Last night when I went to bed I checked all my tanks as usual every tank was fine all fish were fine. Late last night around 2:00am I went out to my kitchen for a drink of water...on the way is my living room where my dovii tank 240 gallons is located . I glance over and see the female dead on her side resting on the tile....I was so upset. When I went to bed she had eaten and was doing fine....these dovii were raised together...they paired naturally. They NEVER fought. They had spawned before and she was ready to lay again any second. No visual signs of fighting. Ammonia 0ppm nitrate 0-20ish ppm (closer to 0ppm) nitrite 0ppm. I am hitting myself in the head because I didn't hang on to any fry from the first batch( assumed I would have far more to choose from in the future) now I am without a female. My male is now Very VERY skittish and scrambles when I even get near the tank. Such a sad day.....one fish gone another left with a complete personality change.....I'm guessing I can never expect him to be the wet pet he was before ever again? I don't know....