Emerald Crabs

[MrSculpin]

I have heard these crabs do well for algae in tanks, but that they are predatory.
But what that means seems vague. Do they hunt fish? Other crabs or what?
I don't want to get one and find it hunts my shrimp or goby.

 

[Myteemouse]

I have a LARGE one in my mixed reef with no problems
BUT, ALL crabs are opportunistic feeders..
Mine has not touched anything in my tank but one the other hand, I know of people that have caught Emeralds eating SPS polyps ...

 

[rainydave]

I have 3 or 4 (I bought 4, but have only seen 3 at the same time in the past month or so) in my BC29. I have never seen evidence of them chowing down on things they shouldn't.

 

[Mopar Reefer]

+1 for the above comments, great for GHA and bubble algae. I have 5 in a mixed reef tank, awesome guys to have in your CUC arsenol!

 

[mjslaugh]

I have never seen an emerald eat corals, but I had three in my bc29 due to two hitchhiking in. The only thing that happened was the bigger of the three caught and killed the other two, it was actually sad he left one of them with only one leg till it starved. I think the rule is one per 30g or something like that as far as the predatory thing goes.

Oh and yes they love the hair algae.

 

[jag3534]

We have one in our bc29 too. He's cool to watch picking at stuff. We thought he was eating our zoo once, but he actually was picking off a dead polyp. We've had him for 4months or so, and haven't noticed him going after anything, but he does love when you feed him, he goes crazy. We have a little clown goby and a little mandarin in that tank too.

 

[cooter181]

I have one in my 29g BC and I have watched him pull hermit crabs out of their shell and eat them, also he tried to eat my nassarus snail the other day. He can't catch the fish but always acts aggresive trying to claw them. Maybe I just have a crazy one. LOL

 

[MrSculpin]

Well my biggest worry was that a crab would get my goby or shrimp. I have a ton of hair algae that has sprouted up since it got warm. Maybe with lots to eat it would behave!