Brown crabs-please help quick

[skip]

I'm frustrated! I've done all I know to do and taken alot of advice off this website. I now have about 4" LS and 40pds of LR. I had a pretty sand bed bottom but now it is covered with debre(sp?). I have two brown crabs that I believe were in my LS. One's body is almost as big as my thumbnail. Something is breaking pieces off my LR and now stuff is all on the bottom of the tank. Is it the crabs? I also have 4 red-legged hermits and 3 blue. They are all over everything as well. I noticed last night my 3 feather dusters that were on my live rock and doing well and totally gone! Did my crabs pick them off?

 

[kerry773]

Do these brown crabs have one claw as large or larger then their body? I had one of these little demons appear on my LR three months after the tank was established. The purple coraline algae on the LR near where this guy was hiding started to vanish and the rock looked picked apart. There was also a lot of rubble around where this little guy had wedged himself. He was also very shy...only poking out a claw now and then. Well, he's gone and there was no more distruction of the rock, purple coraline or debris from the LR.

 

[skip]

I don't think so, but I do think one of my so-called hermits might be that way. Can someone please help us as to which crabs are beneficial and which are harmful?

 

[skip]

Just trying to make sure this thread gets seen. I'm counting on you guys!

 

[skip]

There have been 90 people lookat this post and only one to answer who basically had the same question as me Please help.

 

[broomer5]

skip,
Most agree that any crab that you can not positively ID as being beneficial to tank - should be removed.
Many come in as hitchhikers on rock and I suppose live sand.
I've had to remove tannish brown hairy crabs out of my tanks before.
Most are preditors - and will take advantage of anything they can get their gubby claws on to eat.
When in doubt - yank them out.

 

[skip]

Thanks Broomer, I'm going to take them out today. What do you guys do with the stuff you take out? Take back to LFS or flush? And what about red hermits? Are they beneficial or will they pick off small feather dusters? Do dusters ever come back??

 

[oceanjumper]

I never had problems with my hermits. However, I did remove one of my three emerald crabs. It was destructing the LR including mushrooms. I froze it. Of course you can return it to the LFS but then the next reefkeeper will have the same problem (likely).

 

[beth]

I only have a few hermit crabs. Generally, crabs are not the best creatures of a reef system. As for the red hermit, I have only one, and have never had a problem with him.
My emerald crap resently died, but I never had a problem with him either. These crabs eat bubble algae. I used to have a lot of bubble algae, and now I don't have any, so it did its job. Once crabs start to get larger, the will start to tumble LR and could be come a nuiassance to corals, etc.
Leave the red hermit, and see if the LFS will take your other crabs.

 

[fshhub]

if you have a sump or refugium, then you could also put them in there.

 

[dmurphy]

Could the brown crabs be Sally Lightfoots ? .. Do they have a white stripe around the edge of their body ?