A while back, I had a large lake trout hit a large lure......the fight felt like a big one but
lasted only seconds and left me with some dead weight on the lure. The trout had
half swallowed a 3# whitefish and the tail was still sticking from the trout's mouth.
My jig hook had hooked the whitefish tail and I pulled it from the trout.

The tail and back half of the whitefish were still intact but the head and body were
digested down to the skeleton......that portion within the gullet had been eaten by
digestive acids......gotta be strong acids.