Animal-World > Herptiles > Venomous Lizards > Mexican Beaded Lizard

Mexican Beaded Lizard

Family: Helodermatidae

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Heloderma horridum Photo © Animal-World: Courtesy David Brough

   The size and sheer beauty of the Mexican Beaded Lizard are more than enough to make any intermediate to experienced herp keeper fascinated!

   The amazing Mexican Beaded Lizards are quite unique among the reptiles. It is one of two species of venomous lizards in the family Helodermatidae. Both species are similar in appearance and habits, but its venomous cousin, the Gila Monster Heloderma suspectum, is slightly smaller and more colorful.

   No other lizards have been have been so immersed in myth and mystery as these two. Possibly because of their rather secretive lifestyles, spending a good deal of their time in their burrows, the remoteness of their habitats, as well as being the sole survivors of an ancient group of lizards, the Monstersauria. They have been two of the least understood and least studied of the lizard species, though they have been regularly kept by herp enthusiasts for several decades.

   Mexican Beaded Lizards do not make good “pets”. But for a serious herp enthusiast, their habits and environment requirements make them ideally suited for captivity and visual enjoyment. Despite their size, they don't require a lot of area for activity, and they are relatively easy to keep.

   They are beautiful lizards, and the Mexican Beaded Lizard can be very enjoyable to the experienced herp keeper. They require permits to be owned in many states, and in some states, while the state may not have a law, the city may have regulations regarding these animals.

   Both species of Heloderma are sluggish in habit, but they have a strong, tenacious bite...with a 'bulldog' attitude of not wanting to readily let go.

For more Information on keeping Lizards see:
Guide to a Happy, Healthy Herptile

Distribution:
   Mexican Beaded Lizards are found throughout central and western Mexico from latitude 25 southward to northern Central America. They inhabit thorn scrub and pine forests, as well as tropical forest. They spend a vast majority of their time in their dens or burrows.
   There are four subspecies of Mexican Beaded Lizard; Heloderma h. horridum, Heloderma h. charlesbogerti, Heloderma h. alvarezi, and Heloderma h.exasperatum. Only two if these subspecies, Heloderma h. horridum and Heloderma h.exasperatum are bred in private collections in the United States.

Description:
   The Mexican Beaded Lizards, true to their name, have black “beaded” scales with either a yellow or white pattern to them. They have squat, fat tails that store fat reserves. Their forked tongue is serpentine in nature and flicks in and out to smell, much like a snake.
   They closely resemble the Gila Monster in many ways, except for being larger and darker colored. The venom glands are in their lower jaws, and the venom leeches out from the glands and flows through the grooves in the teeth of the lower jaw and is delivered by a chewing motion. These lizards use venom primarily as a defensive weapon.
   These beautiful lizards can grow to be up to3' (91 cm) in length and weigh around three and a half to five pounds, the females are slightly smaller. The largest males have been known to get to 40” (101 cm) and weigh close to ten pounds. They have a long life span, living 30 plus years.

Care and Feeding:
    In the wild, the Mexican Beaded Lizard eats mostly the eggs of reptiles and birds, and occasionally small animals. In captivity Mexican Beaded lizards will eat commercially available foods, pinkies, mice, and small rats when they are adults. While eggs are a natural food source in the wild, these should be avoided in captivity for a few reasons. The salmonella in eggs can be transferred to your lizard, for one. Also, this food tends to be fattier. This is only acceptable for lizards in the wild, as they must store food reserves in their tail to make it through when there is no food available. In captivity this can lead to obesity.
   To maintain their enclosure, scoop out any fecal matter immediately and replace litter weekly.  Also clean up any spillage of water immediately to prevent the growth of mold.

Environment:
   Adult Mexican Beaded Lizards should be maintained with a minimum of 3 ½ square feet of floor space. Grape vine or other materials may be provided so that they can climb. Substrate can be anything from newspaper to wood shavings, with Aspen shavings being the best. These are easy to clean out and replace and work well with the lizards.
   While they are a desert lizard, they need more humidity than most desert animals. They need a large water bowl that they cannot knock over, preferably large enough for them to soak in if they so desire. If they are allowed to soak daily, the water bowl must be changed daily. Any spillage of water must be cleaned up immediately.
   Because this is a venomous lizard, be sure that the lizard is kept in an enclosure that has a lid to prevent its escape.

Temperature and Lighting requirements:
   These lizards like the temperatures in the low seventies on the cool side of their cage to the high eighties on the warm side. A basking area can be as simple as an elevated rock and placed under the basking light. Heating for the basking area can be provided by a clamp lamp and a bulb with wattage appropriate to the size enclosure the lizard is in.

Handling:
   These lizards should only be handled by trained professionals. A thick pair of leather gloves may be used to offer some protection from these lizards. While many of the adults can be docile, it could take a single person or thing to startle the lizard to incur a bite. These are not tame animals.

NOTE: If you are bitten by a Mexican Beaded Lizard,
seek medical attention immediately!

Breeding/Reproduction:
   Most Mexican Beaded Lizards reach sexual maturity at about 2 1/2 to 3 years. Adult males are larger than females and generally have broader heads and longer necks.
   In the wild, the male would scent out the female in the late spring. In captivity they have been observed to copulate in May and June. The female then lays her eggs in July and August. The incubation period is about 165 to 215 days, with the eggs hatching the following January to February.
   When ready to lay, the female may show some swelling around the rear legs. She should be removed to a private enclose to lay her eggs, as other cage mates will eat them. Provider her with a large nesting box, or put her in an aquarium filled about 3/4 of the way with sphagnum moss for her to burrow down to the bottom of to lay her eggs. She can take up to 24 hours to lay. Vermiculite can be used as an incubation medium, keeping the temperature at about 79° F (26° C).
   Neonate care in the Mexican Beaded Lizard is quite simple. They should be allowed to exit the egg on their own, even if it takes them a few days to do so. They will not eat for their first few days out of the egg, and up to a week. At a week of age, they should be taking pinkie mice. The temperature range for neonate care is from 78 - 88° F (26 - 31 ° C) degrees.

Ailments:
   The biggest problem with Mexican Beaded Lizards is obesity, due to their extremely low metabolism. Take good care to only feed as much as is necessary.

Availability:
   Mexican Beaded Lizards can be purchased from specialty breeders via the internet.

   ** Before attempting to find a breeder or other source for your Mexican Beaded Lizard, you need to check the laws of both your state and your city for the regulations in your area.

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Latest Comments
These are easy animals to maintain and I have yet to have one get sick. The babies are definitely more aggressive. Natural sunlight makes these lizards more aggressive also. They need their nails clipped regularly or your hands will take a beating. If you keep more than one, keep them seperate unless they are the same size (cannibalism) and watch for fights between individuals. mitch 2008-03-05
Pets for Dummies, on the contrary! These critters require respect, proper care and your concentration when being interacted with. I would argue these are pets for educated! mark 2007-09-09
I have enjoyed keeping these heloderms, they are a beautiful and fascinating animal. If you are experienced and give these lizards the respect they deserve, you can enjoy many years with these low maintenance animals. jeff 2007-04-29

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Author: Monica Rearick.
Additional Information: Clarice Brough, CRS
Edited by Animal-World.