I've been married for 29 years. I talk to myself a lot. It's safer than saying it out loud where somebody else might hear me. lol

Do a google search for #10 grinder plates. The 1/2" plate does a pretty coarse grind on beef or venison. I expect they would do the same with fish.
Depending on the size of the fish you might need to chunk it up for it to fit the grinder throat.
I've pondered pulling out my #22 electric grinder to grind up some carp for freezing into chum blocks.
The next time a bunch of those crazy silver carp jump into my boat I'll bring some home and try it.

I asked one of the RES why he kept spitting pellets. All he said was glub glub. I don't know what that means.