WORD OF CAUTION WITH APPLE SNAILS AND ACF!
I nearly lost one of my ACF due to an apple snail - - when the apple snail gets startled, ex: frog swims by it, the snails closes up instictively. Their trapdoor is made out of the same material as their outer shell and is extremely hard to break.
My male ACF Louie, startled a snail and it instictively closed up - and accidentally caught Louie's arm in the process. Due to the weight of the snail, the frog could not surface for air and was on his back, drowning, when I came home from work.
The problem was, not only was it stuck where the trapdoor meets the outer shell, but snails twist when they retract into their shell and his arm was twisted inside the snail. Also, the weight of the snail combined with the panicked frog caused the arm to be thrashed, twisted and pulled. It was several weeks before color normalized and the frog regained full use of his arm.
It took nearly an hour to free the arm of the frog from the snail. Unfortunately, we had to sacrifice the snail to save the frog but it was a decision I had to make. Towards the 30 min mark of us trying to pry the snail open, the frog had become listless (went into shock) and we could no longer put off the inevitable - prying the snail apart with pliers. We had to rip tiny pieces of the shell off at a time to free the arm, it took so long because the broken edges of the shell were exceptionally sharp and could have severed his arm if he jumped during the process.
Note, these pictures of his healing are taken more than a week after the incident.
Needless to say, you have not seen a snail in my tanks since.