Mystery snail mystery death

[cappa565]

Okay guys i have a major issue in the past week both my mystery snails have died. My small one was found 3 days ago with an empty shell and the big one was found ripped out of his shell! They have both been fairly inactive for 2 weeks. Water paramiters are fine! Ph is at 7.5 and i have added no new fish in over 6 months. These snails have been in the tank for over a year now. I have 2 firemouth cichlids 4 tetras 3 kuhli loaches and bristlenose pleco.
What could be the issue

 

[Toad]

What exactly are the water parameters? Over all, I'm guessing the firemouths, but snails will fall out of their shells when they die regardless, especially if the fish start scavenging

 

[TMaier]

Snails do not have a long life expectancy. Mine generally live 18 months from hatching. Yours were probably at least 3-4 months old when you got them.

When they die their bodies decay quickly. Often nibbled on by tank mates and pulled from the shell.

Sorry you lost your snails.[emoji26]