Marine iguanas are also, surprise, known as the Galapagos Marine Iguana. These reptiles are unique in the world. They forage at sea for algae. The larger males dive deep and can spend many minutes under water. Females and juveniles eat closer to shore and from the inter-tidal zone. Their noses and teeth are specially adapted to eat close growing algae off of rocks. Burt and I saw a few swim by while we were snorkeling. A lizard at sea. In times of scarce food, caused by current shifts, the iguanas can reabsorb bone and literally shrink in size. last year there was a food shortage and large numbers died. We saw many skeletons and got a good look at their vegetarian teeth. This year the food is abundant and the population is bouncing back. Several island have their own unique subspecies. Old mariners thought the iguanas were ugly. Carol Simon and I think they are sublime. Carol is a herpetologist and the marine iguana is her favorite lizard. When watching sunning marine iguanas you will see them occasionally snort spurts of salty water. They expel excess salt through their noses.