[Uncle Miltie]

I’ll bet money that critter lived directly below a hydro dam, and ate up the chopped fish (probably out-migrating steelhead and salmon smolt) that came through the turbines.

Extreme growth in a rainbow that causes a fat center like that is usually associated with extreme food supply.

[Hot Tabasco]

and ate up the chopped fish

Yea, that was one of the explanations given in the F&S article that was posted........