Astraea Snail growth?

[mikemathis555]

Have two Astraea snails as part of my CUC. I noticed either a growth or a body part on the bottom today - pic attached.

is this a normal body part, or something to be concerned with?

p.s. - I thought it might be an anus, but I wife thought I was crazy.

 

[Isopod80]

Looks like a tube worm attached to the shell. Harmless filter feeder. Definitely not an anus. Don't worry, he's not winking at you.