10 Facts About Galapagos Marine Iguanas

Galapagos marine iguanas are some seriously cool reptiles. As their name suggests they love a good swim. This makes them distinctly different than their land-based counterparts, the Galapagos land iguana.

If you travel to the Galapagos, I can pretty much guarantee that you will see multiple marine iguanas; they are everywhere – but especially around the water. Read on to learn how these amazing iguanas feed and why they sit around sneezing.

Latin name: Amblyrhynchus cristatus

1. They feed in the water

Marine iguanas feed on algae and seaweed on the rocks under the water. The adults can dive up to 9ft (2.7 m) to rip the algae and seaweed off the rocks with their very small, yet very sharp, teeth.

Younger marine iguanas feed at low tide as they don’t have the strength to dive to the same depths as the adults.

Despite their very long claws and sharp teeth, they are herbivores and use their claws and teeth for eating algae and seaweed, not tearing flesh.

2. They can’t breathe underwater

Marine iguanas can’t breathe underwater because they lack gills (like those on a fish) which are necessary to extract oxygen from water. Instead, they just hold their breath for a really long time.

3. They can hold their breath for a long time

Marine iguanas can hold their breath for a staggering 60 minutes, as proved by Charles Darwin. His shipmate sank a marine iguana over the side of the boat with a weight and then pulled it up an hour later and it was still alive; no doubt more than a little annoyed.

Marine iguanas normally opt for shorter dives of up to 40 minutes, which is extremely impressive – I can barely hold my breath for 30 seconds sitting still.

4. They turn rainbow colors during mating season

Male marine iguanas turn very bright shades of blue, pink, green, and red during mating season to attract females. They turn black again once the mating season is over.

5. The only iguanas that feed in the ocean

Galapagos marine iguanas are the only iguanas in the world that feed in the ocean. They swim by pointing their limbs straight back and twisting their long bodies and tail side to side – like some really funny-looking mermaids.

The raised part from their head to the end of their tail acts like a dorsal fin, making it easier to slide through the water.

6. They play cat and mouse with Galapagos hawks

The Galapagos hawk is the marine iguanas greatest natural predator. They will hunt the adult iguanas, and you wouldn’t think the iguanas have much of a chance.

But these are some feisty little iguanas. Galapagos hawks have even been seen sitting on top of marine iguanas as the iguanas run around trying to shake them off – and the iguana sometimes succeeds.

The iguanas are also extremely fast and can quite easily outrun the hawks if they see them in time. Unfortunately, the young marine iguanas don’t always have the same good results as the adults.

7. They have a symbiotic relationship with mockingbirds

Marine iguanas and mockingbirds have a symbiotic relationship: the mockingbirds let out a distinctive call when there is a Galapagos hawk in the area. The marine iguanas recognize this warning call and flee for cover.

8. They can get pretty big

Adult marine iguanas can reach a length of 5 ft (1.5 m) and a weight of 3 lbs (1.5 kg).

9. Their color matters

The black color of the marine iguana helps it to absorb as much sunlight as possible. These cold-blooded reptiles get quite cold-blooded after a dive into the ocean, they lose a lot of their body heat and may only be around 10°C (50°F).

They need to sunbathe to bring their body temperatures back up, but this slows them down and makes them very vulnerable. It’s a good thing their black color helps them absorb heat as fast as possible!

10. They sneeze. A lot.

Marine iguanas sneeze because they feed in the ocean and consume a lot of salt. This excess salt is unhealthy for them and needs to be expelled; violently and all over their friends.

That’s right, marine iguanas sneeze saltly snot all over themselves and any other iguanas that happen to be close by. This is why most marine iguanas you see have a white encrusted head and neck – all the salty snot has dried on them!

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Little Godzillas

We hope you have enjoyed our 10 amazing facts about marine iguanas! Which fact was your favorite? Have you seen marine iguanas in person? Let us know in the comments below, we love hearing from you! Read about some more amazing animals, like the magnificent frigatebird and Galapagos sea turtle.