Emerald Crab eating Zoas???

[Surfandturf]

Anyone have problems with emerald crabs eating zoas? Came home yesterday and found one of my emeralds on fire zoas cut in half, presumably by a pincher.

 

[Salty1962]

They are opportunistic feeders. I have heard about folks having issues with them and Emeralds. If in doubt, take it to the sump

 

[jboone82590]

Anyone have problems with emerald crabs eating zoas? Came home yesterday and found one of my emeralds on fire zoas cut in half, presumably by a pincher.

I watched a emerald grab a chunk of acan off and eat it and then the next day watched another one do the same and now there in my fuge eating all my macro lol so i cant win with them

 

[Triggreef]

I maintain about dozen emeralds in my 40g frag tank. Mostly zoas but some other various acan chalice sps. Never an issue with them and I have to feed them nori or whatever to keep p them alive they are knowingly hungry to the point of death if I don't feed them for a couple days I'll see a dead one and know I've neglected them. But none have ever eaten any coral. They are great cleaners and perhaps the only cleaner that can get between polyps to keep them healthy.

Opportunistic they may be. They chase things that move such as disturbed corals. But they are not EATING them. They might cause damage here and there but the shape of their claws are meant for algae. But definitely far and few between, much less damage than you would cause simply moving a frag from one place to another. I have probly more emerald crabs than most reefers since I often order 20 at a time to split between 3 tanks I probly have 80 or so at any given time. They won't even EAT coral if it were the only thing between living or starvation.

 

[cjd]

Emeralds go rogue and eat all types of corals. Once they have a taste for one , consider it gone! I had an emerald eat a war coral in a tank that had plenty of other things to eat. It seems the larger ones can have an appetite for anything . The smaller ones I haven't had too much of a problem. You just have to watch and if one is picking at a coral, he needs to find a new home.

 

[jboone82590]

Will the emeralds be good in the sump? What will they eat?
And i dont mean the fuge?

 

[Triggreef]

Will the emeralds be good in the sump? What will they eat?
And i dont mean the fuge?

They would be fine in the sump especially if its lighted so theres algae growth. Otherwise they'll eat any little morsels that make their way from your tank. They do not eat corals. They might pick at dying corals. They might even pick a little at live ones until they realize its no good. Plenty of war coral and other favias in my tanks not ever touched by emeralds.

 

[Triggreef]

Anyone have problems with emerald crabs eating zoas? Came home yesterday and found one of my emeralds on fire zoas cut in half, presumably by a pincher.

Can we see the zoa where it was eaten?

 

[cjd]

They would be fine in the sump especially if its lighted so theres algae growth. Otherwise they'll eat any little morsels that make their way from your tank. They do not eat corals. They might pick at dying corals. They might even pick a little at live ones until they realize its no good. Plenty of war coral and other favias in my tanks not ever touched by emeralds.

You may have just been on the lucky side. No body is saying that all emerald crabs will devoir all your corals. There is definitely a possibility that one can go rogue and acquire a taste for one . I have had many tanks with emeralds always one of my go to clean up crew guys. I purchased three for my cube and everything was fine for a long time , I noticed one of the crabs get pretty big , I called him Tank. He look like the Incredible Hulk . Well.... he got a taste for my war coral . No, the coral wasn't sick or dying because he would only eat the new growth rings . I watched him peel them off , eat them and leave it be until new growth started to appear. rinse and repeat. So you may have been fortunate not to have emeralds go rogue ,but they are crabs and when an opportunity presents itself they will take it.

 

[mfinn]

I've had a issue with emerald crabs and zoanthids a couple times.

 

[teamlounge]

Yes, they do. As stated above...they are opportunistic feeders. I've seen them chow through zoa's, hammers, frogspawn, etc. Males especially.

 

[Surfandturf]

 

[Surfandturf]

If you look at the pic above, the zoa colony with the orange outside rim is what I am referencing. You might have to zoom in a little but you will see the cut head.

 

[Coastie Reefer]

I've had one pick at a mushroom, never saw it eat it, but just seemed to pinch and pull almost like playing with it. I haven't kept one since. Shame really as I think they're awesome looking little crabs.

 

[Surfandturf]

I've had one pick at a mushroom, never saw it eat it, but just seemed to pinch and pull almost like playing with it. I haven't kept one since. Shame really as I think they're awesome looking little crabs.

Yea its a bummer. This is the second bad experience I have had with the Emerald crab. It has since left the zoas alone. From what I can tell...

 

[feelinfrgy26]

We have also had issues with emerald crabs. Seems to me the small ones don't bother the corals. A couple of mine molten a few times and started on my torch and also my frogspawn, only took about 3 days before one of the heads on my torch was completely devoured. I know it was the crab because I caught one picking at it and had a glowing piece of the torch's flesh in its claw. We moved them to our smaller tank which has less corals and they are doing OK in there but I still have one that's hiding in the big tank that I can't seem to catch. I've had to watch out for a few of my larger hermits too, the bigger they get the more the cause havoc in the tank. They are amazing cleaners though when they are small...

 

[rosshamsandwich]

• any updates?

 

[Siberwulf]

Long time bump, but google got me here. Just watched one pluck a chunk out of a Zoa and eat it. Womp womp. To the sump!

 

[Joesach]

I know this is an old thread, but I added some new zoas to my tank yesterday, went downstairs after dark and saw one of my emerald crabs on the zoas. I checked this morning and it looks like he at an algae covered on that I missed when I removed them from the frag plug. See photo below. So in this one case, it look like the emerald crab cleaned up something I missed.

 

[nycfreshreef]

For everyone who says emeralds don’t eat corals you guys are just lucky … I literally just watched one of my emeralds is a goni polyp , then attempt to eat a cyphastrea polyps but it closed up tight , then proceeded onto a Zoa and ripped an entire skirt out while eating it , the Zoa closed quickly and it stretched opened the polyp with its pinchers and proceeded to eat the entire skirt off in about 15 seconds or so

(not the first time I caught them eating Goni and Zoa specifically)