Salamanders And Newts: Caudata

Caudata (kaw-DAY-tuh) is the group of animals most people call salamanders but that also includes newts, sirens, hellbenders, olms, mudpuppies, and amphiumas (AM-fee-yoo-muhs). Salamanders are four-legged amphibians that have a long tail and short legs. Amphibians (am-FIB-ee-uhns) are vertebrates (VER-teh-brehts), or animals with a backbone, that have moist, smooth skin; are cold-blooded, meaning their body temperature is the same as the temperature of their surroundings; and, in most instances, have a two-stage life cycle. The word "amphibian" comes from a Greek word that means "having a double life." One of the life stages is a larva (LAR-vuh) that lives in water and has gills, and the other is an adult that lives on land and has lungs. Larvae (LAR-vee, the plural of larva) are animals in an early stage that go through metamorphosis (meh-tuh-MOR-foh-sus), or a change in body form, before becoming adults. Other amphibians are frogs, toads, and caecilians (sih-SILL-yuhns).

The head of a salamander is the same width as or narrower than the trunk. The trunk has twelve to eighteen vertebrae (ver-teh-BREE), which are the bones that make up the spinal column, also called the backbone even though it is made up of more than one bone. The tail of a salamander usually is about the same length as the head and body combined. Most salamanders are 1.5 to 8 inches (4 to 20 centimeters) long, but some can be as long as 5 feet (1.5 meters). Sirens and amphiumas look different from other salamanders in that they have a long, snakelike body, a short tail, and tiny legs.

The moist skin of a salamander contains many glands. Some of these glands make mucus, and some make poison. Most salamanders have camouflage coloring, but some are brightly colored. The brightly colored ones are poisonous or look like the poisonous ones in order to trick predators. Salamander skin is thick and tightly attached to the bone and muscle under it. Salamanders get 90 percent of their oxygen through their skin and also drink through their skin. Salamanders cannot survive if their skin dries out.

Salamanders have a long, fast tongue that contains as many as eleven bones. The tongue shoots from the mouth through the action of specialized muscles. The muscles that bring the tongue back into the mouth are extremely long, being anchored on the animal's hip bones. Salamanders have large eyes they use mainly for finding prey and watching out for predators. Salamanders also have an excellent sense of smell. Although they can hear, salamanders have no outer ears, and sound appears to play little role in their lives.