White semi translucent spherical objects attached to rocks

[Mr Llano]

Today I noticed a bunch of white semi translucent spherical objects attached to rocks in one of my tanks they look almost like tunicates the only other thing I can imagine is that they are baby sea urchins

does anyone have any insight into this

 

[Cory]

Pineapple sponges

 

[Mr Llano]

Where could they have come from?

 

[Cory]

From live rock. Or on a frag plug. Harmless filter feeders. Good for the tank.

 

[Mr Llano]

Thanks