Mythrax/emerald crab

are they mean towards fish, i'm seeing my royal gramma being beat up, either that or my scopus or maroon clown, the gramma likes to sit in the main rock the crab hangs out on

 

All mithrax crabs can be a threat to fish if they're large enough. I would place the blame on the other fish in the tank before blaming the crab though.

 

Ditto what amcarrig said!! Any of the true crabs can grow into a problem. The mythrax crab can get fairly large and pose a problem to fish in its immediate vicinity but it is more likely that you have an aggressive fish (like a maroon clown). The biggest problem with Mythrax that I have read about is that they will start knocking things over because of their size.

I have that problem with a fairly large Neon Blue Hermit that I 've got. He is the bull in the china closet with no ill intent. I had to glue down some corals 'cause he kept moving them around and knocking them over. ;D

Drew

 

John (right?),

Could you post in your sig, your tank set up and such...so we can see that info when you post a question? Thanks!

What I was looking for here was tank size....

Karma, cause you shouldn't have none!!!!!!!!