The goldfish (Carassius auratus) is a species of freshwater fish in the carp and minnow family Cyprinidae. It is indigenous to southern China, where it was first domesticated during the early first millennium CE. In nature, these fish tend to be silver, but can sometimes be red, yellow, or orange; these more colorful varieties were bred for their appealing hues and were favored by imperial families for more than a thousand years. Today they have become extremely common after being imported to Europe in 1611. Many different breeds exist. In aquariums they usually only grow a few inches in length, but can easily grow to a foot or more in the wild. They are among the most common aquarium fish in the world due to being readily available, fairly inexpensive, and highly omnivorous; despite this, many people do not know how to properly care for them, and they are often released into the wild. Because of this they have become an invasive species in North America and Australia. They are considered a species of least concern by the International Union for Conservation of Nature, with their strong adaptability protecting them from most threats to their survival. They can decimate ecosystems in which they are not native.
