Warning: The following statement is purely speculation.
I think it's the same reason the bucks have different variations of antler size, length, girth, width, etc. Every male is essentially taking his own unique approach to attracting a mate. Different girls like different kinds of guys. Eventually, through selection over hundreds of generations, the males settle on a general theme that advances their species through ability to reproduce effectively. Variation however still drives evolution.
I am curious as to the relationship between changing light conditions and fish coloration...Sun going in and out of the clouds and how we percieve or see fish color and how fish may react "emotionally" and express their colors along with the changes...I am curious but dont know anything.. Ha !
I can agree with Bruce's logic, however - Bluegills are like a "Living Mood Ring" - and their color at any given time seems to reflect their dispoition.
I think it would be very interesting to tag a few 'gills - and catch the same ones at different times, photgraph them and see if they, themselves have different colors at different times - or see if they seem to adopt a specific color scheme.
I have a gill in an aquarium for this reason. AND YES THE MOON HAS AN EFFECT ON THE COLOR! If I keep the temp at the 72 mark he throws on a bright chest 3 days before the full moon.
HAAAAAA.... HAAAA HAAAAA! Thats awsume. I will have to remember this one to tell other folks. Oh Lucky me. Wheres some wood to knock on. Im blessed with the I need a hair cut every other week people! I love the glass half full aproach though!
Well now, IMPO, sure, I think that the fishes mood, the water temp, whether or not the fish is spawning, etc, will affect the fishes coloration.
> However, I think if you look at a fish (just for an example, lets say, like shot #4 from above) at different times, it's color would range from darker, more colorful, and with more contrast, to paler, with less contrast.....
But I do not think and individual fish would vary from say the colors of fish #4, to say, fish #3.
I could be wrong, but I'd almost bet my new truck on it :-)
Bill, Bob Davis from the Rock Lake area. Didn't know how to email you so decided to jump in and let you know the big gills are staging for suspension right now. They are being taken in 12-15 feet of water on the edges of most of the drop-offs and out on the structures that are about that depth. Also I'm off work the entire week of June 29th thru July 3rd so will be fishing most of those days if you're interested in coming up this way. You have my phone #. Sincerely, Bob