its tail, it can regenerate (ree JEN uhr ayt), or regrow, a new one. Some salamanders can regenerate legs, too. Some can even regenerate parts of their spinal cord, organs, and eyes.
At first, the new tail or leg or other body part looks pale in comparison to the rest of the salamander. Eventually, the color matches perfectly.
Kinds of Salamanders
There are about 55 genera of salamanders and more than 300 species, grouped into the following 8 families:
Asiatic land salamanders. These are among the most primitive salamanders. They are found only in eastern Asia.
Giant salamanders. Included in this family are the giant salamander (Megalobatrachus japonicus) of Japan and the hellbender (Cryptobranchus alleganiensis) of North America. The hellbender, which inhabits rivers and streams, can reach a length of more than 25 inches (64 cm).
Mole salamanders. Members of this family are found throughout North America. Included in this family are the marbled salamander of the eastern half of the United States and the axolotl. The marbled salamander (Ambystoma opacum) is black with white or grayish markings; it grows to about 5 inches (13 cm).
Fire salamanders and newts. The fire salamanders arc found in Europe and arc of the genus Salamandra.
Amphiumas. There are only two species, found in the southeastern United States. One species (Amphiuma means) grows up to 36 inches (90 cm), the other (A. tridactylum) to about 40 inches (1 m).
Lungless salamanders. It is the largest family, with 180 species. All but two species are found in the Western Hemisphere; the two exceptions are European. Members of this family are from 1 1/2 to 8 1/2 inches (4 to 22 cm) long. Included in this family is the red-backed salamander (Plethodon cinereus).The red salamander has no lungs, but breathes through its skin and mouth tissue.
Olm and mud puppies. The olm (Proteus anguinus), found in Croatia and Montenegro, is a white salamander that reaches a length of about 12 inches (30 cm).
Sirens. The three species in this family are also permanently larval forms. They are the only salamanders without hind limbs. All three are aquatic and are found in the eastern United States.
Salamanders are quiet creatures. They don’t have a mating call. So when a male salamander finds a female he wants to mate with, he does a dance. The male salamander waves his tail back and forth in front of the female, and he sends chemical signals her way. If she likes him, she joins the dance.
The two salamanders walk or swim around each other. Sometimes they bump heads, too. Some kinds of male salamanders also hug the females. Eventually, the male deposits a bundle of sperm nearby and shows the female where it is. She takes the sperm, puts it in her body, and it fertilizes her eggs.
It depends on the type of salamander! Salamanders that live mostly on land just lay their eggs and leave them to their fate. But dusky salamanders and other aquatic salamanders guard their eggs until they hatch.
Usually, the mother aquatic salamander protects the eggs. Among the Japanese giant salamanders, however, the father stays with the eggs.
Not only does the father salamander protect his eggs from predators; he tries to help them grow! He fans them with his tail to create bubbles in the water so the eggs have an oxygen-rich nursery in which to develop.
Like frogs and toads, salamanders must keep an active lookout for predators. They are good at seeing movement. Some can sense movement through their skin. These animals have a good sense of smell, too.
Most salamanders protect themselves by hiding from predators. Some brightly colored salamanders use their coloration to announce that their skin is poisonous. The California slender salamander takes a different approach. It may coil up and spring away.
Terrestrial salamanders, the salamanders that live on land, travel far from home after they grow to adulthood. Some have been known to travel several miles from the pond or stream where they hatched.
During breeding season, these salamanders make the long trip back to water to lay their own eggs. Braving predators, harsh weather, and varied terrain, they make their way home. Using their keen sense of smell, they find the exact spot where they were hatched and continue the family tradition.
Some salamanders make the trip every breeding season. Others make the difficult trip home only every other year. And when some kinds of adult newts return to the water, they stay there for good.
Salamanders make up the order Caudata.