Well I was looking in my tank and noticed my female mandarin acting weird. I then notice my normally fat happy male mandarin wasn't looking so good. His fins looked jagged and he was laying on the bottom barely breathing. The female was bitting him. It actually looked like she was biting his eyes. I can't figure out if she was attacking him or trying to get him to go with her. They were just starting to seem like a "pair" ;( Unlike a lot of mandarins, he was out and about 99% of the time. She was starting to be out almost as much as him as of late. I have no idea what happened. He was one of the fattest mandarins I have ever seen! She was quite a bit smaller than he was. I've had him for 2 years and her for about 8 or 9 months.