Anegada Iguana (Cyclura pinguis) Fact Sheet: Physical Characteristics

Body measurements

*Maximum weight: 8-10 kg (17-22 lb); one of largest species of Cyclura

Weight data from Lazell (2005); Carey (1975) as cited in Lemm and Alberts (2012).

• A large and stout iguana with dusty brown back legs/sides; dorsal spines can be brilliant turquoise blue.
• Spines along back are small, especially in females.
• Juveniles more colorful; body green or blue-green with row of black chevrons.
• Physical traits of C. pinguis are "most generalized" of the iguanas (Lazell 2005)
• Individuals on Guana Island (where they've been introduced) weigh more than those of the same body length on other islands (Lazell 2005)
  • Food limitation may be influencing the Anegada population
  • Other translocated species studied have shown faster growth rates (sexually mature at 2-4 yrs. rather than 6-7 yrs) but not larger size at maturity (Gerber & Alberts 2005)

• Pronounced sexual dimorphism; males larger than females.

• Dentition:
  • Pleurodont (teeth fused to the inner side of the jaw bones; in contrast to acrodont dentition on outer rim of jaw for other lizards)
  • Iguanas in general have strongly compressed teeth; either deep cusps or serrations
  • Teeth adapted for browsing (Auffenberg 1982)
• Markings: (Mitchell 2000b)
  • Juveniles faintly or boldly marked with gray- to- moss green bands separated by gray- to- black chevrons pointing towards the head
  • Adults grayish or brown black above, variable amounts of turquoise on dorsal spines, tail base, limbs, occasionally up onto sides in males
  • Females tend to be not as colorful as the males
• Distinguishing characteristic for most iguanas:(Etheridge 1964)
  • Usually 24 vertebrae before sacrum
  • Usually tail vertebrae have 2 pairs of side flanges (transverse processes)
  • 4 ribs attached to the breastbone (sternum)
• Pores present on skin over femur. (Etheridge 1964)
• Eyes flush bright crimson when agitated; yellow otherwise. (Mitchell 2010)
• Some authors cite clear morphological differences between Cyclura and the genus Iguana (Sites et al 1996) but Lazell (2005) disagrees, saying differences do not consistently divide the two iguana genera
• Can regenerate missing end of a tail. (Perry et al 2007)
• Thermoregulate to maintain high body temperatures in wild - between 30-40 °C (86-104°F)
• Members of the iguanid family, the agamid family (dragon lizards), and the chameleon family all have fleshy tongues and catch their prey with some involvement of the tongue. (Schwenk & Throckmorton 1989)
• Reptiles eyes have four kinds of cones for detecting light wavelengths (compared to three kinds for humans) (Brames 2007)
  • Extra receptor detects UV-A wavelengths; used in species, sexual, and individual recognition, and in foraging and motion perception
  • These UV-A wavelengths unseen by humans
  • Rock iguanas may detect UV light absorbed by femoral gland secretions (Alberts 1989)
    • This ability studied in desert iguanas
    • Pheromone deposits on ground and objects in environment can be located using two modes of sensory input - olfactory and visual
    • Social interactions between iguanas enabled with pheromone detection

This individual has a "mossy" look to it, similar to some other Anegada iguanas with broad stripes on their sides.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Etheridge (1964)
Lazell (2005)
Mitchell (2000b)