Ctenosaura similis, commonly known as the black iguana or black spiny-tailed iguana, is a lizard native to Mexico, Central America, and some Colombian islands in the Caribbean Sea and Pacific Ocean. It has been introduced to the United States in the state of Florida. It is the largest species in the genus Ctenosaura.
Black spiny-tailed iguanas are large lizards native to Mexico and Central America. They have distinctively black, keeled scales on their long tails, which gives them their common name. They have a crest of long spines that extends down the center of the back. Although coloration varies extremely among individuals of the same population, adults usually have a whitish-gray or tan ground color with a series of 4-12 well-defined dark dorsal bands that extend nearly to the ventral scales. Males also develop an orange color around the head and throat during breeding season with highlights of blue and peach on their jowls.
Black spiny-tailed iguanas range from the Isthmus of Tehuantepec (Mexico) to northeastern Nicaragua and western Panama on the respective Atlantic and Pacific coasts. They are commonly found throughout Costa Rica, Honduras and have been reported in Colombia. These iguanas live in dry and moist forests and also occur in open terrains such as savanna, grassland, and shrubland. They can also be found on sandy beaches, in coastal lagoons, marshes, and near urban areas.
Black spiny-tailed iguanas are social and territorial animals that live in colonies. They are active during the day. Although mainly terrestrial, these iguanas are excellent climbers, and prefer rocky areas with plenty of crevices to hide in, rocks to bask on, and nearby trees to climb. They are fast-moving creatures that employ their speed to escape predators but will lash with their tails and bite if cornered.
Black spiny-tailed iguanas are primarily herbivorous (folivores, frugivores). They eat flowers, leaves, stems, and fruit, but will also sometimes prey on smaller animals, eggs, and arthropods. Juveniles tend to be insectivores and become more herbivorous as they get older.
Black spiny-tailed iguanas generally breed in spring. Males show dominance and interest by head bobbing and may chase the female until they can catch her. Within 8 to 10 weeks, the female will dig a nest and lay a clutch of up to 30 eggs. The eggs hatch 90 days later and the hatchlings dig their way out of the sand. The young are typically green in color with brown markings, although all brown hatchlings have been recorded as well.
Black spiny-tailed iguanas are heavily hunted for their meat but they do not appear to be endangered in any of their native range.
The IUCN Red List and other sources don’t provide the number of the Black spiny-tailed iguana total population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
