Emerald Crab Reef Safe?

[WallysWorld]

I have two emerald crabs in my Reefer 170. Both are very active. I put some new frags in my tank on a rack. They wouldn't leave the frags alone! Mostly picking at the frag plugs, but they completely molested a Hammer. I even moved the rack to a location where I didn't think they could get to it, but one figured how to jump from a nearby rock.

What's going on? I thought these were reef safe, am I wrong?

 

[Jason mack]

I have 4 in my 90 g never had any problems , put them in to combat bubble algae , I’ve heard they may try and take small fish when they get big .. but so far mine have been good .... do you dip your corals first before putting them in ..??

My hermit crabs give me more trouble !!!

 

[Bob Weigant]

I stopped using them. Always had frags disappearing.

 

[cloak]

I've never had any luck with them. They didn't eat the bubble algae I had in the tank and then I started noticing what looked like claw marks on some of my sps frags. Back to the LFS it went.

 

[Justfebreezeit]

I had one who was great for about a month but then he started tearing up an Acan head. I scared him away and an hour later he was right back on it. Out he went and never tried again.

 

[WallysWorld]

I have 4 in my 90 g never had any problems , put them in to combat bubble algae , I’ve heard they may try and take small fish when they get big .. but so far mine have been good .... do you dip your corals first before putting them in ..??

My hermit crabs give me more trouble !!!

I bought these from WWC, instructions were to immediately put them in the tank, then dip within 10-24 hours. I did exactly what they instructed me to do, thinking that they ship far more corals in a day than I'll ever have in my tank!

 

[Tyler Bullock]

Mine buggs my hammer and frogspawn so much. I was thinking of taking him out.

 

[redpine42]

I've got 3 they pick algae all day long. Maybe they don't have anything to eat?

 

[WallysWorld]

I've got 3 they pick algae all day long. Maybe they don't have anything to eat?

I do have low algae in my tank....maybe feed these guys some japanese nori?

 

[redpine42]

I do have low algae in my tank....maybe feed these guys some japanese nori?

I read that they like nori. Never seen them eat it though.

 

[Rachelrat03]

I read that they like nori. Never seen them eat it though.

you

caught mine red handed eating nori :) never had a problem with him picking at frags

 

[SPEEDBUMP1204]

I caught mine eating my gsp. I caught him and gave him back to my lfs. I'll never get another one.

 

[Katrina71]

I don't trust them with small fish.

 

[CCK_8814]

I have 2 in my 53gal cube. They’re great, by far the most active and productive members of my CUC. I have a mixed reef, lots of LPS SPS and quite a few rainbow & other btas. Also have 2 clams. One of the crabs got a little brave when I first added the clams and while trying to clean the clams shell got a little too close to the top and the clam actually closed on the crabs claw taking half of it off. If I see him I’ll take a picture. I have acans, a large brain, euphyllia and other corals right on the ground and they leave them alone. When I add a new Frag they do tend to find their way to it rather quickly to pick away at any food that may be on it but I’ve never had any issues with them truly disturbing the coral itself. It’s just like some fish that are “reef safe” with an *, it probably varies from crab to crab. Maybe I just got lucky but I’m very happy with mine. They also do a number on any GHA that shows up in my display. I will also spot feed them some Mysis every few days with a baster to be on the safe side. As far as getting fish, I did have a firefish go missing but I am leaning his disappearance more towards a bta getting him vs the crabs due to a bta moving to where he would sleep. Shortly after then is when I stopped seeing the firefish.

 

[SashimiTurtle]

I have 3 coming for my SCA 90 cube tomorrow. Great at eating algae, will go after what it can catch if it gets starved. You would too... I've never had a problem with corals tho, just a random snail here and there.

 

[Marie7]

I have two emerald crabs in my Reefer 170. Both are very active. I put some new frags in my tank on a rack. They wouldn't leave the frags alone! Mostly picking at the frag plugs, but they completely molested a Hammer. I even moved the rack to a location where I didn't think they could get to it, but one figured how to jump from a nearby rock.

What's going on? I thought these were reef safe, am I wrong?

My own experience..THEY ARE NOT! I ask the reef store and they told me yes they are reef safe, but I did notice the same thing they was picking at my corals specially the hammer head, it also cut the tails of my fishes killing at least 2 I took the fishes to the store and the guy told they have their tails and fins shopped, only thing I thought it was new and I saw lifting their claws every time a fish went by it was the emeral crab, when I took them out from my tank the problem was resolve no more dead fishes, no more tails or fins shopped and no more bother to the corals, so this guys are not reef or fish safe, even when people has some and they don't bother nothing on their tank, but if it do damage to even a single person tank it is not safe...take them out immediately!

 

[Marie7]

I have 2 in my 53gal cube. They’re great, by far the most active and productive members of my CUC. I have a mixed reef, lots of LPS SPS and quite a few rainbow & other btas. Also have 2 clams. One of the crabs got a little brave when I first added the clams and while trying to clean the clams shell got a little too close to the top and the clam actually closed on the crabs claw taking half of it off. If I see him I’ll take a picture. I have acans, a large brain, euphyllia and other corals right on the ground and they leave them alone. When I add a new Frag they do tend to find their way to it rather quickly to pick away at any food that may be on it but I’ve never had any issues with them truly disturbing the coral itself. It’s just like some fish that are “reef safe” with an *, it probably varies from crab to crab. Maybe I just got lucky but I’m very happy with mine. They also do a number on any GHA that shows up in my display. I will also spot feed them some Mysis every few days with a baster to be on the safe side. As far as getting fish, I did have a firefish go missing but I am leaning his disappearance more towards a bta getting him vs the crabs due to a bta moving to where he would sleep. Shortly after then is when I stopped seeing the firefish.

That was the emeral crab, honestly my 2 was tigers not crabs..

 

[Welshheathen]

you

caught mine red handed eating nori :) never had a problem with him picking at frags

Totally this! I’ve had to raise my nori clip higher so my monster emerald wouldn’t take it all. I give him his own piece I feed to him with chopsticks. Trying to save my fingers.

 

[SnailQueen]

Mine was a jerk that was frequently trying to assassinate the royal gramma in the tank. He also consumed a chalice, sponges, and even some xenia. I'd give him nori and pellets, wouldn't touch them. He's also steal food from the rock flower nems. I don't trust them.

 

[choss]

I have one in a 96 gallon tank. It has found a natural cave under a large acan. I have 4 acans with mutiple heads, a frogspawn, a large brain coral, GSP, and a few other LPS. My crab has been a model citizen. I do spot feed his acan home and he eats when I do that but there has not been an issue and I've had him at least 5 months. As long as there is sufficient food to eat I think the crabs are well behaved. But if they get hungry any reef creature may become unsafe.