The Wrasse is difficult to get, one day I'll get him in focus properly.
Distance wise these are taken at full zoom (55 on a 18-55 Nikkor lens) as close as the camera will focus, probably about 8 inches away from the fish or crab.
I like the shot of Pinchy the crab as well, he's about 3/4 inch wide in real life so pleased how the macro turned out, also pleased with the Starcki photo, the rest I'll keep trying with until I a get a crisp shot. The problem is the tank is in the centre of the room so the naural light is fairly low, and therefore the movement of the fish creates a small blur. I don't like to scare them with a flash!