Reef Discussion

Tarik

Member
Jan 9, 2017
1
0
Bad Or Good Crab
Hi.
Im relative new to reef tanks. I found this crab about 2 days ago. Was able to get it out of the tank till i know if he is reef and coral safe. Picture below. Does this crab eat my corals or do damage to my LR ?
Thanks for reactions !
 

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ReeferRob

Solidarité
Oct 22, 2014
2,661
931
Bel Air
I say bad crab. Just remember, ANY crab will, if given a chance, eat something that you deem important. It's what they do, clean up the environment. be it a live or dead fish, shrimp or clam, they'll eat it if they can get their claws on it.
 
Nov 15, 2012
441
107
and possibly eat your CUC. unless you are planning on keeping trigger fish take it back to the LFS. they will most likely feed it to there triggers. if it stays in the tank it will get harder to remove as time goes by. If you have a sump sometimes its OK to let them hang out in there to eat any nasties.
 

Savage Henry

Member
Feb 2, 2015
653
254
It looks like an algae eater to me, but I would err on the side of caution and get rid of it.

I was fortunate in that I had about five crabs of the same type in my fresh liverock and still have two of them (progressively got rid of three) after about 3.5 years and they have remained the same size and only eat algae. In retrospect I should have kept all five.
 

ReeferRob

Solidarité
Oct 22, 2014
2,661
931
Bel Air
You can always watch what it does for a period of time. I only add crabs that I know are algae eater like Emerald crabs and smaller blue leg hermit crabs. Of course I have triggers at the shop so I use them as live food for them, same with mantis shrimps. Quite a spectacle to watch a 30cm titan trigger disassemble one, lol. It's damn well brutal, but that's nature.
 

Savage Henry

Member
Feb 2, 2015
653
254
The only problem I have with my crabs is that my coral beauty backs into them and gets it's tail and anal find bitten off. I think this is just what angels and damsels do when they see something they don't like. I also think it might be the coral beauty trying to get cleaned.
 

Trash

Member
Jan 21, 2013
78
26
Even if it is a grazer, they can get big and be destructive on prized corals etc. there are plenty of other critters to do the cleaning up, get rid of it I say. Not worth the risk. I found my mandarin stuck in a rock with a crab attached to it, I don't know if the mandarin died before the crab got to it but since then, no more crabs for me!