Coloration within a fish species quite often varies from one lake, river or stream to another. Sometimes these color differences are so slight they can hardly be distinguished from one location to the next. In other cases, the distinction is so prevalent, the fish can appear to be a variety of the same species; but to my knowledge the variance in coloration is simply a camouflage adaptation to match the general color of the bottom of the body of water.
Fish Wear Camo Too
This unretouched photograph of a prize large mouth bass was taken on a rather dark, grey day. The particularly dark coloration of near black on this bass, however, is typical of MacArthur Reservoir large mouth. It’s a species adaption that allows individual fish to blend with the dark color of this shallow bird sanctuary where fish hawks are plentiful and capable.
~Dwayne K Parsons on Twitter @IFishWrite