Endemic to the Galápagos, these curious reptiles are found in many places across the archipelago, with large colonies on Santa Cruz, Fernandina and Isabela Islands, as well as on Espaῆola and Plaza Sur. Charles Darwin once described them as "imps of darkness".
Dressed to impress
Normally black to absorb the Sun, marine iguanas boast gaudy shades of red, orange, green and turquoise during the mating season (December to March). Males can go without food (algae) for up to two weeks during this period to protect their territory on land.
Marine iguanas spend so much time in the sea that they absorb too much salt. Special glands help them to expel this salt by sneezing it out of their nose.
Survival of the smallest
When food is in short supply marine iguanas can actually shrink their skeleton to adjust for the change in diet. During this period the reptiles can shed up to 20 per cent of their body mass.
When swimming underwater the heart rate of a marine iguana drops by half, allowing it to stay beneath the sea for longer.