Polyps

[lynieboo]

Why have the polyps closed and have what looks like white fuzz on them?

 

[icedgxe]

They look like pineapple sponges to me.

 

[ISpeakForTheSeas]

They look like pineapple sponges to me.

Yeah, those are pineapple sponges - they're harmless filter feeders; if they're physically touching the polyps (not just near it, but touching it), they might just be physically irritating them, and that could potentially explain their closing.

 

[lynieboo]

They look like pineapple sponges to me.

Ohhh, could they have been there in the rock when I got it? I never seen them and about a week ago there they was so I thought it was some thing wrong with my polyps.

 

[ISpeakForTheSeas]

Ohhh, could they have been there in the rock when I got it? I never seen them and about a week ago there they was so I thought it was some thing wrong with my polyps.

Definitely possible that they were on the rock and just microscopic when you it:

They can regenerate from cells, so if their cells are on you fish, snail shells, macroalgae, etc. (basically anything wet), then they can find their way into your tank and start growing into new sponges.

For a good example from the genus:

Regeneration in the sponge Sycon ciliatum partly mimics postlarval development

Highlighted Article: Sponge regeneration is as dynamic as embryogenesis and can be explored to study the genetic features underlying the evolution of multicellularity and regeneration.

journals.biologists.com

 

[kevgib67]

They typically show up early in a new tank and then go away without intervention, harmless.