This is the black Sunfish. If I remember correctly, when he was smaller, he was normal colored with a black patch that encompassed his entire dorsal fins and came partly down his sides. As he has grown, he has turned completely black. However, I didn't see him at all since last winter up until a few weeks ago so it could be a different fish, but I doubt it. The black spot was growing progressively larger has teh fish grew, so I assume it is the same. Also, we built this pond and stocked it ourselves, so I dont know of any foreign fish that it could be, but again I could be mistaken. We feed our perch 50 crickets almost every friday and therefore they are very accustomed to us and will swim up to us to feed, so I will try to catch him and take a picture of him out of the water soon