Do feather dusters kill snails?

[PotatoPig]

I recently got a batch of Astraea snails and have them in invert QT. One of them died - shell stopped moving around and was in the same place for a few days then I noticed there’s a now little feather duster living in/on the shell.

Do these things predate on snails, or was this a weird coincidence?

Brown and white duster on bottom-left of shell:

 

[ISpeakForTheSeas]

Do these things predate on snails, or was this a weird coincidence?

Almost certainly a weird coincidence - feather dusters are pretty much exclusively harmless filter feeders (very few exceptions that I've found to that, though I know at least one at the moment that seems indirectly harmful). I've yet to find one that's a predator.