Turns out, goldfish are one of the world's worst invasive species. Goldfish were first ... but in the wild it's a different story. Given enough time and resources, these little orange monsters ...

Goldfish also breed quickly, and since they don't have natural predators in most North American waters, their populations can "explode," the U.S. Fish and Wildlife Service says. "By making good ...

In fact, goldfish are actually an incredibly diverse, hardy, and large species of fish that can live quite a long time. There are also many different varieties to choose from, making them ideal ...