Do you love big bluegill?
If anyone knows that, it's you, L! LOL
(Although I dont think even Cajuns would eat predatory water beetles!)
They live in a swamp, after all. Along with all the usual stuff, Nature offers them all sorts of other "comestibles." And when you're hungry enough, most anything looks good.
I used to find these things in my swim pool and would scoop them out. They can even withstand harsh chlorine shock to a pool so figured they wouldn't be good to swim with.