iguana

/i gwah"neuh/, n.

1. a large, arboreal lizard, Iguana iguana, native to Central and South America, having stout legs and a crest of spines from neck to tail.

2. any of various related lizards of the genera Iguana, Ctenosaura, Conolophus, and Amblyrhynchus.

[1545-55; < Sp < Arawak iwana]

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Any of about 13 of the larger members of the lizard family Iguanidae.

Best known is the common iguana (Iguana iguana), which ranges from Mexico southward to Brazil. It reaches a maximum length of 6 ft (1.8 m). It lives in trees, especially trees overhanging water, into which it will plunge if disturbed. It is greenish, with brown bands that form regular rings on the tail. It primarily eats tender leaves and fruits but will also eat small birds and crustaceans. Species of the southwestern U.S. and Mexico include the chuckwalla (Sauromalus obesus) and desert iguana (Dipsosaurus dorsalis).

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▪ lizard grouping

 any of eight genera and roughly 30 species of the larger members of the lizard family Iguanidae. The name iguana usually refers only to the members of the subfamily Iguaninae. 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 70–105 days, the 7.6-cm- (3-inch-) long hatchlings emerge. During this time, eggs and young are vulnerable to predators such as coatis (coati) 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.

      Other genera include the West Indian iguana (Cyclura), marine iguana (Amblyrhynchus) of the Galapagos Islands, and the desert iguana (Dipsosaurus) of the southwestern United States and Mexico. All iguanas are egg layers.

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