Hydroids? Not sure.

[Srfnhooker]

Hi all.
I have these growing near a mushroom and it doesn't like the critter there. Probably stinging the mushroom. I'll be removing the critter tomorrow but I was wondering if anyone could identify it. Thanks.

 

[dwest]

They look too long for hydroids. But not sure. If they are almost wholly attached to rocks I’m guessing sponge but really unsure.

 

[Glenner’sreef]

Sort of agree!

 

[Srfnhooker]

They look too long for hydroids. But not sure. If they are almost wholly attached to rocks I’m guessing sponge but really unsure.

Yeah. Attached to rock. The mushroom has pulled back and won't touch it. Going to remove whatever it is.

 

[Srfnhooker]

Update - Removed whatever it was and the shroom is fully opened now and color has returned to normal.