Zoanthid predator?

[Joe Lydon]

I will do my best to describe, because there was no time for a photo. I went to check out the tank a couple hours after "lights out". I noticed a hairy something creep away into a crevice and disappear. It was neutral in color and moved seamlessly/fast. All I could really find about predators, were zoo eating nudis... Well, needless to say, I noticed a very fine black string coming from the mouth of 4 zoa polyps and connecting one another. I tried searching last night, and only came up with the notion that it's excrement. Today, those zoas are shriveled up and the only ones not opening. I did notice a fairly large bristleworm about 2 weeks ago, it was black and white in color and much larger than the thing I saw last night. Whatever it was, I beleive I caught it in the act and scared him off.

 

[ReefJunkie1015]

Could be a Zoa eating Nudi... Which can also camouflage itself as the color of the Zoa's sometimes you won't even notice them. The other description could be a nasty fire worm I would suggest searching them out and getting rid of them. They can attack your fish at night while sleeping, then you'll be wondering my fish went MIA...