Is this some kind of sponge?? O.o

[MaraRavenous]

So recently some weird growths have been appearing around my aquarium, sort of all over the place. They are soft, kind of porous, and an off white color, but seem to grow blue after maturing for a while. It seems the feather dusters of my aquarium find them ideal places to root into as well. They‘ve even been growing on the underside of some of my LPS, and I’m not sure if I should be concerned. They scrape off and have a soft, jelly like texture. Any help is much appreciated.

 

[blaxsun]

From what you describe it sounds like sponges, yes. For the most part harmless and beneficial to your reef.