I forgot to mention… I also got a Mystery Snail.
Yesterday, I thought I killed it.
See, the glass lid sort of slipped as I was manhandling it, and it fell into the water. This wasn’t a huge worry, just a pain – I fished it out again and all was fine. However… a little while later I was ogling the tank, which I do sometimes, and noticed the snail was not looking good. Like not attached to anything. And no gooey bits showing. And THEN… he sank to the bottom of the tank! Oh no, I thought! He’s lost buoyancy, which surely means he’s dead! AND THEN: he started falling out of his shell! As you can imagine, I promptly thought about bewailing my misfortune and how bad a fishkeeper I am (because it’s all about me, not the fish and/or snail). However, I decided to delay that a little and see what happened with the snail. What happened was that he finished turning himself around inside his shell, bringing the skirt-bit back to where it usually is rather than protecting his innards, and proceeded to suck scum from the bottom of the tank.
Snails are a lot more complacent than their owners.