Found this lil guy this morning , I have not seen any corals or fish damaged . Not sure what kind of crab it is but I do not feel comfortable with him in there. Can any Id?
To know for sure look at at the pincers, the ends of it's claws, .. If they are cup like then it maybe a species of algae grazers but if they are pointy then it's a meat eater
yo chris catch that guy, this thread says that Xanthid crab will bust off pieces of your corals and rock to make tunnels. Don't know how true that is but it's like halfway down on this. Seems to be a semi-common hitchhiker, maybe the guy wasn't exaggerating.
I found this guy in my tank a few years ago. I was able to catch him with a net. He was tricky to catch for awhile because I could never find him and then one day I saw him walking on a piece of rock and climb onto the sand and then he buried himself. So I just scooped him out. I put him in my fuge where he lived for 3 years. He just died last summer. Sorry I do not what type of crab he is though. If you do catch him, consider putting him in a sump/fuge. Good luck!