Ctenosaura pectinata

Species of lizard

Ctenosaura pectinata is a species of moderately large lizard in the family Iguanidae. The species is native to western Mexico. The standardized English name is the western spiny tailed iguana. However, an earlier edition of standardized names applied the name to Ctenosaura pectinata. Confoundedly the name Mexican spiny tailed iguana was applied to Ctenosaura acanthura black spiny tailed iguana, Guerreran spiny tailed Iguana, among other common names. The taxonomic status, relationships, and validity of a number of spiny tailed iguana, particularly Ctenosaura acanthura, C. pectinata, and C. similis have an extensive history of confusion in both scientific and popular literature. The status and relationship of Ctenosaura acanthura and C. pectinata remains unstable (as of 2021) with some limited molecular evidence suggesting Ctenosaura acanthura is a synonym (the same species) of C. pectinata, while others recognize the two as allopathic, morphologically distinct species. The common names Mexican spiny tailed iguana and black spiny tailed iguana (among many other common names) have been loosely and informally applied to all three species at various times.

In Mexico it is found from central Sinaloa to southern Chiapas. It has also been introduced to the United States in the very southern tip of the state of Texas and in the state of Florida.

C. pectinata was first described by German zoologist Arend Friedrich August Wiegmann in 1834. The generic name, Ctenosaura, is derived from two Greek words: ctenos (Κτενός), meaning "comb" (referring to the comblike spines on the lizard's back and tail), and saura (σαύρα), meaning "lizard". These species inhabit lowland (below 1200m elevation) dry forests on both coasts of Mexico and Central America. Additional mitochondrial DNA research is being performed to determine whether additional subspecies may exist. Because of the different human cultures throughout this species distribution, the clades are being evaluated for their impact from humans. Hatchlings are often a bright green color with no body pattern, and darken as they age. Ctenosaura pectinata often (but not always) has an irregular piebald pattern on the head or dorsal areas. Although the tail may be banded with light and dark crossbands, C. pectinata typically lacks a clear or well developed crossband pattern on the body, which is often present in the similar appearing and closely related species Ctenosaura similis and Ctenosaura acanthura. Ctenosaura pectinata varies from gray to a brownish black, with some males exhibiting yellowish colors, and females orange color, on the lateral sides of the body. The young are bright green and unmarked except for black tail bands, present also on adults.

C. pectinata is native to Western Mexico from Sinaloa to Oaxaca. This iguana has been introduced to Brownsville, Texas and South Florida and reproduces in the wild in several feral populations. On the south eastern Florida coast, these iguanas have been found on Key Biscayne, Hialeah, and in Broward County. On the south western Florida coast, it has been reported on Gasparilla Island. It is currently estimated as of December 2007 that there are 12,000 iguanas on this island, descended from a trio of pet lizards released by a resident in the 1970s. They are regarded as a "nuisance animal" on Gasparilla island because the iguanas eat ornamental flowers and shrubs and prey on nesting birds and sea turtle eggs. These iguanas are excellent climbers, and prefer a rocky habitat with plenty of crevices to hide in, rocks to bask on, and nearby trees to climb. This species is listed as "Least Concern" by the IUCN Redlist, but the species is listed on the Mexican Red List NOM 059 2001 as threatened and it is currently illegal to hunt them in Mexico. This protection does not apply to areas in North America where they have been introduced, however. Although hunting, trapping, and killing of these iguanas is illegal throughout Mexico; the Balsas depression along the borders of the states Michoacán and Guerrero is one of the largest illegal hunting and trading areas. The remoteness of the areas and lack of enforcement of the laws is seen as the main reason. A study is being conducted by the Instituto de Biologia, UNAM, to solve the over exploitation problem and to determine if the iguanas can be successfully farmed as a food source similar to the Green Iguana and the closely related Ctenosaura similis.