It must be a mutt

[DepotFish]

My red wag girl died. I've got a male gold bar platy and a female something left. She's lavender in colour and gorgeous. I wish I could get a picture. She looks like a cross between a guppy and a platy. She hasn't gotten pregnant yet, so I figure she must be some sterile crossbreed. Boy I wish the odd ones could reproduce.

[Zagz]

Sometimes the odd ones are a cross between 2 other fish, and might be able to reproduce in certain conditions. Nature has it's own way of deciding if cross breeding has gone far enough.