Help Identifying These White Critters In My Sump

[Mkissane]

Hello! Last night I noticed these growing in my sump in the high flow intake chamber. There are pineapple sponges, but I have no idea what the white star looking creatures are. I could not find pictures online. If they are bad how do I treat? Aside from minimal algae issues in the 180 DT everything is stable. Sump is 20 gallons. 9 fish, a few acros, many montipora types and RBTs. Tank is 1 Year post major move, 18 months total up time.
Alk 8.5
Ca 400
Mg 1420
Nitrates undetectable as hard as I try to raise
Phosphates .02-04 consistently
Temp very consistent 78

I tried to provide the basics. Thank you in advance.

 

[OriginalUserName]

I'd say that is also some type of sponge.

 

[shred5]

I'd say that is also some type of sponge.

I agree it looks like some sort of cryptic sponge.

 

[Mkissane]

Thank you so much. They looked scary. If they make it into the DT I hope maybe my Flame Angel or Mystery Wrasse eat them.

 

[Drb402]

Anyone have any idea what this is? It stays in the same place, looks similar to a baby clam in shape but has polyps all around the top edges?

 

[KJ]

Anyone have any idea what this is? It stays in the same place, looks similar to a baby clam in shape but has polyps all around the top edges?

Picture to blurry for positive ID.