This time there were no losses, but I had failed to realize that the opening at the top of the bottle would be tempting to swim into. Once inside, the lone fish seemed happy enough to live out its life, but it became decidedly unhappy when I decided it shouldn't.
Looking at the fish in that photo, it also appears they have grown compared to this picture from the day after I got them. I'd best find out if they could have grown a noticeable amount within only two weeks. I need some way to measure them without disturbing them.