weird thing casts web to catch food

[paats]

I don`t know what this thing is but it lives in a tube with a hinged top.It secretes what is apparently mucus to form a web almost as a spider would do.When a piece of food gets caught it reels the web in till it can reach the tidbit.It`s bothering a Xenia on the same rock but I hate to do anything till I know what the critter is.

 

[Sidewinder]

By your description, it sounds like a Vermetid snail; I believe that they are beneficial ...

 

[Anonymous]

pics?

 

[horge]

operculum? tube? mucus capture?

I agree it sounds like just another vermetid gastropod.