The Great Pond Debate: Goldfish or Koi?

It’s summer time, so you might be thinking about digging out your own pond while the ground is soft and dry, or you might already have a pond but are thinking about adding a collection of fish to the environment. Either way, you’re the decision of whether to go with goldfish or koi car can be tricky.

Although both species feature striking gold colour – making them the perfect ornamental fish for a garden pond – they’re different in a number of key ways. Here at All Pond Solutions, we want you to be informed before you make your purchase decisions, so here are with that in mind, here are some of the differences between goldfish and koi. Which will you own?

Size Is Everything

Certainly, the most obvious distinction you can make between goldfish and koi carp is in size. If you see two gold coloured fish and you can’t tell whether they’re goldfish or koi carp, check their lengths. If one is over 15 inches, it is certainly a koi.

Even 12 inches might seem a little bit big for a goldfish as most people see them when they are small having been confined to a tank. In a large pond, however, they can grow to much larger sizes. When goldfish are at their largest and koi carp are at an average size, this is where it can be difficult to tell the two species apart by size alone, so you will need to revert to other features of the fish to tell them apart. 

So which is better? Well, it all depends. If you think that the larger the fish, the better it is then koi clearly win out. However, fish only grow to a size appropriate for their environments, so if your pond is only a few meters across, your koi won’t grow much larger than goldfish would, anyway.  


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Differences in Colouration

Probably the second most obvious way to differentiate between a goldfish and a koi carp is through their colouring. Although both goldfish and koi carp are able to come in gold and white speckled combinations, it is commonly known that koi carp are more versatile in the colour offerings.

The general colour offerings for koi are red, white, black, yellow-orange and blue, so as you can see, there’s a lot more scope for colour offerings with koi carp – a real advantage. However, if you’re looking for a classic golden look, the other colours make no difference.        

Lower Bottom Jaw

Now we’re getting into less noticeable features. However, if you have two fish side by side and you still can’t tell the difference between them from the size and colour, there are a few other tell-tale signs. One good one is that koi carp have lower, bottom jaws as they have been selectively bred from common carp, which also have lower bottom jaws. Goldfish, on the other hand have more equal, rounded jaws. It might be a subtle difference, but it’s one nevertheless, and if it comes down to it, you can use it to differentiate. Now, it’s hard to say that jaw placement of either the goldfish or koi makes either one more attractive, but with the low jaw of koi better suited to bottom feeding, it might make more sense to choose goldfish if you want to see your fish feeding up in the water.

Barbels or Not

Finally, one last way to tell the difference between goldfish and koi is that koi have little feelers on the ends of their mouths – called barbels – which goldfish do not. Although these are not necessarily an attractive feature, they are a great marker for identity. If you’re not keen on barbels, however, you might want to stick to goldfish.

So then, what’s the answer? Goldfish or Koi Carp? It seems as though there are pros and cons for both species, so our answer is to get both. After all, variety is the spice of life, and as you now know, there are various sways to differentiate between the two.