I'm a newby here, but I've been catching and eating bluegill for years. The way I have been killing them, is to whack them in the head several times with a club or the back of my Camillus four-blade knife.
I came across this in F. Philip Rice's book, "Panfishing."
"Bleed the fish by cutting their throats. This gives them a cleaner flavor. The fish, of course, will bleed more easily if still alive. (This is usually a more humane method of killing them than hitting them over the head several times.) The easiest way is to cut just behind the gills across the inverted V section. Cut deeply enough to sever the main arter behind the hear, or the heart itself, which is located just behind the gills."
Anyone care to comment?