The slender, long-bodied iguanas of the genus Cteno are the most commonly seen species in the wild; in captivity they are also known as “Spiny Tailed.” Iguanas that are not blood-colored tend to have pale colored bellies, unlike their red and orange counterparts. These lizards also have black dots under their green, leathery skin, and are commonly found hiding under rocks and logs in mountainous areas. Their name, which came from the Spanish word for ‘black tail,’ explains why these snakes look like they have a tail.
The name ‘Spiny Tailed Iguana’ is based on the similarity between the head of the Mexican spiny tail iguana and that of the common boa. Ctenosaura cteno, commonly referred to as the Mexican spiny tail iguana, is actually a medium-sized lizards indigenous to western Mexico. It is smaller than the giant ground sloths. It ranges in size from twenty-one to twenty-five inches in length, with a tail that is between one and two feet in length. The snake’s head, marked dorsolateral to its lower jaw, has a row of short dark colored prominences along its jugal crest.
The holotype of the Spiny Tailed Iguana has a holoptympanic mouth which is ventilated (the tongue may stick out). Its tongue and palate are blackish blue in color, its irides whitish brown, its premolars and molars black, and its caudal ribbons and cauda urs are black with white around them. Its preocular placed, a thin white line separating its eye from the brain, is white inside and black outside. A small yellow throat bone (not visible) is present at the base of its tail. Its head (nose) is rounded, with a long white face, and its large ears, black with white outer margins, give it the appearance of a toad.
At the upper portion of its lower jaw there is a row of teeth like that of the venomous rattlesnake. These teeth are modified to aid in extracting food from soft-bodied insects such as mosquitoes. Its incisors are broad, sharp and bushy. Its preocular sense organs are located in its forehead above its eyes. The Spiny Tailed Iguana has white throat, large crevice mouth, and its large eyes (which, incidentally, are the same color as its coat) give it the appearance of a glowing green snake.
Because of their voracious eating habits, the snakes are considered to be the carnivores on the planet. They can easily take down other small reptiles, including the hare. They are capable of preying upon birds and mammals. Their long, tapered bodies allow them to move silently along the ground. They are fairly nocturnal in their habit of hunting and they are said to live for about fifteen years or more.
In the habitat of the Spiny Tailed Iguana there are around forty known species, thirty of which are known to inhabit the habitats they inhabit. Most live in tropical rain forests, in mud swamps and in humid to dry areas of swampy forests in the southwestern United States. The two subspecies found in this area are the Western Spiny Iguana and the Eastern Spiny Iguana. In addition, there are only two known species in the vicinity of the islands of Baja California and Belize.