Could this be a baby feather duster?

I have one feather duster in my tank and it was hiding in the rockwork for a while, I thought it was gone. Then a couple days ago I moved some rock while taking my skimmer out and I found the duster. That was great news, but now I noticed these little things on the glass that almost look like baby dusters. There are probably a dozen or so that showed up overnight. The look like they are attached to the glass at the base and then have a small crown that is almost shaped like a feather duster. Maybe it's something else, maybe it's nothing. There were none on the front glass so the only picture I could get is not real clear. Thanks for any help IDing.

 

It's possible! Can't really tell by the photo...they grow and spread quickly as they are filter feeders and have no trouble with feeding requirements.

 

It could also be Aptasia anemonies. If they are, they're pests. See the thread "new fish, new rock, new problems" for ideas on how to get rid of them.

 

Yeah I guess I'll have to see what it turns out to be. They are on the glass though not on the rocks. I've had these rocks for a few months and they were out of an established tank before that so I doubt its aeptasia appearing now.

 

I'm going to guess that they're fan worms and not baby feather dusters even though the pic is very blurry. If they are fan worms, they won't get much larger than they are now.

 

um... fan worms are feather dusters.

Fan Worms & Feather Dusters (Annelids)

 

Fan worms, to me, mean the type that remain small, have white "feathers". Feather dusters, to me mean the type that have colored "feathers" and come in dwarf and giant varieties. Hope that clears things up for the original posters.

 

it doesn't really matter what ya call em really, I've noticed a lot of salty critters are called different things in different places. We have come to the conclusion that they are definetly WORMS!

 

all are classified as polychaeta, one of the major classes of annelids, all varieties are commonly known as feather duster worms.

four families:

sabellidae (tubes formed of soft material, larger crowns)
serpulidae (tubes formed of calcium, double crowns/helix)
spirorbidae (small tubes, colorful crowns)
sabellaridae (tubes formed of substrate, smaller crown)

hope that helps,
jonathan