emerald crab more of a threat or helper

[tygerfifteen]

I've read mixed feelings on emeralds,
I want to get one for my 68 reef, maybe to try to munch on the hair algae.
will he do damage to any corals?,calupera,cleaner shrimp,snails,fish?
jus wondering , thankx

 

[brianrish]

I love my emeralds. They scoot along all day happily cleaning my live rock. I've never seen them go for anything other than algae and food. But then again I don't have corals.

 

[clarkiiboi]

I too have read/have mixed feelings about these critters. I had one and it ate more off the rocks than I cared for (coraline). I read that the ones with the red/orange joints are ok, with that said I might try again (easy to catch if need be)....HTH
My LFS tried to tell me it ate hair algea too, not real sure on that, but curious.

 

[tygerfifteen]

they eat coraline?? if so forget it lOL

 

[leigh]

i'd been against them for a long time based entirely on hearsay. i finally got tired of removing bubble algae so i got one. within 6 hrs i found it on top of one of my bubble corals attempting to eat the bubbles. i am now against them based entirely on personal experience.
-leigh

 

[overanalyzer]

I have one in my 20 and it is a cool little guy - he just kinda hangs out and does his eating thing. Rarely see him and I have one little piece of hari algea sticking out of the middle of my candy cane coral .... I have some halimeda in my tank and he does not touch it!
If you are thinking to try go with one small one and see what happens!
HTH

 

[jjman101]

I've never had any problems with mine and one of them even eats hair algae every now and then.

 

[broomer5]

I have 5 emerald crabs in my 75.
Two large and three smaller ones.
So far they have behaved well, and are earning their keep.
No problems

 

[leigh]

broomer, or, really anybody, do you all think my emerald was maybe acting with good intentions on my bubble coral? Is there some way I could've mis-interpreted? (He's in my invert tank now and I keep looking at him wondering if I should give him another go in the reef.
-leigh

 

[broomer5]

Hi leigh,
My emeralds are often seen crawling around near the corals. Sometimes they climb right on in, and pick debris.
But they always climb back out, and the coral eventually opens up fully again.
That's just me though - others may have a different story.
Was there any damage to the coral ?

 

[leigh]

the coral was all deflated like--but it reopened within a day to not quite it's full open-ness. it used to open so much it'd actually smoosh up against the glass. it hasn't done that again since. but maybe it just didn't like having a crab sitting on it. in the spirit of forgiveness...he's back in the reef for trial #2...and hopefully he's learned to keep his bootie away from my bubble corals!

 

[kiddow]

i have 3 emermels in my 29, two smaller greens and one that i was first told was a strawberry crab, but doesnt look like any pics i have seen of strawberry crab, so it is a red/emerm. they do eat on my coraline alittle but not enough to make any dent in it and they cleanup all left overs very quickly, they are the funniest things in the tank

 

[justinx]

I had an emerald that only liked to eat corals. He destoyed a xenia colony overnight, then went to work on my pocillopora. He was removed as soon as i could catch him. I will never get another emerald.

 

[sammystingray]

I personally don't think half the folks with emeralds actually have emerald crabs......tons of folks have "emerald" crabs, AKA "green crabs" which aren't even green. There are tons of crabs that look like emeralds, and I often wonder how many don't have the emeralds they think they have.....I have had atleast a couple in atleast one or two of my tanks for around nine years now.....never a single incident with any of them. Emerald crabs have blunt pinchers designed for eating algae. If they get large enough, they can take down a small fish. Don't buy one to take care of a hair algae problem, they don't do a whole lot of damage to a hair algae problem.

 

[justinx]

Originally posted by sammystingray
I personally don't think half the folks with emeralds actually have emerald crabs......tons of folks have "emerald" crabs, AKA "green crabs" which aren't even green. There are tons of crabs that look like emeralds, and I often wonder how many don't have the emeralds they think they have.....I have had atleast a couple in atleast one or two of my tanks for around nine years now.....never a single incident with any of them. Emerald crabs have blunt pinchers designed for eating algae. If they get large enough, they can take down a small fish. Don't buy one to take care of a hair algae problem, they don't do a whole lot of damage to a hair algae problem.
agreed. I question if the crabs that I had (get your mind out of the gutter ) were actually emeralds or not. I know that there are many man y different kinds of crabs out there and it can be difficult to discern between them.
Could anyone post a picture of an ACTUAL emeral crab and a "green crab" and see if we can come up with any significant differencese between these and the "green crabs" often sold as emeralds?

 

[fishman88]

i have 4 in my 29 and they are great i have 1 that is about to molt and the rest just run around the tank all day. i would highly recomend getting them
mike