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.
They especially do this overnight in order to maintain body heat. Marine iguanas feed on algae that grow on the rocks near the shore, both in the intertidal zones and further out to sea. Adult marine iguanas are capable of making dives for algae that can last for up to one hour.