Rogue emerald crabs

jasonrusso · Dec 27, 2019

I bought 2 emerald crabs about a month or so ago. I was having a gha issue, but that's charging up due to fluco (reef Flux). The crabs are ticking of a lot of corals, and some of my Zoas are disappearing. I caught one picking at my trumpet that looks awful. I caught one on my acan (it closed up but is fine now), and I see them picking inside My Zoa colonies.

Is this normal? I thought they were scavengers? I have a 220 gallon fowler, so these guys will be puffer /eel/tusk food if this is normal or continues.

ccombs · Dec 27, 2019

It has been reported that they do that, but I have only personally seen it when there isn't food for them, or when they get some on accident when going for something else.

AZMSGT · Dec 28, 2019

Yup, I had one and removed it. Little jerk ate $200 in zoas.

Brian Kennedy · Dec 28, 2019

I have a gigantic male living in the sump because he acquired a taste for zoa. Haven’t noticed the females going after coral.

jasonrusso · Dec 28, 2019

Last night one was completely on my RFA. I think they are going into the big tank.

jasonrusso · Dec 28, 2019

Brian Kennedy said:
I have a gigantic male living in the sump because he acquired a taste for zoa. Haven’t noticed the females going after coral.

How do you know the difference?

Brian Kennedy · Dec 28, 2019

The males get bigger and the markings on their abdomens are different.

Brian Kennedy · Dec 28, 2019

There’s a good pic in this thread:

Male vs Female Emerald Crabs

I heard female emerald crabs are smaller and less prone to attacking fish and eating coral. Is this true? What are your guys experience? Thanks and Happy Reefing!

www.reef2reef.com

jasonrusso · Dec 29, 2019

Got one last night. I pulled a leg off the other one last night (those little nails hold on!!). I caught the other one (7 leg) tonight. Both are in the big tank. Let's see if I see them again. My puffer is a good hunter, but he's lazy. If something is too hard he doesn't pursue it.