Emerald Crab attacks!

[The Saltwater Kid]

Nope, he wasn't getting any food as the Sun Polyps weren't eating at the time, just extended. I originally bought him to take care of a small outbreak of bubble algae which he completely ignored. I know there is a fine line between overfeeding and encouraging nuisance algae to grow and feeding just the right amount to keep everything healthy and happy...finding that happy medium is the key but it's not easy!

 

[Kigs]

I had an emerald crab attack corals to fish. Well, it made an attempt to attack fish but it was too slow. Coral wise, it wanted to chow down some of the LPS and softies in the tank. It found itself in a mantis tank within the hour.

 

[benray4fun]

My emerald killed a mantis..."they both had to go"...

 

[sulp]

Uh Oh....I'm worried now. My new Emerald's carapace was approx. 1" when I got him 3 weeks ago. A perfect size and an efficent part of my clean up crew. I noticed him missing for a whole day an figured he was molting. Boy was I right! He emerged more then double sthe size he was....No exaggeration at all...MORE THEN DOUBLED his size. I have NEVER EVER seen such a thing happen in a single molt. He is now HUGE and a real PIA.

Time to rinse out a snapple bottle, go to the Acme and buy a single shrimp (I love the clerks reaction to this) and get to work.

I'll post pictures after I snag him.

 

[ninjamini]

My emerald killed my sally light foot that I had for over 2 years. One morning I just found him tore up.

 

[Kinetic]

Well my emerald was so big, it ran out of food. I would have to feed it two algae disks a day, or else it would start tearing tissues off my SPS. Eventually I saw it snap and grab one of my gobies and then pulled it back behind the rocks. I couldn't do anything about it, then my other goby dissapeared... then all my AOG frags and more zoos, all my gsp... finally he ate everything he dared and just died.

I'll never get another emerald again.

 

[Misled]

Mine never ate any of his tank mates. One night he decided my green polyped finger leather made a nice umbrella. Crawled up the stalk and latched both pinchers in to hold him in place. Needless to say, the leather was not pleased. I removed him and put him in another place in the tank. Within an hour he was back, latched on. Threw some food in hopinghe would leave for that. He just held on with with one arm and grabbed food as it passed by with the other. Had to go!

 

[Philwd]

I had an emerald get big. 1" claws. Got plenty of food. Would eat mysis as well as any algae. But then it would hover above the randall's goby and tiger pistol burrows waiting for them to come out. Then it started atacking my labouti at night. Fish had in the course of a week 2 chunks taken out of his sides and a very badly torn pec fin. When the lights went out the fish would hide up in the corner of the tank. My wife finally caught the sucker and in the sump he went. No more attacks.

 

[tls]

Good news! the tang is still alive and another night has passed without any attacks! I asked the owner at the LFS about the attack and he said to cut their claws off and they wont attack. I know they will grow back, but i dont want a bunch of amputee crabs running around.

 

[rustybucket145]

umm.... how would he eat without any claws?

 

[tls]

he can feed himself with his feet. like those people on maury povich.

 

[Jeanniee]

I agree with Rich Connely, I have hermits and emeralds and have never had a problem but I am huge believer in regular feedings. Every week I leave a siverside on the bottom for the crabs and they are very happy and nonconfrontational.

 

[jmiller1592]

I agree with TLS. My wife has no hands and she is able to feed herself well with her feet. It took some practice after the accident, but I'm sure the crabs will also adapt.

 

[Grey Reefer]

Check this out wetweb
Some people have trouble and others don't with emerald crabs. My personal experince with them was they did not eat much algae but mostly ate scraps of food that the fish missed. Not very useful critters IMHO, but some people swear by them.

 

[benray4fun]

Well, when I first got my emarald he was small, cute and harmless in appearance. He was supposed to eat the green hair algae that was growing out of control in the tank..."he did this like a machine on steroids." He became an opportunist hunter after the algae was gone,
eating anything he could catch or presented itself..."not picky at all."

I still like the guy, he did what he was supposed to and I would never chuck'm or cut his claws, it's just out of the question for me.
He's very interesting and is still usefull at getting rid of nuisance algaes, excessive coraline, or week dying tank mates..."I'll take the good with the bad." I just won't get another one if he proves excessively costly...

 

[RichConley]

<a href=showthread.php?s=&postid=9225592#post9225592 target=_blank>Originally posted</a> by Philwd
I had an emerald get big. 1" claws. Got plenty of food. Would eat mysis as well as any algae. But then it would hover above the randall's goby and tiger pistol burrows waiting for them to come out. Then it started atacking my labouti at night. Fish had in the course of a week 2 chunks taken out of his sides and a very badly torn pec fin. When the lights went out the fish would hide up in the corner of the tank. My wife finally caught the sucker and in the sump he went. No more attacks.

Are you absolutely sure yours was an Emerald? Theres a couple hundred species of mithrax crabs, and an Emerald's claws aren't made to cut. I can't see how they'd take chunks out of the side of a fish. They simply do not have the anatomy to do it. They have blunt claws.

 

[benray4fun]

<a href=showthread.php?s=&postid=9232634#post9232634 target=_blank>Originally posted</a> by RichConley
Are you absolutely sure yours was an Emerald? Theres a couple hundred species of mithrax crabs, and an Emerald's claws aren't made to cut. I can't see how they'd take chunks out of the side of a fish. They simply do not have the anatomy to do it. They have blunt claws.

Rich, my mithrax takes chunks of coraline out of my live rock. Surely, flesh has got to be easier to take apart, they can be brutal.

 

[techreef]

I have a Ruby Crab in my tank (red colored "emerald" or mithrax crab) I've watched him clipping off polyps from a star coral and an unknown SPS hitchhiking coral on my TBS live rock. I'm also missing one of my two hitchhiking tiger gobies, but that could be due to a 3.5" gorilla crab which I finally caught and removed.

I don't think that it's out of the question that there could either 1) be two separate species of nearly identical mithrax crabs that have wildly differing personalities re: aggression, or 2) just like fish of the same species, each crab has its own personality, and you gets what you gets. There are too many anecdotes of hobbyists watching their emerald crabs preying on fish or corals to simply dismiss it as impossible. On the flip side, there are lots of peaceful emeralds too. It's a big ocean, people. Lots o' possible variety.

 

[thepro]

My emarlad killed a large cleaner shrimp, a sixline wrasse and a clarkii. they are EVIL. get him out.

I put a piece of shrip in a drinking glass, placed it on a 45 degree angle on the bottom of my tank resting against a rock. he crawled in there at night and the glass was too slippery for him to get out. I'm never putting in another crap like that in my tank.