Marine Iguanas

Last updated: June 29, 2001

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Marine Iguanas

The Marine Iguana (Amblyrhynchus cristatus) is found on all the islands, and is unique in that it's the only iguana that swims and feeds in the ocean. It eats the algae that grows on the rocks and can dive a couple of meters in the water to chew the stuff off the rocks. During low tide, of course, they just walk around on the exposed algae fields and chew it off.

The water is pretty cold, so the iguanas have to warm up in the sun after each dive (being cold-blooded and all). Our guide had a great line about an iguana that was lying in the sun: "He's not relaxing; he's sunbathing." I doubt that line will work on my wife, but hey, I'll give it a try.

Blow Snot One of the cool things that these iguanas do is to blow salt out of their noses from time to time. Since they're in the ocean all the time, they consume a lot of salt water, and they've got a gland to concentrate it, and then they finally snort it out.

Here's an image snagged from a video of an iguana blowing the salt snot. If you click on the image on the left, you'll get a set of six video frames documenting the wonderful event.

They probably evolved from the common green iguana that is commonly found in Central and South America.

Christmas Swimmer On the left we have a so-called "Christmas Tree" Marine Iguana on Hood Island with beautiful red coloring. The animals on other islands are not so colorful, but this sub-species is pretty amazing. On the right is an iguana doing what they're known for---swimming in the surf.

Dining Immature It seems that the first thing you read in any description of the Marine Iguana is that it eats only the algae in the water. But here on the left is a photo of one dining on a land plant on the first island we visited (North Seymour). He must be "evolving". If you have a relatively fast network connection, click here to see a 3.5 megabyte mpeg of the marine iguana eating something he's not supposed to be eating. On the right is an immature iguana hoping that it won't become the meal of a hawk or snake today.

Mob scene Congaline Finally, here are a couple of iguana mob scenes. Both were taken on Fernandina Island, and I like the photo on the right because of the "conga line" of iguana dancers. Too bad it's back-lit, but I would have had to be up to my hips in the ocean to get a shot from the other direction.