Emerald Crab eating SPS?

goody · Apr 23, 2024

Last night I noticed my emerald Crab hanging out on my homewrecker frag I purchased two weeks ago. I watched it for a few minutes and to my surprise it appeared to be eating the polyps. But I'm not sure if that's really what was happening. Thoughts?? I've never had any issues with emeralds before, but lately I haven't seen the polyps out as much as they were in the attached photo. Luckily I was able to catch it.

Peair · Apr 23, 2024

goody said:
Last night I noticed my emerald Crab hanging out on my homewrecker frag I purchased two weeks ago. I watched it for a few minutes and to my surprise it appeared to be eating the polyps. But I'm not sure if that's really what was happening. Thoughts?? I've never had any issues with emeralds before. Luckily I was able to catch it.

It might be trying to clean it, they looks for pests, algae, or something else, and it does bother the coral sometimes, I think it's best to get it out of there.

Goaway · Apr 23, 2024

Check to see if its a male, i know male emerald are more likely to eat coral.

And since it likes acro polyps, bye bye crab!

goody · Apr 25, 2024

Goaway said:
Check to see if its a male, i know male emerald are more likely to eat coral.

And since it likes acro polyps, bye bye crab!

Removed it and put it in my classroom tank.

Goaway · Apr 25, 2024

goody said:
Removed it and put it in my classroom tank.

Am curious, is coral polyp eater a male?

Jay Hemdal · Apr 25, 2024

goody said:
Last night I noticed my emerald Crab hanging out on my homewrecker frag I purchased two weeks ago. I watched it for a few minutes and to my surprise it appeared to be eating the polyps. But I'm not sure if that's really what was happening. Thoughts?? I've never had any issues with emeralds before, but lately I haven't seen the polyps out as much as they were in the attached photo. Luckily I was able to catch it.

Mithrax crabs are known to eat porites corals in the wild, and have been reported to nibble on other SPS species in captivity.

vetteguy53081 · Apr 25, 2024

goody said:
Last night I noticed my emerald Crab hanging out on my homewrecker frag I purchased two weeks ago. I watched it for a few minutes and to my surprise it appeared to be eating the polyps. But I'm not sure if that's really what was happening. Thoughts?? I've never had any issues with emeralds before, but lately I haven't seen the polyps out as much as they were in the attached photo. Luckily I was able to catch it.

They are not to be trusted especially males (lg clawed). Ive seen too many go after zoa, softies and even polyps on SPS.

feelingfishy · Apr 25, 2024

Had the exact same issue with one of my larger male emeralds. Same issue even down the the same coral, Homewrecker. Tank is a 235 CADE2100s2 with 9 emeralds. I pulled out the problem emerald and put him in the refugium. Since then I feed the tank with sinking formula 2 pellets most nights and this seems to have solved the issue.

Here is a picture of the tank and as you can tell there is like 0 algae so ye that’s a problem for the emeralds.

bbak · Apr 25, 2024

I was suspicious after seeing bite marks on some acros. Then i saw my emerald eating some acropora and montipora in my tank, tried to give it the benefit of the doubt, then it had to get out. Can't trust them. @Battlecorals arbor day sale!