What are these?

[Jsmith79]

There are a bunch of these in my refugium, they look like small tubes
with bristles coming out of the top. Does anyone have any idea
what they are? They don't appear to move at all.

 

[carey]

I believe they are pineapple sponges, harmless filter feeders.

 

[Jsmith79]

Good to hear they had me worried, there are hundreds of them all over
in the refugium, but none in the main tank.

 

[carey]

I have then in my sump all over and in my overflow on the sponges too. Hundreds of them. They are also in and around my skimmer too. lol