Not sure what these might be - ID help please

[kmwcane]

I noticed the "creatures" pictured in my sump (have only seen them in my sump so far) and have no clue what they might be. They are attached to the walls of the sump, do not appear to move and have tiny filaments around their mouth region. Most are less than 1/8" in size and are all an off white color. Any thoughts? Thanks in advance!

 

[Everything Aquatics]

Pineapple sponges

 

[El_Guapo13]

Pineapple sponges

+1 on them being pineapple sponges. Harmless filter feeders. Hooray for reef tank diversity of life!!!

 

[vetteguy53081]

A sign that there is good water quailty present. If they become a nuisance, simply remove edge of an old credit card

 

[kmwcane]

Everyone - thank you for the replies! I was terrified that I had some deadly and invasive pest... This is my first reef tank so everything that is unknown is scary to me!