I'm also curious. I have my BGK in the freezer, died when I was on vacation and the heater crapper out. Loved that fish, and it has to have a really cool skeleton since it's a knifefish.
Also possible with ants. Leave it in your backyard atop an ant pile covered by a bucket with a heavy object on top. (In case something tries to eat the fish)
Good question. I have a turtle, who died a few months ago, that i want to keep her shell. She's been sitting in the freezer. I heard ants too, but i feel bad just ditching her outside to be eaten by ants. Yea she's dead, and it's free, but... idk how i feel about that. Anyone do turtle shells?