I caught a fish with this condition last season. Did not know what it was at the time. The walleye had actually been recently attacked by a larger predator fish and i thought at the time the discoloration was related, ie) trauma. It was most likely sandy flesh disease based on pictures and description. That was the only walleye I have caught with this condition... to the best of my recollection. I wonder how long it has been effecting fish on the SLR? Sent from my iPhone using Lake Ontario United