? snail on tube anemone

OK for the last 3 days I have had the same 2in in size snail in the same spot on a tube anemone.
the snail is hanging on the very top edge of the tubes protective build up it goes in and out of.
when the tube retracts in the snails weight closes it completely of.
the tube does make his way back out but should I remove the snail from where it is attached?
then risk the tube pulling in and coming up somewhere else where I don't want him and may not beable to see him like behind my rock work.
What do you think any else had this before?
Thank you

 

took the snail off of it looked dead set it on the sand bed to see 1 hour later a crab in my tank had it turned over and was picking at it's insides.