The marine iguana is not like other iguanas. They have a special ability to live and search for food in the sea. They are the only sea going lizard and exist on the Galapagos Islands, near Ecuador, South America.
Researchers theorize over the origin of the marine iguana. Some think that land and marine iguanas evolved from a common ancestor. Others say they evolved from two separate ancestors from different iguana stock.
In order to be able to feed underwater the marine iguana adapted by developing a pair of salt glands. These glands are located on both sides of the head, under the skin between the nostril and the eye. While eating the iguana will eject a fine spray of highly saline secretion from these glands, to rid itself of the salt.
Marine iguanas can swim better than land iguanas. They hold their legs up to their sides and move their body side to side to swim. They have flattened tails that are perfect for swimming and sharper, longer claws for hanging on to rocks, when be pulled by waves.
The marine iguanas are gray or black, with the exception of during mating season. Males turn shades of red, green or a teal blue.
An adult male has an average length of three feet, while females are half that.
When Charles Darwin visited Galapagos Island in the 19th century and saw thousand of marine iguanas basking in the sun on the rocky shores he was disgusted. He wrote:
The black Lava rocks on the beach are frequented by large (2-3 ft) most disgusting clumsy lizards. They are as black as the porous rock over which they crawl & seek their prey from the sea. I call them ‘imps of darkness.’ They assuredly will become the land they inhabit.
Marine iguanas are herbivorous, they mainly eat marine algae. being they are cold blooded animals, they can only stay in the cold waters for a short time. After they dive for food, they return to the rocks to bask in the sun and raise their body temperatures.
When cold the iguanas are unable to move quickly, making them targets for predators. Dogs, cats, hawks and snakes are a few of the predators on Galapagos Island. Female marine iguanas are at great risk of predators when going to the open nesting grounds.
For most of the year, marine iguanas live in large colonies. However, during breeding season, December through March, males become very territorial.
When courting males will approach the female with his head down. As he gets closer he will begin to bob his head up and down. The female can choose to stay or walk away. If she chooses to stay, mating will soon begin.
About four weeks after mating the female iguanas will leave to lay their eggs in a sandy, soft spot. They will find a spot, dig a nest and lay between one and six eggs. She may guard the nest for several hours or for several days, then she will leave.
The eggs will be in an incubation period for 89 to 120 days. The eggs will then hatch, the baby iguanas will have a look around and go for the nearest cover. Life begins for them.
sources:
www.galapagosonline.com
www.kidcyber.com
wikipedia.org
