Geckos and Pygopods: Gekkonidae

Geckos range in size from 0.67 inch (17 millimeters) to 14 inches (35.6 centimeters) in length. The smallest gecko weighs about 0.07 ounce (1.98 grams). The largest gecko, which lives in rainforests, can weigh up to 1.5 pounds (680 grams). While most geckos are brown, gray, or black, a few are yellow, red, blue, orange, or green. They may be plain, or they may have stripes or spots. Colors on the head and neck may be different from the colors on the back. The nocturnal geckos, or those that are active at night, are plainer than the diurnal (die-UR-nuhl) geckos, or those active in the daytime, which tend to have brighter colors.

Geckos usually have flattened bodies and four short limbs, or legs. Each limb has five toes. Some species have claws on each foot. Other types of geckoes have widened toe pads. These toe pads are made to allow the gecko to stick to smooth surfaces. Geckos have large eyes that are open all the time. Except for a few species, the eyes do not have movable eyelids. Instead, the eyes are protected by clear, see-through scales, or thin coatings. Geckos clean these scales regularly with their long tongues. Most geckos are nocturnal. These geckos have vertical pupils (PYU-puhls), meaning that they are positioned straight up and down, in the center of their eyes. Diurnal geckos have round pupils in the center of their eyes. Pupils are parts of the eye that allow light to enter.

Gecko skin is soft and loose and typically covered with granular, or grainy, scales that do not overlap. A few species have smooth skin. Gecko tails come in varied shapes. Many geckos have tails shaped like carrots or turnips. Some have rounder tails that are used to store food.

Pygopods (PIE-go-pods) are also called "snake lizards," limbless lizards," and "flap-footed lizards." They range in length from less than 8 inches (20.3 centimeters) to 2 feet (61 centimeters). Their colors range from pale yellow to dark brown, with or without a pattern of spots or stripes.

Pygopods have a narrow face and an almost snakelike appearance. The snout, or nose area, is pointed. The eyes are always open, protected by transparent, or clear, scales. Most pygopods do not have an outside ear opening. They have no front limbs and only flaplike hind limbs. Their long tails break off easily.