Distructive crab or commensal?

[meubenfica]

Hi,

I recently noticed two crabs in one of my large Acroporas. They look different than my other commensal crabs in that they have a hairy body. They are small (body id about half an inch). They have small claws like my other "good crabs". However I started noticing some receding tissue on that Acro. That's when I noticed those crabs.

Are they bad?
Could they be the cause of the tissue problem? My other acros seem fine. You can kind of see the tissue recession if you look to the left of the crab.

http://www.reliabull.com/reef/crab.jpg

Should I attempt to catch them?

thanks!!!

[squintypanda]

Hey.. from the picture it looks like a gorilla crab to me (hairy body, pointy claws, and black tips) which are defetnally bad... they're a danger to your livestock and I wouldn't doubt they are indeed causing harm to your acros.... I'm no expert though (only 2 months into the hobby) so you might want to wait till Dr. Ron gets back for an experts opinion.... maybe just go ahead and try and catch em and put them in a species container first? Either way good luck and happy reefing... :)

[rshimek]

Hi,

They appear to be small xanthid crabs (see my column in the December, 2003, issue of [rk]). I would not consider them reef safe, but at the size of the one you have an image, I doubt they could do serious damage. Personally, I would remove them, but it really is up to you.