Iguana

Iguana (/ɪˈɡwɑːnə/, Spanish: iˈɣwana) is a genus of herbivorous lizards that live in warm places like Mexico, Central America, South America, and the Caribbean. A scientist named J.N. Laurenti first wrote about them in 1768. There are two types: the green iguana, which many people keep as a pet; and the Lesser Antillean iguana, which lives in the Lesser Antilles.

The word "iguana" comes from the Taino people’s word for these lizards, iwana. Iguanas are popular pets, and many have been taken to faraway places such as Ishigaki Island, the Florida Peninsula, Hawaii, Singapore, Thailand, Taiwan, and islands in the Lesser Antilles.

Iguanas are special because they only eat plants and can grow very big, making them interesting reptiles.

Anatomy and physiology

Iguanas are large lizards. They can grow from 1.2 to 2.0 metres long, including their tails. They have special skin folds called a dewlap. They also have rows of special scales along their backs from their necks to their tails. Their scales come in different shapes and colors. This helps them blend into their surroundings.

Iguanas have excellent vision. They can see shapes, colors, and movement far away. This helps them find food and move through forests. They have a special organ on the back of their heads called the parietal eye. This helps them tell the difference between day and night. Iguanas eat only plants. Their strong jaws and special teeth help them chew and digest leaves and other vegetation.

Phylogeny

The green iguana is part of a group of reptiles called iguanians. Scientists study how iguanas are related to other reptiles. Some think iguanians are close to snakes and some lizards. Others think they are close to a skink called the mole skink.

Iguanians, like the green iguana, are special. They can stick out their tongues to catch food, which most reptiles cannot do. They mainly use their eyes to find food and wait quietly to catch it. There are two main kinds of iguanas: the green iguana, found in many places, and the Lesser Antillean iguana, which lives on islands in the Caribbean. Scientists sometimes talk about how to group these iguanas, but they usually recognize several subspecies of the green iguana based on where they live.

Image	Scientific name	Common name	Distribution
	Iguana delicatissima	Lesser Antillean iguana	The Lesser Antilles on Saint Barth, Anguilla, Sint Eustatius, Guadeloupe, Dominica, and Martinique. Historically inhabited all islands between Anguilla and Martinique, except Saba and Montserrat (and perhaps Redonda).
	Iguana iguana	Green iguana	Most of South America, from Colombia east to French Guiana and south to northern Argentina. Also introduced to parts of the Caribbean. If other species formerly considered conspecific are included, ranges north to southern Mexico and the southern Caribbean; specifically Grenada, Aruba, Bonaire, Curaçao, Trinidad and Tobago, St. Lucia, St. Vincent, Saba (island), Montserrat and Útila.

Image	Subspecies	Common name	Distribution
	I. i. insularis	Grenadines horned iguana	St. Vincent and the Grenadines and Grenada
	Iguana iguana melanoderma	Saban black iguana	Saba, Montserrat, and formerly Redonda, but also possibly coastal Venezuela, the Virgin Islands, and Puerto Rico. At least parts of this range may derive from historic introduction.
	I. i. sanctaluciae	Saint Lucia horned iguana	St. Lucia

As food

In some places, iguanas are eaten as food. In Mexico and Central America, people have cooked and eaten iguana meat for a long time. In other areas, like the Dominican Republic and parts of the United States such as Puerto Rico, iguana meat is also eaten. In some Latin American countries like Nicaragua and Colombia, people eat iguana eggs too.

Ecology

Iguanas are important plant-eaters where they live, especially on islands. They help plants grow by eating leaves and flowers. They also help spread seeds by eating fruits. Female iguanas lay many eggs, which give food to other animals. The tunnels they dig for their nests help other animals by making the soil easier to move through. For example, the Lesser Antillean iguana can dig nests as deep as 1.65 metres underground.