Oh, lol, misunderstood the title for a second. I have one angelfish that sleeps on the ground on his face. ( I thought he was dead when I saw it first) I think its on account of the broken dorsal fin he has had since I got him.
Nice tanks, your picture will pick up better contrast if you can keep the lightsource out of line of sight of the lense, maybe hold the camera a bit higher.
What size is the one on the right? Looks like a large tank.