Unresolved Need help identifying zebra striped hitchiker

I bought my first piece of coral, a monti cap, yesterday from a fairly reputable LFS. It didn't look bad in the display tank at the LFS, but it was towards the end of the day and their lighting was tapering down so I guess I didn't notice.

Anyway, to be careful, I shook the frag for about 8 minutes in Coral RX mixed w/one gallon of my aquarium water. To my surprise, this morning, the piece is covered in tiny aiptasia flowers and has a few unidentified legs coming out of it.

The legs are like extremely thin bristle worms, but are banded black and white like a zebra. I see 2 legs at the momment. I'm assuming this is a tiny brittle star? It came out when i fed cyclopeez so it (and the aiptasia) definitely made it through the Coral RX wash.

Can you guys help me? I took a close up and distant shot for size reference. The frag is about 1.5".

Also, what should I do about this aiptasia? I'm sure its already infested after a night of my vortechs blowing on it.

 

Looks like a brittle star to me.
For the aiptasia you can use aiptasia x or peppermint shrimp

 

+1 agreed. and nice looking Spongodes

 

Spongodes? Is that what it is? Given it's apparent aggressive plating growth I assumped it was a cap of some sort. The spongodes don't look like they really plate. Here is another picture taken with my iphone from the front of the tank.

 

That's not spongodes, it's a green cap of some sort. Looks sort of like a green apple cap. Pretty piece.