Gila monster
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? Gila
Monster |
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| Heloderma
suspectum Cope, 1869 |
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The Gila monster (Heloderma suspectum) is a species of lizard that was once thought to be one of only two species of venomous lizards. (The other is the Mexican beaded lizard.) The Gila (pronounced /'hilə/) monster lives in the deserts of the southwestern USA and northwestern Mexico. It is a heavy, slow moving lizard, up to 60 cm (2 feet) long. Its skin has the appearance of beads in the colors black, pink, orange, and yellow, laid down in intricate patterns across the body.
As mentioned above, it was thought to be one of only two venomous lizards, until recent discoveries have shown that iguanas and monitor lizards also produce venom. Unlike a snake, the Gila monster injects venom into its victim not by means of hollow teeth, but through grooves in the teeth of its lower jaw. It produces only small quantities of the neurotoxic venom, which is secreted into the lizard's saliva. By chewing its prey, however, it tries to put as much of the poison into the bloodstream of its victim as possible.
The Gila monster's bite is normally not fatal to humans (there are no reliable reports of fatalities), but it can bite quickly and is known to hold on strongly.
The Gila monster's diet generally consists of small rodents, juvenile birds as well as eggs of both birds and reptiles. They have few natural predators of their own.
The name "Gila monster" refers to the Gila River Basin in Arizona.
In 2005 the Food and Drug Administration of the United States approved a drug for the management of Type 2 diabetes, Byetta (exenatide), a synthetic version of a protein derived from the Gila monster's saliva.
Subspecies
There exist two subspecies.
- Heloderma suspectum cinctum, the banded Gila monster
- Heloderma suspectum suspectum, the reticulate Gila monster
Conservation status
Gila monsters are a protected species under Arizona State law in the United States, and may not be collected, killed, or kept in captivity without a permit in that State. They are currently considered threatened, but not endangered. The main threat to the species is human encroachment. They are listed as threatened under the United States Endangered Species Act, and they appear in Appendix II of CITES.
Morphology of the skeleton
View 3D computed tomographic (CT) animations of the skeleton of adult and juvenile Gila monsters at DigiMorph.org