Monti and Chalice Killing Worm

[undermind]

I've searched all over to find info and have found nothing.

I noticed a dark spot at the base of 2 out of the 3 Monti frags I have in the tank. They were smaller than a BB. They've grown slowly over several months and I didn't pay much attention to them as they were hard to see, and the corals were fine.

Over the last 2-3 weeks, the spots have picked up their growth rapidly, while corals declined. I lost 2 Monti's and one chalice, all with an attached spot, which I can now see is a tubular dark red spiral shell. Upon removing the shells by hand, I see there is a single black worm inside.

Thoughts?

 

[Mjrenz]

I'm not an expert on critter id but I believe that is a vermatid snail

 

[undermind]

I'm not an expert on critter id but I believe that is a vermatid snail

That's where my search began, but I discounted it when I read that they cast a mucus net. These guys have never done that (I've seen the mucus stringers before).

That said, I think you're right. Looking at images, that looks like what I'm seeing, just minus the mucus net.