American Tailed Caecilians: Rhinatrematidae

American tailed caecilians (sih-SILL-yuhns) are medium-sized caecilians with a true, but short, tail. There are a few vertebrae (VER-teh-bree), or the bones that make up the spinal column, behind the cloaca, and these are considered a true tail. The cloaca (kloh-AY-kuh) is the chamber in some animals that holds waste from the kidneys and intestines, holds eggs or sperm about to be released to the outside, holds sperm entering a female's body, and is the passage through which young are born.

Caecilians look like earthworms. A series of rings runs the length of the body starting just behind the head. The rings are inside the body and attached to the vertebrae. American tailed caecilians have three rings per vertebra (VER-teh-bruh, the singular of vertebrae). The skin is folded over the rings, making grooves between the rings. The second and third sets of rings make shallower grooves than the main set.

The mouth of American tailed caecilians opens at the front of the head, and the upper and lower jaws are the same length. The jaws have a dual-action mechanism, like a seesaw. The tentacle openings in these caecilians are next to their eyes. American tailed caecilians are either purplish gray or gray with yellowish stripes along the sides of the body. Adult American tailed caecilians are 8 to 13 inches (20 to 33 centimeters) long.