Emerald Crab picking at SPS

[Rawsreef]

Noticed my acro and my birdsnest were retracted in the middle of the day which is pretty unusual in my experience.

Sure enough the litter booger was behind my acro picking at the polyps of the acro, literally the fuzzy/soft part of the polyps that sway in the current when extended.

After inspecting this behavior for a few mins I could swear i noticed him/her ripping actual tiny pieces off the coral.

I immediately reached in grabbed him and threw him in my DIY sump chaeto fuge.


Was he eating my sps or was he just doing his clean up duties and just so happened t irritate the corals in the process?

 

[jgirardnrg]

Noticed my acro and my birdsnest were retracted in the middle of the day which is pretty unusual in my experience.

Sure enough the litter booger was behind my acro picking at the polyps of the acro, literally the fuzzy/soft part of the polyps that sway in the current when extended.

After inspecting this behavior for a few mins I could swear i noticed him/her ripping actual tiny pieces off the coral.

I immediately reached in grabbed him and threw him in my DIY sump chaeto fuge.


Was he eating my sps or was he just doing his clean up duties and just so happened t irritate the corals in the process?

Could be either... mine were great until they decimated the algae in the tank then started on the pipe organs. I caught them and brought them to my LFS to rehome.

 

[Staghorn]

I’ve got about six Emerald crabs in my tank and probably about 30 different SPS. A lot of which are still tiny frags. I have seen this behavior but still haven’t been able to figure out if they’re actually picking at the coral or not. No corals show any noticeable damage.

 

[Auquanut]

Lots of people have had bad experiences with emeralds. Usually it's more with LPS. I've always kept them and never had a problem. I don't know if it's because of my heavy in - heavy out approach to feeding that's keeping them well fed, or just dumb luck.

 

[Rawsreef]

Thanks for the input !

I think I might try to trade this guy in for something a bit more coral friendly.

Its a shame, cause I actually kind of like the little guy!

Suggestions on a cool replacement??

 

[fcmatt]

Emeralds are not reef safe. Once they get a taste for something they won't stop. Not worth the headache.

 

[Scdell]

Was he eating my sps or was he just doing his clean up duties and just so happened t irritate the corals in the process?

I tend to think this is the correct thinking. I have 4 of them and 99% sps. I see them on the occasional coral with no damage. I think people see them on their acros ad start to freak out right away. I've watched them and watched them. I've seen them picking at what appears to be bare rock. Eating something from it. I personally think they are misunderstood. Lps may be another story, I don't have any so I don't know.

 

[b9sofine]

if tghe coral can recover lerave the crab if n ot pull it out

 

[vetteguy53081]

Not surprised as these guys rarely leave coral alone. Theyre good workers until they get bored and turn to coral. Often they are picking food off and cause damage during the course

 

[sam.veilleux30]

Same thing here, had a few for some months with great results (bubble algae), then they started to go on acros.
Enough to hurt them, munching.
They were worse than my 3 angels

 

[G Santana]

Sometimes you just don't know

 

[Jeffcb]

Mine clean my Goniopora corals. They close all the way closed to the stone and then pop right back out.

 

[Hepatitis]

I got an emerald crab I call Jimmy the Rat because he's a rat *******.

Within an hour of me putting in a stylophora frag, he was picking polyps off. Then when I added an acro frag, he went after it. Ever since then, he's left them alone. Has never touched another coral except a dying zoa frag. And an astraea snail that I guess was dying? Dunno, but he's dead now. It took me forever to figure out, but he was just eating damaged/dying polyps.

He's still a *******, and I still don't really like him, but he's good at hiding.

 

[RedReefer]

No crabs in my tank!

 

[BroccoliFarmer]

Noticed my acro and my birdsnest were retracted in the middle of the day which is pretty unusual in my experience.

Sure enough the litter booger was behind my acro picking at the polyps of the acro, literally the fuzzy/soft part of the polyps that sway in the current when extended.

After inspecting this behavior for a few mins I could swear i noticed him/her ripping actual tiny pieces off the coral.

I immediately reached in grabbed him and threw him in my DIY sump chaeto fuge.


Was he eating my sps or was he just doing his clean up duties and just so happened t irritate the corals in the process?

I believe there is one and only one resolution to this: shecrab soup

 

[Jay Hemdal Verified Community Expert]

Noticed my acro and my birdsnest were retracted in the middle of the day which is pretty unusual in my experience.

Sure enough the litter booger was behind my acro picking at the polyps of the acro, literally the fuzzy/soft part of the polyps that sway in the current when extended.

After inspecting this behavior for a few mins I could swear i noticed him/her ripping actual tiny pieces off the coral.

I immediately reached in grabbed him and threw him in my DIY sump chaeto fuge.


Was he eating my sps or was he just doing his clean up duties and just so happened t irritate the corals in the process?

Emerald crabs are known to eat Porites coral in nature, so eating other SPS in captivity is probable.
Jay

 

[Chrisv.]

Get rid of him!

 

[Jay Hemdal Verified Community Expert]

Emerald crabs are known to eat Porites coral in nature, so eating other SPS in captivity is probable.
Jay

The reference for this is for the species Mithrax sculptus, reported to eat up to 10 Porites polyps per minute. Description in Patrick Colin's Caribbean Reef Invertebrates and Plants. There may be other species of Mithrax in the hobby though.....

Jay