Gila monsters are active all year round

Gila lizard

The Gila lizard (Heloderma suspectum), or also Gila monsterbelongs within the familyHelodermatidae to the genus of the crusty lizards (Heloderma).



The Gila crustacean reaches a total length of 65 cm and an average weight of two kg. Its plump body has a black basic color. They distribute flesh-colored or orange spots over almost the entire surface of the body. Only the front part of the head is predominantly black. In the male, the spots are more strongly colored. The extremities are very short but strongly built and end in sharp claws. The crusty lizard digs their earthworks with them, in which they hide during the day. The large head is clearly separated from the body and is quite flat and wide. The eyes are very small in relation to the head. As with many reptiles, the tongue is forked. The tail is short but of considerable size. It serves as a fat store during hibernation and in periods of hunger. The Gila lizard is able to fast for over a year. It is crepuscular and nocturnal.


In its lower jaw, the Gila crustacean has poison glands that produce a highly effective poison (toxin) to produce. Enzymes such as hyaluronidase and kallikrein as well as serotonin are primarily responsible for the effect. The poison is released through channels from a total of six teeth. Symptoms after a bite include edema at the bite site, drop in blood pressure, nausea and vomiting, and muscle cramps. Treatment is symptomatic. In rare cases, the bite of a lizard can be life-threatening; deaths cannot be ruled out, but very rarely.


The Gila crusty lizard finds its distribution, especially in the Sonoran Desert in the southwest of the USA and in northern Mexico. It prefers dry and rocky habitats such as deserts and semi-deserts with little rainfall. It can be found up to heights of 1,200 to 1,500 meters. She lives exclusively on the ground.


Gila lizard

Eggs from birds and reptiles, smaller vertebrates and invertebrates as well as carrion are on the menu of the Gila crustacean. With the help of Jacobson's organ, she can track down her prey even at night.


The Gila-Krustenechse reaches sexual maturity in the third year of life. After an incubation period of 130 to 150 days, the female lays around 5 to 15 eggs, which are oval in shape. The eggs are laid in self-dug pits. The pits are carefully closed after the eggs have been laid. The female stays close to the nest during the breeding period and defends it against enemies and conspecifics. After an average of 30 days, the young hatch, which already have the compact design of their parents. The Gila crustacean can live up to 20 years in the wild; in captivity, life expectancy can be up to 30 years.


Literature and sources

  • Reichl, Franz-Xaver: Pocket atlas of toxicology, Chap. Animal poisons; Nikol Verlag; 2nd updated edition. ISBN 978-3868200058.

Page Categories: Helodermatidae