Koi Varieties - Chagoi

Welcome to our newest instalment of our ‘Koi Varieties’ series where today we will be looking at the Chagoi koi, one of the oldest varieties of koi carp.


Chagoi koi from breeder Yamazaki

The Chagoi (CHAH-goy) koi, literally translating to ‘brown carp’ are an old variety of koi that look very similar to the wild carp. The word 'Cha' meaning brown comes from the word 'Ocha' which means tea and these koi were originally named Ochagoi due to their resemblance to the brown tea colour. Very quickly, however, the 'O' was dropped as the farmers put emphasis on the 'chah' sound, leaving us with the name we are all familiar with today. The Chagoi koi are typically referred to as the ’gentle giant’ as they tend to grow much bigger than other koi varieties and are very docile around people. They will typically come and greet you at the top of the pond, be willing to be touched, and will often encourage other koi in the pond to be more friendly.


Many Chagoi koi, but not all, also have a reticulation pattern in their scales. Some koi keepers prefer the Chagoi to be a bit more interesting while others prefer to keep the variety natural and as similar to the wild version as possible. Therefore, both versions are still popular and therefore bred. This reticulation pattern is called fukurin (FOO-koo-REEN) and gives the fish a net-like appearance with each scale having a darker border.


History of Chagoi


Chagoi koi were first bred in the Taisho Era (the period from 1912 to 1926 when Emperor Taisho controlled Japan). These koi were different from the many other varieties of ornamental carp as they were not bred specifically to create a variety of koi, or for a particular colour, pattern or even skin type. Instead, Chagoi were created accidentally from selectively breeding traits in the common carp that made them more valuable as food and easier to keep. That is, they bred the fish to be big as well as tame and friendly. With each new generation of Magoi (common carp), the farmers chose to grow on and breed only the biggest, friendliest fish and within only a few generations, the majority of fish born were lovely and tame. At this point, their colours had changed a little and they were significantly different from the wild Magoi in both size and temperament that they were often kept as pets and even sold as pets rather than as food. It was at this point that the variety was formally named the Chagoi.


As the years passed and more varieties were developed, it became clear that the breeding methods used to stabilise the varieties were having a negative effect on the size of the koi and the rate of growth. Koi that were significantly different from the wild koi, such as Doitsu koi, typically grew a lot slower and rarely reached the same size as Chagoi koi. Even today, almost all the prizes for the largest koi go to Chagoi koi and the variety has the largest percentage of Jumbo koi (koi from a good bloodline of larger fish).



Gin Rin Chagoi koi from breeder Otsuka

Pongoi (Best Quality) Chagoi


When it comes to judging a Chagoi koi, the most important consideration is the consistency of the colour. Since the Chagoi do not have the bright colours and patterns of other koi varieties, the base colour is very important as it is the only thing that can be judged. The more consistent the colour of the koi, the better the quality of the Chagoi. The cha (brown) should be the same shade over the head, down the body, through the fins and in the tail. Any deviation in shade is considered an imperfection in the fish. Of course, the shade of the cha is important too. The darker, mud-like brown is less appealing in a Chagoi and, instead, the paler the brown, the more desirable and, therefore, valuable, the Chagoi is.


If the Chagoi koi has the fukurin pattern in its scales, these should be as even as possible. Each scale should be arranged neatly and in even rows and the thickness of the reticulation should be equal across all the scales. While it is not so important exactly what colour the fukurin is, it is important that it is even and a consistent colour over the whole fish.


Because of their renowned friendliness, this should also be considered when choosing a koi, and it is indeed considered at many koi shows. The Chagoi that comes straight to you should be preferred over any other Chagoi who hang back or show less personality.


Finally, because one of the main draws of Chagoi are their size and they are otherwise one of the simpler koi varieties, the body shape of the koi is incredibly important. For more information on what to look for her, have a look at our blog post ‘Koi Varieties – What to Look for When Buying a Koi'.



The main draw of Chagoi koi for most koi keepers is their friendliness and tame personality. In a pond with many different varieties of koi, it will be the Chagoi who will always come and greet you. They may not be the quickest moving koi, but they will always come to the top of the pond when they see you and they are often very accepting of a pat or a rub. Their confidence around you and their willingness to be touched will also rub off on the other fish in the pond. When they see the Chagoi going to greet you with confidence, they will see that it is safe and will often also come to greet you! In fact, many koi keepers add a Chagoi to their pond purely to improve the confidence of the other fish in the pond.


Chagoi koi with strong Fukurin from breeder Okawa

However, their friendliness and tameness are not entirely because of the selective breeding when the variety was first established. The Chagoi koi were never bred for bright colours and patterns like other koi varieties, instead have been bred to look very similar to the wild carp. As they have not been bred too far away from the wild version, they typically grow bigger and quicker than other varieties of koi whose growth has been slightly stinted due to the selective breeding for pattern rather than for size. Since the Chagoi koi are typically larger than other koi, they are often hungrier and are always alert for food. This results in the behaviours often seen as friendliness, such as coming to the surface when they see you. Of course, this doesn’t mean that Chagoi are not actually friendly, it is just a combination of their tameness, hunger, and increased confidence due to size that causes these behaviours.



Chagoi are a great addition to any pond with their confidence and influence on the other fish in their pond. Not only that, but they are such great growers that with a good diet, you can almost see them grow and each year will bring a considerable change in the size of the fish!


To have a browse through our current selection of Chagoi koi, click here:


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