Stow away crab

[the sheik]

I bought some live rock whihc had some crabs hiding in it. I saw one drag a sick damsel into his rock for a meal. I lost another damsel the next day. I don't know if the crab killed the fish or if they died from stress (they died within 3 days from introduction into the tank). Water conditions were OK. The crab is about the size of a nickel and brown with two small pinchers. It's not a hermit crab and I haven't been able to find any pictures of this particular crab. It hasn't harmed the other fish in my tank yet. Does anyone know if this crab may be a danger to my other fish or was he was preying on some sick fish who were almost dead already?

 

[the rock]

the rock says.....
are you hearing snapping sounds or sounds that sound like a rock has fallen against your glass or the glass is cracking especially when the lights are off in the tank?

 

[the sheik]

No I haven't heard any sounds like that. I haven't been able to find any descriptions of crabs that match this guy (I assume that you are thinking of a pistol shrimp?). He's not very active and I rarely see him, except when he's eating my fish.

 

[harris]

try throwing a piece of shrimp or fish near his cave and lure him out to retrieve it. When he comes out get a good look at him and then describe it to us here or at your local fish store.
As far as eating the fis, crabs are scavengers, this is what they do, he is helping along the cycle of your tank.

 

[the rock]

the rock says....
does it look like a normal crab? you know, the kind we eat? or is it long and streamlined and only sticking its face out of the hole and most of the time not able to be seen?

 

[krazzydart]

sounds like a horseshoe crab, they are just a scavenger and only eat dead things...nothing to worry about if it is one. check out the back of it see if it has small points on it!!!!!!

 

[indy1]

Horseshoes are great, mine keeps the sand looking like new

 

[the sheik]

I lured the little guy out of his rock with some food and he has a round, flat body. He's brown and kind of looks like part of the rock. He doesn't seem very active during the day since I never see him (he's most probably nocturnal). Don't think he's a horseshoe.
Thanks everyone.

 

[the rock]

the rock says....
hairy legs? sounds like just your normal crab, watch your corals though

 

[obsessedwithfish]

It sounds like an emerald crab I have a couple of those they are really hard to find on your rock, you could be looking right at them and not notice. I haven't had any problems with mine.
Originally posted by The Sheik:
I bought some live rock whihc had some crabs hiding in it. I saw one drag a sick damsel into his rock for a meal. I lost another damsel the next day. I don't know if the crab killed the fish or if they died from stress (they died within 3 days from introduction into the tank). Water conditions were OK. The crab is about the size of a nickel and brown with two small pinchers. It's not a hermit crab and I haven't been able to find any pictures of this particular crab. It hasn't harmed the other fish in my tank yet. Does anyone know if this crab may be a danger to my other fish or was he was preying on some sick fish who were almost dead already?

 

[halide]

Don't want to worry you had a crab that fit that description and it liked to roll the live rock over to get at stuff underneath.Luckly cought him before he broke the tank.