Unidentifiable creature, worm maybe?

[ss_alpena]

I’m completely at a loss as to what this thing is. My best guess is some sort of worm. It seems to be sessile, and it extends this long, singular, stringy thing with hairs that remind me of a sundew. The base does seem to be soft as it sways a little with the, uh, appendage. Right now there’s about 4 of them in my tank. I assume it’s a harmless filter feeder? They grow either on the rocks or sand.

 

[kevgib67]

I’m completely at a loss as to what this thing is. My best guess is some sort of worm. It seems to be sessile, and it extends this long, singular, stringy thing with hairs that remind me of a sundew. The base does seem to be soft as it sways a little with the, uh, appendage. Right now there’s about 4 of them in my tank. I assume it’s a harmless filter feeder? They grow either on the rocks or sand.

Looks like a hydroid.