Neomeris is an alga. I don't know of a good predator. From the thread, I thought you had a tube worm.
If the tank has a tube worm issue, you might consider trying a peppermint shrimp. There's some chance one might eat your problem away. I've watched mine eat tube worms. There are lots of fish that eat tube worms, but many aren't reef-safe or are marginal, like the copperband butterfly. The copperband is also difficult to keep alive.
Can you post a clearer shot of the organism in question?