Best way to catch Emerald Crab?

[Reefman71]

A complete tank tear down because of three Emerald crabs, I’m pulling my hair out

 

[BighohoReef]

The buggers are challenging. The only time I've caught them eating corals is when one is on its last leg. Your best bet on catching them is to food bait with a jar or tea light cup, I typically leave the cup on a little ledge and let the crab fall in. It is a game of patience I know the frustration trying to catch the little escape artists. Good luck on the hunt!

 

[Reefman71]

The buggers are challenging. The only time I've caught them eating corals is when one is on its last leg. Your best bet on catching them is to food bait with a jar or tea light cup, I typically leave the cup on a little ledge and let the crab fall in. It is a game of patience I know the frustration trying to catch the little escape artists. Good luck on the hunt!

They’re smart, the more I try to catch them the harder it gets, after watching my GMK disappear overnight and seeing them harass the other corals I don’t know if I should be patient or take all my rock out and get it over with.

 

[BighohoReef]

They’re smart, the more I try to catch them the harder it gets, after watching my GMK disappear overnight and seeing them harass the other corals I don’t know if I should be patient or take all my rock out and get it over with.

Sadly sometimes the nuclear option is the best option. It might help if you take the more aggressive one out of the tank, I'm assuming though that its the smartest one as well. If you're like us we have huge rock structures, I'm always fearful of dropping it on places it should be dropped that's obviously a last resort. Like most have said low light, food baiting and cups and tweezers are all good tools for catching. If not you might have to go deadliest catch on those bad boys.

 

[Reefman71]

I appreciate the feedback, I’ll keep this thread posted with my progress. Thank you!

 

[X-37B]

I have had 3 in my 120 for a year and added 4 more.
For 1 year no issues as tank grew.
They have killed 2 acros by stressimg it picking at polyps and flesh.
I have removed some with tweezers and need to get all of them out.
One is killing a softball size tenuis as it sits in it and pickS at it.
They are hard to get out.
Live and learn as I will never have them again.
So far only issue I have had during the 15 months the tank has been up.

 

[Reefman71]

I had to drain my 125. They were eating my Zoanthids. Lost 3 GMK’s and God only knows how many others.

 

[ScubaFish802]

Turn on just the red lights at night and try to grab it before it catches on! lol

 

[Westside Guy]

I also used a long tweezers and caught 3 of them on the top of my rocks after the lights went out for the night. I found the trick was to come from behind them with the tweezers or they will see the tweezers and escape. These emerald crabs can move pretty fast and duck under the rocks.

By the way, they are extremely strong so make sure you have a really strong grip on them if you use a tweezers or they might break loose and escape.

By the way, a few times after my lights went out for the evening I caught them on top my zoa colonies having a full course meal!

 

[Mower55]

Not to say it wouldn’t potentially happen but what makes you think your emerald crab is eating your corals? I have had them in just about all my tanks over the years and have never witnessed that.. They feed mostly on algae and potentially scaveng on dead things. they can aggravate corals by occasionally knocking them over, climbing over them or pick at them during feedings times, mine will also occasionally grab the mantle of my clam but has never really damaged anything.

No, I have one that is eating my soft corals. Trying to get him out as well.

 

[dburnsworth]

I bought an emerald crab to mow down hair algae outbreak in my new tank (was away on vacation). Perfect solution, but once the algae was gone he went after my coral — in spite of my attempts to pacify him with seaweed sheets.

He made a mess of the tank, pulling an acorn frag into the rock work, knocking various corals off the rock, disappearing a brand-new zoa.

It took a lot of patience, but a small jar leaned against the rock work did the trick. Baited it with shrimp for a week or so. Forgot to bait the trap last night, but this morning...success! Guess he just wandered in to see what he could find.

Now I can return to the LFS and put the tank back to rights.

I know this is an older post…but the shrimp in the jar worked perfectly! Thank you! I had a huge ******, coral eating emerald in my display and I fought him last night and sumped him. They are so greedy and can’t resist.

 

[LiveFreeAndReef]

My second crab is still in my tank after removing the really aggressive one ~3 weeks ago. This one is much more timid and well behaved. She molted this weekend and I was able to sex her from the skeleton she left behind. Wondering if maybe the females are better than the males. The one I caught was a male. After molting she's now huge, main body is now about the size of a quarter! Hopefully she remains docile and stays away from things I don't want her to eat!

Females are absolutely better than the males, they stay smaller and show much less aggression. IMO everyone should learn how to sex emerald crabs if they're planning on purchasing them. Leave the males at the store!