What is my Dwarf Orange Zebra Hermit Crab doing?

Dr. Peter Venkman · Dec 2, 2021

Hey everyone!

So over the past 10 days (or so) I have noticed one of my dwarf zebra hermit crabs climbing on top of some corals and just sitting there. Sometime the crab will sit there in the same place, on top of the same coral for hours without moving. I have never seen this before, and I'm not sure what's going on. None of the corals that it sits on seem to be damaged, so I don't believe the crab is eating them. I also thought maybe the crab is laying eggs within the coral polyps, but I'm not familiar with crabs and their eggs. I have included a pic of the crab sitting on top of my long polyp galaxea. Any help would be great!

KrisReef · Dec 2, 2021

How about a guess ( to get the conversation rolling)

Most of us have no clue about animal behavior but that should not stop anyone from posting a guess at what is happening inside the crabs neural net.

I have to guess that this creature is hoping that the galaxia will capture some drifting morsel which the crab plans to grab and eat before the galaxia can get it into one of its mouths.
Otherwise, it might have climbed up on the mountain to look over the land like Moses?

Edit: You might test my first proposal by target feeding the galaxia and observing the crabs response when food is present. The 2nd isn’t going to be testable imo.

KMCA · Dec 5, 2021

I love the picture. I have no idea why they'd sit on the coral. The hunting strategy theory sounds feasible.
Maybe it's a really weird spot for a molt or to avoid other hermits after its shell?
Or last theory it saw clownfish doing it and decided it wants in on it

G Santana · Dec 5, 2021

I haven't a clue, but that is a great photograph!!!

Dr. Peter Venkman · Dec 5, 2021

Yeah, it's really weird. He love to go up to and chill on the galaxea. That seems to be his favorite coral. I'm also happy that everyone seems to love the pic