Salamander

Salamanders are a fascinating group of amphibians that look similar to small lizards. They have slender bodies, short limbs, and long tails. They belong to a special group called the order Urodela.

These creatures are found most often in eastern North America, especially in the Appalachian Mountains. They also live in parts of Europe, Asia, and North America.

One amazing thing about salamanders is their ability to grow back lost body parts, like limbs and organs, without any scarring! Scientists study salamanders to learn how we might help people heal from injuries or diseases.

Many salamanders have smooth, moist skin that helps them breathe. So, they need to live near water or in very damp places. Some kinds of salamanders, especially newts, have bright colors and produce a strong poison to warn predators away. They usually lay their eggs in water, where their babies grow before changing into adult salamanders.

Etymology

The word salamander comes from Old French salamandre. This word comes from Latin salamandra. The Latin word came from the Greek word σαλαμάνδρα salamándra. In Greek, this word was used to describe the fire salamander. We are not sure where the Greek word came from before that. It might have come from even older languages.

Description

Salamanders are amphibians that look a bit like small lizards. They have slender bodies, short limbs, and tails. Their skin is usually moist and smooth. It can be many colors, from dull to bright. Some salamanders, like newts, have velvety or warty skin.

Salamanders range in size from very small, about as long as a fingertip, to the size of a large fish. They live in many different places, some in water and some on land. Most have four limbs that help them move. Their tails help them balance and swim. Some aquatic salamanders have fewer limbs and look more like eels. Their tails help them move through water or even climb trees!

Feeding and diet

Salamanders are opportunistic predators and will eat almost any organism of a reasonable size. Large species like the Japanese giant salamander (Andrias japonicus) eat crabs, fish, small mammals, and aquatic insects. Smaller salamanders, such as dusky salamanders in the Appalachian Mountains, eat earthworms, flies, beetles, and other small insects.

Salamanders catch their prey in different ways depending on whether they live on land or in water. Land salamanders flick out their sticky tongue to catch food quickly. Water salamanders use their teeth to grab and hold their prey. Some salamanders, like sirenids, eat plants and algae instead of animals.

Defense

Further information: Antipredator adaptations

Salamanders may look slow, but they have ways to stay safe from predators. Their slimy skin makes them hard to catch and can taste bad or even be poisonous. Some salamanders have special glands that shoot toxic fluid to scare away attackers. Others can turn their ribs to poke through their skin as a warning.

Salamanders also use colors to stay safe. Some have bright colors like yellow, orange, or red to show they are poisonous. Others hide with dull colors. If a predator attacks, some salamanders drop their tails to escape, and the tail grows back later.

Distribution and habitat

Salamanders live in many parts of the world, including the Holarctic and Neotropical regions. They are found north of the Mediterranean Basin, the Himalayas, and the Amazon Basin in South America. Some live as far north as Siberia and Labrador.

There are about 760 living species of salamander. Many live in North America, especially in the Appalachian Mountains. A few salamanders can live in salty water, which is unusual for their kind.

Reproduction and development

Salamanders have many interesting ways of having babies. Most species don't use sounds to find mates, and both males and females often look the same. Instead, they use smells and touch to find each other. In some species, males show special behaviors to attract females.

Many salamanders have babies in water, though some land-living types do it on land. In most, the male puts special packages of sperm somewhere, and the female picks them up. This sperm is stored until the female lays her eggs. Some salamanders lay many small eggs in ponds, while others lay fewer, larger eggs in hidden spots in streams or on land. A few keep their eggs inside until they hatch.

Young salamanders usually start life in water as larvae with gills. Over time, they change and lose their gills, developing into adults that live on land. Some salamanders, like the axolotl, keep their larval features even as adults, a process called neoteny. This can happen because of their environment or genetics.

Conservation

Salamanders are facing serious threats that have caused their numbers to drop. One big problem is a disease called chytridiomycosis, which has hurt many amphibian species. Scientists think other factors like deforestation, climate change, and habitat loss are also hurting salamander populations.

Some salamanders, like the Chinese giant salamander, are in very danger because people catch them for food and medicine. There are efforts to help these animals, such as breeding them in captivity and teaching people to protect their habitats. Researchers are also studying ways to help salamanders breed in controlled environments, which could be important for saving endangered species.

Taxonomy

The name Urodela comes from Greek words for "tail" and "visible." It refers to the salamanders' noticeable tails. Scientists sometimes use the words Caudata and Urodela in different ways. This article uses Urodela to describe all salamanders.

Salamanders have ten families grouped into three suborders. A group called Neocaudata sometimes separates certain families from others.

Phylogeny and evolution

Scientists are still figuring out how the three main groups of amphibians are related. These groups are gymnophionans, urodeles, and anurans. Studies show these groups split apart about 360 million years ago. They came from lobe-finned fish during the Devonian period.

Early salamander-like animals lived in the Middle to Late Triassic period, about 250 million years ago. Fossils from that time, like Triassurus, look a bit like today's salamanders but were different in some ways. By the Upper Cretaceous period, most salamander families we know today had probably evolved.

Genome and genetics

Salamanders have very large genomes, ranging from 14 to 120 billion base pairs—much bigger than the human genome, which is about 3.2 billion base pairs long. Two salamander species, Pleurodeles waltl and Ambystoma mexicanum_, have had their genomes fully mapped by scientists.

These large genomes affect many parts of a salamander’s body. They influence the skeleton and circulatory system. One amazing result of their unique genetics is their ability to regrow lost body parts, such as faces, eyes, lungs, and even parts of the spinal cord and brain. This makes them valuable for medical research.

In human society

Myth and legend

Main article: Cultural depictions of salamanders

Salamanders have appeared in many stories and myths. People often linked them to fire because some salamanders live in rotting logs or firewood. When the log burns, the salamander tries to escape, making people think they were made of flame.

Ancient writers like Aristotle and Pliny the Elder told tales about salamanders being so cold that they could put out fire. Some myths even said salamanders could make cloth that wouldn’t burn. These ideas spread across many cultures.

Medical research

Salamanders are important to scientists because they can grow back lost limbs. Researchers study them to learn how new body parts grow, hoping this knowledge can help humans heal injuries or fix damaged organs. Some salamanders, like the axolotls, have been used in these studies. Scientists also found that salamanders can work with tiny green algae, which might help us learn how to treat some human diseases.

Brandy

There have been tales about a special alcohol called salamander brandy from Slovenia. Some people said it had magic effects, but later studies showed these stories were not true.