Melissa Kaplan's
Herp Care Collection
Last updated January 1, 2014

Spiny-tailed (Black) Iguanas

Ctenosaura spp.

©1995, 2002 Melissa Kaplan


Species and Range
C. acanthura - mainly along Atlantic side of Mexico. Only a few tail whorls; more than one row of granular scales between whorls.

C. similis - from Mexico through Panama; the most frequently imported species. More than one row of scales between tail whorls.

Complete and updated species listing at TIGR Reptile Database...

Found in Mexico, large areas in Central America and islands adjacent to Panama, these 24-36" lizards are great diggers and baskers. They are found around ruins, stone walls, rocky open slopes and branches of large trees along the open borders of the forests.

The Spiny-tailed iguanas tend to be nasty and not tameable like their bigger, green iguana (Iguana iguana) cousins. Juveniles are mostly green, with their adult coloring coming on during their first year. The adult ground color is dark brown-to-gray or black, depending upon the species or subspecies. Most have black mottling on their back. The belly is usually an off- or dirty white. The tail is ringed with specialized spiny scales. While the C. similis has a tall dorsal crest, the other species tend towards very short crests.

Found in wild in groups usually dominated by a major male.


Captive Care

A woodland habitat with substrate suitable for digging: cypress mulch will work well here, but avoid pine or aspen shavings or bark. If mulch is not available, try astroturf-type carpeting. A box of crushed alfalfa hay may be provided for burrowing, or a hide box. A bowl of water should be provided; they may need to have water movement to elicit drinking, at least initially. This may be provided by allowing ice cubes to melt from the screen top of an enclosure into the water bowl

Basking areas up to 100 F; gradient from high 70s to mid 90s during the day, low 70s to low 80s at night. Basking lights should be available 10-12 hours a day.

UVB lighting is essential for proper D3 and calcium metabolism. The unshielded/unfiltered fluorescent tube must be within 12-18" of the lizard. See the document on UV lighting to see a list of UVB producing fluorescents.


According to some sources (Van Devender, in Burghardt and Rand, 1982; Wynn, 1990; Obst, 1988) youngsters in the wild were found to be primarily insectivorous, evolving into more herbivorous habits as adults. They are opportunistic feeders, however, with some study specimens found to steal birds trapped in mist nets. According to some sources (Fitch, Iverson, 1982; Zimmerman and Tracy, 1989), Ctenosauras are completely herbivorous. Most find that their adult spiny iguanas do best on a primarily herbivorous diet, similar to the Uromastyx in captivity (95% plant matter, 5% animal matter).

Start youngsters off on a varied diet of crickets, mealworms and pinks, moving up in prey size as the lizard grows. Plant matter can include the Green Iguana Salad (see my Iguana Care and Socialization document for recipe and food items), plus additional fruits, leaves and flowers. Gut-load invertebrates before feeding out. Plant matter can be offered daily, with animal matter offered in very small amounts with every meal or slightly larger amounts 3-4 times a week.


These oviparous lizards lay clutches of 20-30 eggs in sandy soil. Follow green iguana incubation and diet plans but reduce humidity. Young are 6-7", hatching after 90 days.



Burghardt, GM and Rand, AS. Iguanas Of The World: Their Behavior, Ecology And Captive Care. 1982. Noyes Publications, Park Ridge NJ

Fitch, Henry and Robert Henderson. Ecology and Exploitation of Ctenosaura similis. Univ. Kansas Sci. Bull. 51 (15): 483-500 p.p.

Obst, Fritz et al. The Completely Illustrated Atlas Of Reptiles & Amphibians For The Terrarium 1988. TFH Publishing, Inc.

Wynn, Richard. Lizards In Captivity. 1981. TFH Publishing, Inc.

Zimmerman, Linda and C. Richard Tracy. Interactions between the environment and ectothermy and herbivory in reptiles. 1989. Physiological Zoology 62(2):374-409.


Recommended Reading

Elfstrom, Bruce. Genus Ctenosaura: The Spiny-Tailed Iguana, Reptiles, August 1997.

Gray, Randall. Lizards in the Land of Enchantment--A Visit with Bruce Elfstrom, The Vivarium, Vol 9, #6, 1998.

Emerging Introduction/Invasive Species Problems

Krysko, Kenneth; Wayne F. King, Kevin M. Enge, Anthony Reppas. Distribution of the Introduced Black Spiny-Tailed Iguana (Ctenosaura similis) on the Southwestern Coast of Florida. Florida Scientist 66(2):74-79, 2003.

Townsend, Josiah H., Kenneth L. Krysko, Kevin M. Enge. The Identity of Spiny-tailed Iguanas, Ctenosaura, introduced to Florida, USA. Herpetozoa 16 (1/2):67-72, July 2003.

Related Articles

Overfeeding Iguanas

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