Is this a sponge??

[Algaewarrior]

I have had this rock cycling for about 4 months now. Dry stax rocks and I already have a good copepod population as well. These popped up this week. They kind of look like clear zoanthids. Sponge?

 

[James M]

You’re correct..that’s a sponge. They are harmless filter feeders

 

[Algaewarrior]

You’re correct..that’s a sponge. They are harmless filter feeders

Thanks. I have a few in my biocube. Pineapple and some green one that came on a frag. Definitely not going to remove them. They are super cool imo. Just wanted some confirmation.