Yellow Growth

[dlsrks]

Does anyone know what these are? Two started growing out of my rock. They look they have tentacles. Sorry about the bad picture.

 

[Breezyrae]

Pineapple Sponge maybe?? If that's what it is, they are harmless filter feeder

 

[melosu58]

Agreed it`s a sponge. They are good filter feeders.

 

[dlsrks]

That's for the input. How big do they get?

 

[grinder]

That's for the input. How big do they get?

If it is a pineapple,you can see an explosion of them,but they tend to be short lived getting no bigger than what you see.If it's an encrusting sponge,the lifespan and size will depend on the nutrients it recieves.