Justify this snail death

[EmilyB]

Long story short, amazing grip witnessed by a few people to the point we thought it had petrified onto the glass. Nope. It was very alive until I took down the tank and twisted it off.... This is the inside of its shell, the holes explain how it could seal itself. I want a dozen.

[fkshiu]

Isn't that an abalone shell? They're infamous for their death grips.

[NateL]

looks like an abolone to me

[Zylumn]

I watched you try and twist that thing off the glass while there was water in it. Cool was it a hitchhiker?

[andrewsk]

That is an Abalone.

[christyf5]

Abalone, best removed with a razor blade gently slipped beneath the foot at the halfway/three-quarters way point you can start to pry. Otherwise it is a done deal if you just rip them off, too much muscle damage for them to recover.