The Galápagos marine iguana is unique among all iguanas in the world because it forages in the sea. This unsightly yet intriguing species evolved from land iguanas over five million years ago because of the scarcity of food on the barren islands of the Galápagos. They also morphed into eleven subspecies. Usually they are black and sometimes also have green streaks. Only on Española Island do they display patches of red during mating season. This coloring earned them the nickname Christmas iguanas. This reptile can grow up to five feet.