Okay, so two days ago one of my guppies unexpectedly gave birth. I managed to save 17 and put them in their own tank. One of my fry is darkly colored, and he/she is always sitting in the bottom edge of the tank. He/she doesn't swim away when I tap the side of the tank. If I pick up the tank a little, he/she appears to be swimming, but could it just be the current? He/she just goes right back to the bottom, but yesterday, if I picked up the tank, he/she did laps around the top! Is he dead? I would like to know ASAP so I can take him out.