As a river blue catfish addict (always starving for answers), find it interesting to compare girth to length weight differences of what we catch. Shows in pictures we share that blues caught by me here (Mo. river in Nebraska) seem to be consistently "leaner" than blues caught in the lowest stretch of river. Been consistent during all seasons throughout the year and not a seasonal thing. I believe it gives important clues to their seasonal patterns and environment that they have been in that is otherwise lacking. Have to make our own observations as tracking studies for river bluecat in the Mo. is lacking. Think this is most important for bluecat as they are known to be nomadic,travel the farthest and so will void areas in favor of others. Lean fish might indicate: Fish traveled a distance to spawn & takes off weight to do that. Fishes food source requires more effort-energy to catch and bait size/type may not be the most fattening. Fish is using open water structure and not staying in one spot over a long period to get fat. The M.R. benthic fish study catch for blues here in Nebraska being low (compared to south) makes me believe there are less "resident fish" and that they spend energy traveling to/from during season.