worm id,need help please

I just walked past my tank and seen probably 60 or more of these just going crazy corkscrew swimming everywhere,in the amount of time i took these pics,more than half has been sucked through my powerhead and now the tank is completly clouded with near 0 visability.Are they harmful?????,did they just nuke my tank??????????????????????

 

I believe they are bristle worm spawn. Don't remember the name for the stage though.

 

They can swim like that?I saw no spines,but they were going nuts like some kind of mating frenzy or something.

 

It is an intermediate stage of some sort. Don't remember if that is basically an egg sack or what.

 

Well,i just checked again,and it's over,don't see any,the water is still fairly cloudy,all corals are open fully and lots of cuc are out and feasting i believe.That was the wierdest thing i ever saw in any of my tanks,they allmost formed a sort of bait ball and drifted right into my korolia,then it was like "poof",i'll do a hefty water change in the morning.Thanks for the help!

 

Probably a good idea. At least the coral got some food with out you having to feed.

 

Look up epitoke.

 

That is the word I was looking for.

 

It's a cool word.....

 

Epitoke is right. They're the sexually modified rear ends of eunicid polychaetes.