I've got a Halichoeres melanurus. I can't confirm that it eats flatworms, but I've never seen one in the tank. It plays nicely with the other fish, just not another wrasse. I've got a cleaner shrimp and fire shrimp that it has never touched. It's an all around beautiful, inexpensive reef safe fish, although it has been known to throw around some snails. It's never touched a coral.