Sponge or Anemone foot?

[BTimms]

Hi all.

To I adjusted my flow by accident while doing maintenance. And my BTA decided to go for a short walk up the rock. This unveiled the creature or thing in question. Please see pics.

Is it a sponge that had been covered by the anemone or did the BTA leave something behind? Should it be removed ?

Thanks in advance!

 

[MichaelReefer]

Looks like a sponge to me.

 

[BTimms]

Looks like a sponge to me.

Any idea as to what species it is?