DD has a tank in her room and in it were 2 platy and 2 dannio. The platy seemed v calm and happy, but the dannios just didn't seem to have the room they needed to zip about, so were relocated downstairs into the 4 foot tank in the dining room. She replace the 2 dannio with another (donated) platy boy.
They seemed to stress out my calm and placid tank by zipping about and I hadn't actually wanted dannios, so I donated them to someone else.
Back to my DD's room.... I was helping her with a water change today. There, swimming among the platys and the plants was a tiny fry. It can only be a dannio fry as the platys are both female and the male hasn't been in the tank long enough to do the deed. It doesn't look like platy fry either.
So we can only assume that, unnoticed, the dannios must have been a male and female pair and they had spawned and this fab little fry is the result.
Awww......
DD is very proud of her 'baby' and is planning to keep it. :)