Eggs? Sponge? Other?

[Idaknow15]

Hi all,
Spotted this tonight on the “dark side” of my tank and no idea what it could be?! Looks like a spider egg sack but I can’t find anything similar online to tell me what it could be.
Just wondering if it should stay or go but it’s on one of my lowest rocks so will be a faff to remove if not necessary!

 

[vetteguy53081]

Hi all,
Spotted this tonight on the “dark side” of my tank and no idea what it could be?! Looks like a spider egg sack but I can’t find anything similar online to tell me what it could be.
Just wondering if it should stay or go but it’s on one of my lowest rocks so will be a faff to remove if not necessary!

Poriferan sponge and in typical spot- Shade
I remove them but really of no harm. Some sponge are filter feeders- this one is not

 

[WheatToast]

Some sponge are filter feeders- this one is not

Could you please elaborate? How does it feed?

 

[vetteguy53081]

It captures detritus and bacteria delivered by water movement to their cells

 

[WheatToast]

It captures detritus and bacteria delivered by water movement to their cells

Sounds similar to filter-feeding; is there something I am missing about this process that differentiates it?

 

[damsels are not mean]

cool sponge nice