IGUANA

Common iguana (Iguana iguana). any of about 13 species of the lizard family Iguanidae. While the name iguanid encompasses all members of this family, iguana usually refers only to the larger species. The best-known species is the common, or green, iguana (Iguana iguana), which occurs from Mexico southward to Brazil. Males of this species reach a maximum length of over 2 metres (6.6 feet) and 6 kg (13.2 pounds). It is often seen basking in the sun on the branches of trees overhanging water, into which it will plunge if disturbed. The common iguana is green with dark bands that form rings on the tail; females are grayish green and about half the weight of males. Food of the common iguana consists largely of leaves, buds, flowers, and fruits of fig trees (genus Ficus), although many other trees are also fed upon. Whereas this lizard has a well-developed digestive system housing bacteria that ferment plant material, it also eats invertebrates when young and has been known to eat small birds and mammals. During the rainy season, males become territorial, and mating pairs are established. At the end of the rainy season, eggs are fertilized and then laid in clutches of 30 or 50 in the ground during the early dry season. After 70105 days, the 7.6-cm- (3-inch-) long hatchlings emerge. During this time, eggs and young are vulnerable to predators such as coatis and other omnivores. Adult iguanas have been used as food by humans for thousands of years and are threatened by hunting and habitat loss. In rural areas they are a major source of protein. The closely related West Indian iguana (I. delicatissima) lives on several Caribbean islands. Other well-known relatives are the rhinoceros iguana (Cyclura cornuta) of Haiti, the desert iguana (Dipsosaurus dorsalis) of Mexico and the United States, and the marine (Amblyrhynchus cristatus) and land (Conolophus) iguanas of the Galpagos Islands. Common iguana (Iguana iguana). Willis Peterson iguanid any of about 700 species of lizards in more than 50 genera that constitute the family Iguanidae. Iguanids are found throughout the Americas from southern Canada to the tip of South America. The only exceptions are one genus (Brachylophus) in Fiji and other Pacific islands and two genera (Oplurus and Chalarodon) in Madagascar. The family includes the common iguana (Iguana) of the American tropics, the marine iguana (Amblyrhynchus) of the Galapagos Islands, and the common genus Anolis with about 200 species. About 10 genera of iguanids are found in the United States, where they are by far the most conspicuous lizards of the Southwest. Most iguanids have small scales and a large dewlap, or loose fold of skin, situated beneath the head and neck. In many species, a crest on the back and tail is composed of narrow, elongate scales that gradually diminish in size toward the tail. The tongue is short and cannot be thrust out. Iguanids can be regarded as New World analogues of the agamas (family Agamidae) of the Old World, which they closely resemble in structure and body modifications.