Wednesday, May 23, 2012

Travel With Crabs: Galapagos

It's time again to

My friends Torrie Behrens and Ben Penzick recently got back from an amazing trip to the Galapagos, and they couldn't wait to share their crab photos with us! (Really, they took a lot of amazing photos of a lot of awesome animals, but we'll just stick to the crabs here.)

Me: When were you in the Galapagos? Where did you actually get to walk around? 

Ben and Torrie: We were in the Galapagos the second week of April, 2012. Prime wet season in the Galapagos so there was a lot of breeding going on from all species and a lot of very small babies running around. We took a small capacity cruise to Baltra, Seymour, Chinese Hat, Bartholomew, Genovesa, Santiago, Rabida, Santa Cruz. Every tour operator's itinerary in the Galapagos is regulated by the park service and most is unseen by tourists. There are designated trails that tourists cannot deviate, luckily most of those trails are close to the shore, allowing maximum crab sightings.

including Sally Lightfoot crabs (Grapsus grapsus)!!!

What did you learn about the crabs you saw?

We learned that the Sally Lightfoot crabs are not endemic to the Galapagos, but can be found throughout the Americas.

crabs, on the rocks

Their coloration is used to attract mates and they're not born with those colors. Their colors vary a lot; I found the most with blue on their chests, and some had very brilliant blues while others were much more pale.

check out this crab's colors! so bright!

When the crabs are born they're a dark rock color which allows the young to blend in with their habitat.

a juvie Grapsus grapsus

They have a lot of predators in the Galapagos including the Lava Heron.

"Lookin' for crabs in all the wrong places." - lava heron

The crabs are not as fearless as most species in the Galapagos, our guide suggested it was because Herons cast a similar shadow of humans, of a different scale, and it makes the crabs scurry away.

They molt their carapaces when they need to grow (their shells do not grow with them) including their eyeballs! Once they molt, they back out of their previous shell and go into hiding because they need to allow time for their shell to harden. At this point, they're soft shell crabs. We also learned that Europeans do not eat soft shell crab!

 Ben with a "t-shirt" or molt

Torrie rockin' some crab fashion

Claws regenerate! (through the molting process: when they shed that hard shell, they can begin to regrow their missing limbs while soft, though it takes a few molts to regenerate fully)

They are able to move so well over rocks because they have two joints that function in different directions allowing full movement of each of their limbs.

mechanics of a molt's legs

The crabs share a habitat with the marine iguanas, and are often climbing right over them, which doesn't bother the iguanas at all.

sharing (space) is caring: it can be fun!

for whatever reason, this iguana cracks me up:
it looks so tiny next to that crab! 

[More crabs with animals!]

sea lion and surf

they even hang out with penguins! (see the red dots?)

What else did you see?

While traveling, we also saw Ghost Crabs that have eyes almost floating above their bodies. They lived in holes in the ground on the beach and would only come out if we were very still and didn't make any vibrations. And we saw freshwater crabs in the Amazon swamp, mangrove crabs along the coast, and various super tiny crabs along mainland Ecuador's coast and hermit crabs!

 a freshwater crab spotted in Ecuador!

Thanks, Ben and Torrie, for letting me share your photos and fun facts!


  1. Thanks Molly for doing such a good job editing, filling in the blanks, and teaching us about the crabs ahead of our vacation! We were able to go to the Galapagos and use the information we learned from your blog to see the crabs in action! (And impress our shipmates!)

    1. You're welcome! I'm so glad you were able to pick up some info here and share more about these beautiful crabs! (And it's always good to impress your fellow travelers!)