The Galápagos marine iguana (Amblyrhynchus cristatus) is a species of iguana found only on the Galápagos Islands (Ecuador) that has the ability, unique among modern lizards, to forage in the sea, making it a marine reptile. This iguana feeds almost exclusively on algae and large males dive to find this food source, while females and smaller males feed during low tide in the intertidal zone. They mainly live in colonies on rocky shores where they warm after visiting the relatively cold water or intertidal zone, but can also be seen in marshes, mangrove and beaches.