When this happens, the thyroid gland is no longer under pituitary control. The amount of hormone it produces is dependent on levels of TSI. TSI are the direct cause of hyperthyroidism in Gravesâ disease and various immune system chemicals known as cytokines also contribute to the symptoms that occur in this disorder.
Confidence votes 20. Female Iguanas will lay eggs when they become sexually mature, which is around 1.5 to 2 years old. They do not need to be fertilized to lay so therefore do not need a male Iguana. They need to be healthy before they lay or else there can be very serious problems.
These iguanas, when happy, exhibit a beautiful turquoise blue color. When they are cold or stressed, they are green. The irises of their eyes tend to be a deep reddish-brown, and they generally have black skin surrounding the scales on their bodies, heads, tails and dewlaps.Some may have lots of black in their eyelids.guana Color Variants The following color variants (except the brown) are not generally seen until the iguana is heading into sexual maturity. The hatchlings' deep greens, useful in camouflaging them, begins to lighten, striping or patching diffuse or develop, as they reach one year of age.