What is this?

[flinster]

I’m guessing some kind of bristle worm, but I didn’t know they could propel themselves through the water. Thoughts? Found it when cleaning my filter sock.

 

[AydenLincoln]

You are correct there are many different species. I am unsure which one this is.

 

[rayadog]

What the sit down! The undulating, I was like okay. But then the dart! Excuse me. Should not be able to do this. Surely, they can’t all do this? They can’t right? Right?

 

[Gumbies R Us]

@ISpeakForTheSeas

 

[fishface NJ]

A bristle worm with super powers! LOL I hope that is the only one in your tank.
I QT any live rock that I buy. I had a yellow worm that swam in the water like that while I had my live rock in QT.

 

[BryanM]

looks like a bristleworm to me. I leave them in, unless they are fireworms.