pocillopora crab

[Foofalak]

I got a small colony of pink pocillopora today. At the store I noticed the crab in there. I asked the guy and he said it should be fine (likely answer). Well I've found something on the net that resembles the crab I have. heres a link to the picture

http://www.imagequest3d.com/pages/articles/trapezius.htm

he's the guy with the blue-ish body at the top of the page taking on the crown of thorns star fish. So, I read the write up and understand the relationship between the crab and coral, but is it necessary in an aquarium? since he feeds a bit on the coral, will he do more harm than good since I don't have nasty predators for him to fend off?

Just looking for a few opinions. Right now he's in a bowl of salt water and the coral is looking good in the tank.

thanks

[Foofalak]

for now I'm going to put the crab back in the coral. he was easy to remove the first time, so hopefully the second too if necessary. Would still like to hear back from you guys. still new to the game, and always happy to get some advice.

thanks again

[Atomikk]

They also 'clean' the coral. I would keep it.