Green Iguana

Description:

Green Iguanas possess a row of spines along their backs and along their tails which helps to protect them from predators. Like many other lizards, when grabbed by the tail, the iguana can allow it to break, so it can escape and eventually regenerate a new one. In addition, iguanas have well developed dewlaps which helps regulate their body temperature. This dewlap is used in courtships and territorial displays. They have excellent vision, enabling them to detect shapes and motions at long distances. As Green Iguanas have only a few Rod cells, they have poor vision in low-light conditions. At the same time, they have cells called “double cone cells” that give them sharp color vision and enable them to see ultraviolet wavelengths.This ability is highly useful when basking so the animal can ensure that it absorbs enough sunlight in the forms of UVA and UVB to produce Vitamin D. Green Iguanas have a white photosensory organ on the top of their heads called the parietal eye (also called third eye, pineal eye or pineal gland), in contrast to most other lizards which have lost this primitive feature.This "eye" has only a rudimentary retina and lens and cannot form images, but is sensitive to changes in light and dark and can detect movement. This helps the iguana detect predators stalking it from above. During cold, wet weather, green iguanas prefer to stay on the ground for greater warmth.Green Iguanas are presented with a special problem for osmoregulation; plant matter contains more potassium and as it has less nutritional content per gram, more must be eaten to meet metabolic needs. As Green Iguanas are not capable of creating liquid urine more concentrated than their bodily fluids, like birds they excrete nitrogenous wastes as urate salts through a salt gland. As a result, Green iguanas have developed a lateral nasal gland to supplement renal salt secretion by expelling excess potassium and sodium chloride.

Habitat:

Green Iguanas are diurnal, arboreal, and are often found near water

Notes:

Native to Central, South America, and the Caribbean. Considered as an invasive species introduced from South America; in the United States. Listed on the CITES Appendix II, which means that while they are not an endangered species, "their trade must be controlled so as to not harm the species in the future