Early on in the saltwater hobby, I found tons of bristleworms in my tank. I really didn't like them, as they came squirming out of the rockwork and substrate at every feeding. So I bought a Longnosed Hawkfish - Oxycirrhites typus - to take care of the problem. And this fish did just that, he got every one in sight. However, it didn't decimate the population, because I still have them to this day. I just don't have to see them, unless I look late at night with a flash light. This fish likes to park in odd spots, like it is On Duty. :) Reef-safe!