Is this a sponge?

[Prevailing Reef]

I have a couple rocks that have been in my sump for 4 years. Moved my skimmer to clean it and noticed this large mass growing. It definitely feels “spongy”. Is it a sponge?

There is also a lot of hairy type stuff growing everywhere. Are these all various types of sponges?

 

[Reef Wizard]

I have a couple rocks that have been in my sump for 4 years. Moved my skimmer to clean it and noticed this large mass growing. It definitely feels “spongy”. Is it a sponge?

There is also a lot of hairy type stuff growing everywhere. Are these all various types of sponges?

It is indeed I have same stuff all over my rocks

 

[Prevailing Reef]

It is indeed I have same stuff all over my rocks

Thanks, I assume leaving it will be beneficial.

 

[crazyfishmom]

Pineapple sponge I think… harmless filter feeder.