I found a Dace (minnow) in my pond of goldfish! No clue as to how it got there. It was tiny, but has grown to about 1.5" at last look. Was definitely not a goldfish. It had a blue stripe and everything! I think they grow to 4".
My goldfish have spawned and there are dozens of fish fry swimming around. I havent spotted the Dace in a few weeks. There is also a couple of resident Leopard Frogs that live in the pond. Only the strong fry survive, right? The Dace might not have made it.