Heloderma suspectum

The gila monster (Heloderma suspectum) is a venomous lizard native to the arid, hot regions of extreme northern Mexico and the southwestern United States. It is a heavy, slow-moving lizard and is up to 60 cm long. The Gila monster is one of only two known species of venomous lizards, along with its close relative, the beaded or scorpion lizard (Heloderma horridum). Although the Gila monster is venomous, its passive nature means it poses little threat to humans. However, it has earned a fearsome reputation, and is often killed by walkers and house owners.

Description

The Gila monster is the largest lizard native to North America, measuring approximately 14 to 23 inches long. It has a stocky figure with small legs, powerful claws, and a short, thick tail where it stores fat for energy during hibernation or when there is a shortage of food. The Gila monster's skin is rough, with irregular bright pink, yellow, or white markings on black or brown scales. The Gila monster moves exaggeratedly slowly. It does not know how to run and we would try in vain to scare away one of these reptiles. From 500 g to 1 kg in weight, it is a slow-moving, passive reptile.

Their name comes from the fact that several of these have been found near the Gila River in the state of Arizona in the United States.

Habitat

Inhabits arid areas and rocky deserts of North America and dry tropical forests. It lives in burrows that it digs itself, or that it occupies when the owner leaves. The Gila monster generally avoids the extreme heat of the midday sun and is most active during the morning and evening hours. It remains days and weeks without leaving its lair, and when it finally decides to leave its shelter, it does so in rainy weather and almost exclusively at night.

Food

Head of a Gila monster.

The Gila monster is a carnivorous animal that feeds primarily on young rabbits, mice, squirrels, lizards, frogs, insects, birds and bird eggs, turtles, and snakes. It detects the presence of prey by smell, which is highly developed, and also by taste, using its tongue as an effective detector. It is a real eater that devours everything edible it finds.^{[citation needed]} These lizards attack their victims by biting and clinging to them while rolling onto their backs to allow the poison to flow into the wound while continuing to chew to inflict even greater wounds. It gains weight quickly and its tail swells, because it is in that part of its body where its fat reserves accumulate. This unique way of eating allows the Gila monster to fast for a long time without harm. Their low metabolic rate and relatively cool body temperature further reduce their need for regular food intake.

To a large extent, the Gila monster has a specialized physiology that helps it maintain energy levels during its long intervals between feedings. When a Gila monster eats, a modified salivary gland inside its mouth releases a compound called exendin-4, which flows into the lizard's digestive tract and bloodstream. While scientists have yet to confirm the role that exendin-4 plays, it appears that it prepares the Gila's body to receive, process, and store nutrients. In addition, exendin-4 is believed to play a role in the regeneration of the Gila's gut, which atrophies between sporadic feedings to conserve energy.

Playback

Gila's monster.

Animaux venimeux et venins(Phoenicy animals and poisons, 1922).

It is an oviparous animal that lays 3 to 15 eggs, incubating them for a period of 30 to 45 days. The dimension of the egg is 4x6.5 cm and the newborn has a length of 9-12 cm.

Poison

Its jaws are armed, inside the jaw, with a pair of teeth similar to the poisonous hooks of snakes. The venom, used mainly for defense, is secreted through glands located in the lower jaw and flows out through grooves in the teeth.

Conservation status

Near vulnerability (NT). Hunting of this species is prohibited. It is considered a protected species, since its habitat is threatened by urban and agricultural development, and the construction of roads.

Subspecies

There are two subspecies of Gila monster: the reticulate (Heloderma s. suspectum), which is found mainly in the states of Sonora and northern Sinaloa, in Mexico, as well as Arizona, in the United States. Joined; and the banded Gila monster (Heloderma s. cinctum), found in the states of Utah and Nevada, in the United States.

• Heloderma suspectum cinctum
• Heloderma suspectum suspectum

Importance in Type II Diabetes

A peptide analogue of glucagon-like peptide-1 (GLP-1), located in the salivary secretion of this lizard, has been approved for the treatment of patients with type II diabetes. This approval is based on the ability of this agent to increase insulin secretion and therefore improve the hyperglycemia with which the disease occurs in these patients.

Glucagon-like peptide type 1 (GLP-1) is an intestinal factor that is released in response to hyperglycemia resulting from ingestion and that potentiates insulin secretion. It is one of the factors produced in the intestine called incretins, responsible for the incretin effect, known as the difference between the levels of insulin detected after an oral intake of glucose and an intravenous intake of the same quantity. Being the insulin response to oral glucose overload much higher than to intravenous, due to these intestinal factors that enhance the release of insulin.