My tank is about a month old with two clown fish and a cleaner shrimp. One is a larger maroon, and the other a small Percula. They have always got along fine but oddly enough the small percula is far more active. Recently when opening the tank the percula swims to the top almost as if it wants to jump at me for invading his territory. At first I thought they were hungry but he didn't even care about the food until I put the lid back down and repeats everytime i lift it. Immediately after walking away he goes back to normal... is this normal? I also just read that maroon are aggressive and there might be a problem down the line which is annoying because my reef shop said they would be fine.