About this Daily Classroom Special
Critter Corner allows teachers and students to learn and share experiences about organisms that can be kept in the classroom. Critter Corner is maintained by Judith Jones, teacher at East Chapel Hill High School (NC) and Teachers Network web mentor. E-mail Judith. Make sure to visit Judy's other Daily Classroom Special, The Time Travel Interviews with Famous Scientists. 

The Leopard Gecko

We have just acquired a wonderful (big!) leopard gecko in our classroom. Geckos belong to the reptile order of lizards (squamata) and the gecko family (gekkonidae). After taking our gecko's picture, we realized that the title of our school newspaper, The Echo, was in the picture, so we have named it ECHO, the GECKO! 

Scientific Name
Eublepharis macularius
Eu means "true," blephar means "eyelid," and macularius means "spotted."
(Unlike most geckos, leopard geckos do have true movable eyelids. And they are indeed spotted!)

Native Location
Leopard geckos are originally from southern Asia (Afghanistan, Pakistan, western India, Iran). They live in the deserts, grasslands, and rocky steppes, so they are used to warm daily temperatures and are comfortable at room temperatures during the night. But the geckos that you find in the pet stores are the result of captive breeding.

General Physical Description
Leopard geckos come in many color and pattern combinations. Breeders have had a lot of fun creating many variations on the usual theme! Leopard geckos get fairly large - up to 8-10 inches or so. They generally have a yellow background with brownish spots, although the young are sort of striped looking. Their bellies are white. The tail usually has a purple-tinged color and is rather swollen looking. Some of the captive breeding variations include albino, orange, high yellow, striped, jungle, and other unusual patterns. Males and females are hard to tell apart. If you look at the underside of the gecko, the adult males will have an obvious V-shaped row of dark pre-anal pores or bumps. The pre-anal pores of the female are not at all obvious; they are light colored and not at all bumpy. The males also have a wider tail base from the swelling of the hemipenes. Healthy leopard geckos have been known to live to 25 years or so! 

Behavior 
The leopard gecko is nocturnal. It may appear that it is not eating but if you watch the gecko after the sun goes down, you will find that it is hunting crickets and mealworms! Just like its lizard relatives, the gecko has a tail that can break off easily when grabbed (by you or a predator)! The fat tail makes a tasty treat for a predator, since it is a fat storehouse providing the gecko with a food source during lean times. While the predator is filling itself with the tail, the gecko has taken off. The new tail that the gecko will regenerate will be fatter and shorter than the original. The leopard gecko has a wonderfully gentle disposition and is very unlikely to bite. If it does bite, the bite is not very painful and certainly not dangerous. Because of their movable eyelids, leopard geckos will close their eyes when they sleep. They are terrestrial and do not have the toe pads of other geckos. Instead, leopard geckos have claws. They cannot climb out of their habitats as easily! They are carnivorous; a leopard gecko will grab its prey in its strong jaws and then gradually work the food into its mouth.

Classroom Habitat
A simple aquarium is adequate. I use a 20-gallon aquarium without a lid - remember, leopard geckos don't have any toe pads! I have newspaper on the bottom of the aquarium, but you can use other substrates. Astroturf with bound edges or special gecko-safe substrates that pet stores sell will work well. Don't use fine sand - they can ingest the sand and die. Cedar or pine may produce toxins. Potting soil has additives that are problematic, also. Be sure to provide a place to hide since geckos are nocturnal. You can mist this hiding place periodically and this will help the shedding process. The gecko will also like a nice rough rock or chunk of bark to rub against when shedding and to climb upon. Also provide a small shallow dish of water at all times as well as a shallow vessel to keep the food it. Try to keep the temperature at about 85 degrees F during the day and no lower than 65 degrees F at night. You can use reptile heating pads, heat rocks, or a red light bulb over the top (which you will turn off at night). Hot rocks are the least preferred. They do not warm the whole cage and they can sometimes cause burns. 

Food and Feeding Schedule
Mealworms and crickets will make up the majority of the leopard gecko's diet. An occasional wax worm and pinkie mouse make a nice treat. Wax worms are too fatty for a regular diet. Even earthworms can be used once in a while. However, be careful with feeding the leopard gecko any random insect. Lightning bugs, for example, have some sort of toxin that has been known to kill lizards. The leopard gecko should be fed once every day or every other day. The best feeding time is early evening since the gecko is nocturnal. Feed as many crickets or mealworms as the gecko will eat in one feeding. Remove any uneaten food. Crickets hopping around the cage seem to stress the gecko! Calcium or vitamin powder should be provided in a small dish. The leopard gecko should lick the supplement right out of the dish!

Handling Tips
Leopard geckos are very easy to handle and they will be much gentler the more they are handled. Mainly, you need to avoid handling them by the tail since the tail can drop off and will grow back less beautiful. 

Reproduction
I have obviously not had a chance to breed leopard geckos. I only have one! So I will share what I have learned. You can put one male with 3-4 females. Two males together will result in fighting! Leopard geckos will usually mate in January or February and lay the first eggs shortly after that. Females will continue to lay clutches of about two eggs each - up to a dozen clutches in a season. This is because they retain sperm from the initial mating and sort of "dole it out" over a period of time! There should be a closed container in the cage with an opening for the geckos. Keep 2-3 inches of vermiculite inside the container (for egg laying) and mist the vermiculite to keep it damp. The eggs can be removed for incubation if you wish. Just put the eggs in a plastic, shoebox-sized box with moist vermiculite, cover the box and place it into an incubator. Open the box every few days to let a little fresh air in and check for moisture. The eggs take about two months to hatch. Remove hatchlings. They will not eat until after their first shed (usually takes about 5 days). 

Fun Fact 
The gender of leopard gecko hatchlings depends on the temperature! Males come from slightly higher incubation temperatures (85-90). Females come from slightly lower temperatures (80 or so). Females hatched at higher temperatures sometimes are too aggressive for breeding! 

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