Common Name: Marine IguanaScientific Name: Amblyrhynchus cristatusType: ReptilesDiet: HerbivoreAverage Life Span In The Wild: 5 to 12 yearsSize: 4 to 5 feetWeight: 1 to 3.3 poundsSize relative to a 6-ft man: IUCN Red List Status: ? Vulnerable LCNTVUENCREWEX Least Concern Extinct Current Population Trend: Unknown
The much-maligned marine iguanas of the Galápagos Islands are so famously homely, even Charles Darwin piled on, describing them as "hideous-looking" and "most disgusting, clumsy lizards."
It's true, they're not pretty, with their wide-set eyes, smashed-in faces, spiky dorsal scales, and knotty, salt-encrusted heads. But what these unusual creatures lack in looks they make up for with their amazing and unique ecological adaptations.
Population
Scientists figure that land-dwelling iguanas from South America must have drifted out to sea millions of years ago on logs or other debris, eventually landing on the Galápagos. From that species emerged marine iguanas, which spread to nearly all the islands of the archipelago. Each island hosts marine iguanas of unique size, shape and color.
Aquatic Adaptations
They look fierce, but are actually gentle herbivores, surviving exclusively on underwater algae and seaweed. Their short, blunt snouts and small, razor-sharp teeth help them scrape the algae off rocks, and their laterally flattened tails let them move crocodile-like through the water. Their claws are long and sharp for clinging to rocks on shore or underwater in heavy currents. They have dark gray coloring to better absorb sunlight after their forays into the frigid Galápagos waters. And they even have special glands that clean their blood of extra salt, which they ingest while feeding.
Threats to Survival
Their population is not well known. They are under constant pressure from non-native predators like rats, feral cats, and dogs, who feed on their eggs and young. They are protected throughout the archipelago and are considered vulnerable to extinction.
Iguanas
Iguanas
Now Playing2:06
Marine Iguanas, the Only Ocean-Swimming Lizards, Explained
Up Next0:44
Swim Alongside a Galápagos Marine Iguana
Now Playing2:02
Florida Is So Cold, Iguanas Are Falling From Trees
Now Playing4:21
Hunting and Eating Invasive Iguanas
Now Playing2:33
World's Deadliest: Hawk Attacks Iguana
Now Playing3:54
Iguana Trouble
Now Playing3:15
Why This Invasive Lizard Is Bad for Puerto Rico
Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.Please be respectful of copyright. Unauthorized use is prohibited.1 / 231 / 23This photo was submitted to Your Shot, our photo community on Instagram. Follow us on Instagram at @natgeoyourshot or visit us at natgeo.com/yourshot for the latest submissions and news about the community.This photo was submitted to Your Shot, our photo community on Instagram. Follow us on Instagram at @natgeoyourshot or visit us at natgeo.com/yourshot for the latest submissions and news about the community.Photograph by Meera Sulaiman, National Geographic Your Shot