The Life of Animals | Marine Iguana | The Marine Iguana (Amblyrhynchus cristatus) is an iguana found only on the Galápagos Islands that has the ability, unique among modern lizards, to live and forage in the sea, making it a marine reptile. The Iguana can dive over 30 ft (10 m) into the water. It has spread to all the islands in the archipelago, and is sometimes called the Galapagos Marine Iguana.
In adult males, coloration varies with the season. On land, the marine iguana is rather a clumsy animal, but in the water it is a graceful swimmer. As an ectothermic animal, the marine iguana can spend only a limited time in the cold sea, where it dives for algae. The males assemble large groups of females to mate with, and guard them against other male iguanas.
Marine iguanas have also been found to change their size to adapt to varying food conditions. When food conditions returned to normal, the iguanas returned to their pre-famine size. El Niño effects cause periodic declines in population, with high mortality, and the marine iguana is threatened by predation by exotic species. The marine iguanas have not evolved to combat newer predators. Therefore, cats and dogs both eat the young iguanas and dogs will kill adults due to the iguanas' slow reflex times and tameness.
