A Sewer I Particularly Don't Want to Visit

Oh my. It's not as if I've ever spent much time in sewers (though in high school, I did have a habit of exploring the storm drains in my home town). But this is too creepy:

The blogger who found this claims they're bryzoans, but doesn't explain how he's confident of this. Other suggestions in the YouTube comments include cnidarians (jellyfish, coral and anenomies are examples), land snails (slugs), and slime molds, among others, and of course everyone is suspicious of CG shenanigans. The comments are looking through for a while; some are very witty and funny. Here's an excerpt from a thread that cracked me up:

dat1337vet

I say we take off and nuke the entire site from orbit. It's the only way to be sure.

benscottproductions

Game over, man. Game over, what the F are we supposed to now, huh, what are we gonna do?



kingpig21

Maybe we could build a fire, sing a couple of songs, huh? Why don't we try that?

fresshness2001

ok look, this is an emotional moment for all of us, ok? I know that. But let's not make snap judgements, please. This is clearly, clearly an important species that we're dealing with and I don't think that you or I or anybody has the right to arbitrarily exterminate them. Look, I'm not blind to what's going on, but I CANNOT authorize that kind of action, I'm sorry.

Followup, a couple hours later... I found this quote on another blog:

Thanks for the video – I had not see it before. No, these are not bryozoans! They are clumps of annelid worms, almost certainly tubificids (Naididae, probably genus Tubifex). Normally these occur in soil and sediment, especially at the bottom and edges of polluted streams. In the photo they have apparently entered a pipeline somehow, and in the absence of soil they are coiling around each other. The contractions you see are the result of a single worm contracting and then stimulating all the others to do the same almost simultaneously, so it looks like a single big muscle contracting.

OK... whatever it is, you're sayin' this is fer realz? I've fed Tubifex to fish before... I don't remember them looking like the above.