What are these things under my Ricordea?

[rarca]

I noticed these two “blobs” at the base of my ricordea musrooms and I are no idea what is it. at the tip, it appears to have tiny “tentacles“ that I am suspecting a mouth. Any idea? Thank you for your feedback.

 

[WheatToast]

Pineapple sponges (Sycon sp.), which are calcareous sponges. Harmless filter feeders that are common in new tanks. Sponges don't really have mouthes but they feed by drawing water through their ostia (pores) and out their oscula (opening at the top of the sponge), which is surrounded by very large spicules (the tentacle-like things) in pineapple sponges.