Please help ID.

[anyuser]

These fuzzy things are growing rapidly in my refugium and in the low flow areas of my sump. I first found them growing in some chaeto that I added to my tank. They don't seem to be a casing of any sort as I've never seen any creatures in them. They are made up of fibers that are easily pulled apart. Does anyone know what they are? Are they bad or good?

 

[reefmanic]

harmless sponge

harmless sponge

i've had these before that entered with some LR,never had a problem with them and they seemed to stay in the sump area or other dark area's

 

[Pea-brain]

Harmless pineapple sponges. They just filter feed and usually go away for the most part as the tank matures. LIke low light places.

Dan

 

[urville]

My LFS has one that looks just like that except round... like it's spun from glass.

 

[anyuser]

I appreciate the replies guys. Pea-brain, I believe you have correctly identified them as "pineapple sponges", a.k.a scypha sponges. Before I made this post I had tried tons of internet searches but it was futile since I didn't know they were sponges. Thanks!