From information that I have read by a leading authority, the perch is most likely blind. This happens every know and then with sunfish. Because a fishes color is largely based on its surroundings, which is interpreted through vision, the fish is most likely blind which results in the fishes coloration being black. When I throw crickets, he usually sits there and doesnt do anything but slowly go towards the general direction of activity and wonders around slowly. Also, he is sitting on top of the grass 90 percent of the time and is very slow to move/react. Blindness helps to explain this, but I'm curious how he has survived so long unless his blindness was progressive which would explain the gradual change in coloration.