Bomb, I'm so sorry, too. AND sorry for the gross-out factor. When you can just get their body out & put it in the garden quickly, it makes it easier. I lost my white girl, Flake, last week. The white ones' seem to catch all the colors...sooo pretty :0(
I've had a fish disappear, except not a betta: 1 cory and 1 LARGE Amno shrimp. The shrimp were in a .5 gal QT tank alone- if the others ate it, it certainly must have been within :30!
An interesting note: my name is Melissa. In high school, my best friend was named Andra. She died of a sudden illness in the October of our Senior year. I was considering naming my 1st baby (human baby) "Andra" but he was a boy. I never got around to having a girl.
4 bettas: Butch, 3-year-old violet male PK EE & 3 girls in a 30 gal sorority. I do not name the girls anymore! 1/2 of them die within a month.
30 gal: 9 Oto cats, 4 Ocellifer cats. Inverts: Cherry shrimp & 2 assasin snails.
10 gal.: Butch, his 5 oto cats, 3 assasin snails, and a few snails the assassins haven't caught.