Need advice on nasty hitchhikers

[Shawner9ster]

I have many problematic inverts in my tank that came free of charge on/in liverock whan i started my 75g over a year ago. They are now of a size that they now prey on hermitcrabs, snails, and now starting on mushrooms and polyps. I know the culprits for the snails and hermits are a couple of mantis shrimp as i have seen them. I also know I have three unidentified crabs wandering around my tank. One is a larger purple crab that seems content to graze on asorted algea. One is a hairy tan coloured fellow that is in hiding most of the time. And the last is one I found the other day that seems to be hiding out in the sand, he is also tan in colour. All are around 3-4cm wide plus legs! Finally today, I found what seems like a tube-trail with little pieces of rock on the outside. It looks like some kinda worm is boaring through liverock and chowin down on corals. I could use some help on ideas on how to remove the "undesireables" from my tank and if possible some IDs. Should I be concerned of the crabs?
Thanks for any and all help in advance.
Shawn

[Wingin It]

I heard somewhere that if the claws of the crabs are pointy that they're bad. ;)

[untamed]

I don't know where "RMH" is...but if it is near to Coquitlam, BC you are welcome to add all those critters to my tank if you get them out alive.

[MMAX]

I would guess Rocky Mountain House, AB. I had a hairy crab like you describe in your post and he was harmless. Never ate corals and he would take shrimp pellets right out of my fingers.

[infamous]

I've also seen a similar purple crab in my tank. I've only seen him for about a day and the most I see is his claw, seeming to rip off algae from the rock and is quite shy. Is this similar to the one you might have? I would also like to know the ID of this little guy!

Otherwise, I'm not too much help for your hitchhiker problem, but I'll google it and post you anything I can find out. Good luck with more ID's!

[MMAX]

Purple or blue? There are blue porcelain crabs with small dark colored spots. I have one in my 20gal that's very shy but you can see him once in a while filtering particles out of the water with his "fans".

[Kryptic4L]

" One is a hairy tan coloured fellow that is in hiding most of the time "

sounds like a gorrila to me, used to hijack my zoas in the middle of the night.

[H2o2]

Both j+l and ocean aquadic have aqua medic pest trap so bait it up put it in put the ones you like in your sump (until you finish the deadliest catch)the ones you dont like fined a buddy with a trigger and bobs your uncle