Koi and Goldfish are two popular fish species which are the choice pets for enthusiastic fish keepers, who want to liven up their pond life with a variety of beautiful and charming aquatic fauna.

While both species offer a lot of excitement and pet keeping fun, some amateur pet owners find it hard to distinguish both types of carps from each other. It is a regular problem which every novice fish owner can face. The key to ensure that one learns the differences between the two species is to make sure that one engages in some research work, to have some knowledge about the pets they plan to keep.

There are some easily distinguishable differences between the Koi and the Goldfish, which make it possible for every aspiring fish owner, to effortlessly differentiate between the two species.

Size

This is the most obviously discernible feature of both the fish species, which makes it possible for everyone to easily distinguish between the Koi and the Goldfish, at a glance. Any colorful fish which is longer than 15 inches is bound to be a Koi.

Fish experts state Goldfish to reach a maximum size of 32 cm, while Koi are reported to be 110 cm long. Young fish are harder to distinguish.

Barbels Or Whiskers

Koi have barbels on their face, which are also called whiskers. Goldfish do not have this physical feature, which makes it an easy distinguishing factor.

Variety Of Colors

Goldfish are found in a variety of colors ranging from the popular orange, to red, yellow, white, blue, and even black. Combinations of red and black, or white and black are also found but very rarely. Red and white is a more commonly found combination.

Compared to the Goldfish, Koi is available in a larger variety of attractive color combinations. Red, black, orange, yellow, blue serve as base colors, and there are a mixture of combinations.

Tail  

Both the species have long and elongated tails, but the Goldfish has a double tail, which projects a three or four pronged appearance, when viewed from above. The double fin feature is a characteristic physical trait of the Goldfish, which is not found in Koi.   

By knowing your aquatic pets from each other, you can enjoy and draw comfort from the relaxing hobby of keeping both Koi and Goldfish as pets in your pond.