What is this fish?

[clark kent]

Up until about a year ago, all I ever saw in my thousand gallon pond was plain old goldfish, maybe about a dozen, from about two inches to four inches long. They come, and they go, depending on predators and new fry. They're all either gold, light pink, or dark gray when they're very small fry.

Now, I see two or three fish about three or four inches long that are dark gray with silver sides. They just don't look like goldfish. They haven't harmed the goldies. In the four years I've had this pond, I've never seen fish like these before.

See the pictures below.

What are they?
How did they get here?

 

[JRS]

Goldfish, just another color variation closer to their natural color, likely babies that grew up. Sometimes they will change colors as they age. I had a natural colored one that changed to all white starting around 4-5 inches.

 

[WaterGardener]

I agree. It's probably a goldfish. It will very likely keep loosing the black as it gets older.

 

[Mmathis]

Goldfish. Many times they start out very dark (which is a camouflage from predators and also why you probably never spotted them before), and then one day they are gold — it almost happens overnight.

 

[Lisak1]

Yup. Goldfish. They may change and then again they may stay that color. We have one that is almost 8 inches long and still dark.

 

[rubyduby]

One of my shubunkins throws these exactly and they never change color...They are real survivors too since they are hard to spot from predators...

 

[addy1]

I have a lot of dark fish!

They survived the snakes.