Pest or propagation?

[diveinheadfirst]

What is the tube coming from the bottom right side of this micromussa? Not sure what propagation looks like, but this guy always looks happy and healthy. Thank you for any advice and help, it’s greatly appreciated.

happy reefing

 

[eaquintero]

Looks like a vermatid snail, you can probably snip it of with some bone cutter.

 

[ISpeakForTheSeas]

Looks like a vermetid snail:

It looks like it may be vermetid snails - they're generally considered pests, as they reportedly sometimes irritate corals. However, it likely depends on the coral and the vermetid species, as some people have pics of their corals growing over the vermetids and doing just fine.