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Ryukin Goldfish

By Billy Tai

The history of the Ryukin is somewhat contested. Some believe that it was originally developed in China and further developed in Japan while others consider it a purely Japanese breed. Either way, the history books have it written that the Ryukin arrived in Japan through the Ryukyu Islands, which lies between Taiwan and Japan, in around the 1770s. It is from this region that the Ryukin derives its name. It is also known as the Liukiu Goldfish, Nagasaki Goldfish.

“The term ryukin is derived from Ryukyu, the Japanese rendering of the Chinese Liukiu or Loochoo, the name of the extensive group of islands lying between Formosa and the mainland of Japan; and doubtless indicates the origin of this variety or at least the route by which it entered Japan.” - Excerpt from Japanese Goldfish, Their Varieties and Cultivation by Hugh M. Smith, circa 1909.

Since that time, the Ryukin has been continuously refined and other forms and colors have been recently developed. The Chinese breeders have been at the forefront of developing most of these new varieties - Short-tail Ryukin, Butterfly or Broad-tail Ryukins, all in various new colour forms. Countries like Thailand and Singapore have also started to make steady strides with what is believed to be predominantly Japanese stock.

The Ryukins of Japanese origin are still some of the best examples of the breed and the current archetype of the fish comes from this example. Surprisingly, the characteristic high hump had only been associated with the breed for perhaps only the last 20-60 years based on available photographic evidence of fish in goldfish publications.

Regardless of where the Ryukin’s origin, it enjoys international interest wherever it goes.

I will endeavor to share some understanding of how the Ryukin has evolved into the multifaceted fish that is currently available and discuss issues surrounding the breed’s standards. I will also address how to care, select, breed and groom these wonderful fish.


The Japanese and Chinese use ‘criteria’ or defining characteristics for how to select better fish. Often times, issues with breed conformity become interim standards such as when the Chinese developed the Short-tail and Broad-tail Ryukins in various new color varieties. The heads of these newer varieties often seemed far too rounded or showed signs of head growth. They were invariably created with crosses; the resulting outcrosses infused other features in these fish. These forms may not be acceptable to the Ryukin purest so further refinement is only compelled by market demands. Acceptable standards often become the driving force to manipulate change as the preferences of the masses become entrenched. It is this force that results in fish farmers wanting to improve the heads of these newer varieties. Better fish have started to show up recently. If the masses do not favor these changes, the interim standard does not need to change and new variety is born. I recall a time, when Calico Ryukins with quality humps were rare and this was acceptable at the time.

In the West we tend to fuss over what is or should be a standard for a goldfish breed. This standard could be currently achievable or not. Goldfish standards are problematic as they are hard to pin down and even harder to change once they are agreed upon. At current, the British societies are still trying to settle on a precise standard for the Ryukin. The problem stems from this variety having sub-varieties of acceptable finnage and color. In other words, there are different varieties all definable by the term ‘Ryukin’.

As for the United States, different clubs utilize different methods to judge Ryukins. Many give a general description or a ‘type test’ and use a point system to assess each fish. As I personally do not tend to show fish in my collection, I will leave the standards to each club as there are far too many nuances to explain here.

Current twin tailed Ryukin varieties include:

Standard Ryukin also known as Long-finned Ryukin – The tail is greater that ½ the body length and can be up to twice the length of the body in some individuals. It is also called the Ribbon tail or Fringe tail (a broad lobed tail which differentiates this fish from the tail of the standard fantail).

Broad-tailed Ryukin also known as Butterfly Ryukin – This fish should not be confused with the fish above because it is really a butterfly tailed fish created by Chinese breeders. Tung Hoi Aquarium Co. claims to have introduced this variety in 2003. The dorsal fins on these fish are elongated almost like the dorsal of a Veil Tail goldfish. In Japan and Thailand these fish are called Chochokin.

Short-tailed Ryukin – All fins are shorter compared to the standard Ryukin (tail is less than ½ the body length); another Chinese variety that has become very popular recently especially in Asia.

Currently single tailed Ryukin varieties include:

Tamasaba A single tailed Ryukin bred only bred in red and white. This fish was developed in Yamagata Prefecture of Northern Japan. The tail of the Tamasaba is similar to a comet goldfish.

Ryukins come in the following colors:

  • Red

  • White

  • Calico or nacreous (various types - typically with blue/white base with red, orange, black, brown blotches of color – the more defined the color without bleeding the better)

  • Brown or Chocolate

  • Blue

  • Lavender Purple

  • Olive or Green (wild coloration) including mock metallic

  • Black

  • Lutino Yellow with red eyes

  • Albino

  • Matt

  • Colored matt/pseudo matt

  • Any combination of the above

In addition, there are some proprietary names given to certain color schemes. These include names such as:

  • Tri-Color (red, white, & black)

  • Ginrin (silvery net like scale blue/grey base with orange patches)

  • Sakura (looks matt with red & white but is actually a calico fish as it has brocaded scales)

  • Apache (red & black)

  • Tiger (orange with black stripes)

  • Red Capped or Tancho (body may be any color but has a distinct red tancho marking on the top of the head)

  • Deer – (white fish with partially red scalloped scales) - each scale is red except the outer side which is white

If I have missed any colors, this fish is probably available in that as well or breeders will be sure to create it in short order.

A Ryukin should have a pointed triangular head (zero head growth except in very old individuals) with a pronounced hump that begins right at the base of the head. This is the special characteristic of the Ryukin. This feature is reminiscent of the shape mature male pink salmon take on during their spawning run. Opinions differ on the precise look of the head but I personally prefer heads that are almost flat from the top giving the fish an aggressive look. The head should be no greater than 1/3 of the total body length. The hump should rise sharply from the base of the head in an arching semi-circle shape. The dorsal should attach before the apex and should cover 2/3 of the back. Optimally, the dorsal should be held straight up but some Broad-tail dorsals tend to droop with age. All fins should be paired, symmetrical from both sides, and have no folds or kinks.

Contrary to popular belief, the spine of the Ryukin is not humped but straight. Another misconception is that the shoulder/back of the Ryukin is mainly fatty deposits. This is not the case. The dorsal region is entirely made up of muscular tissue.

The Ryukin should have a well matched belly making the fish seem almost circular from the side. In some instances, the Ryukin’s body may even be taller than it is long. Their muscular broad backs appear tear drop shaped from the front or back resembling the keel of a roman helmet in good specimens. A good belly is required for the fish to deport correctly ensuring that the fish has sufficient ballast to balance and swim with grace.

The best fish currently available (in my opinion) are Thai Ryukins that have Japanese blood lines. The reason for this is two fold. First, these fish are far less costly to obtain compared to Japanese fish. Second, they not only have the huge humps but also the correct head shape that a Ryukin should have. The Thai fish also have some of the tallest dorsal fins that I have ever seen and they are always held straight up.

I have heard anecdotally that the Japanese breeders send many of their best fish to Thailand and Singapore to grow out and then ship the best fish back to Japan and other wealthy European markets like Germany and the Czech Republic to be sold as Japanese fish.


The Ryukin is primarily bred to be viewed from the side making it not as attractive in garden ponds. It is the glass aquarium where the Ryukin truly shines. It is believed that the Chinese developed the Broad-tailed and Short-tailed Ryukins to be viewed from either vantage point. They do require lots of swimming space and water due to their size and high metabolic rate so large tanks are required. A 35 US gallon tank would be considered the bare minimum for a single large ryukin with 40-50 gallons being the preferred. I house my breeders in a 180 gallon tank (6 feet long by 2 feet wide by 2 feet tall).

Culling and Grooming

The Ryukin is not difficult to keep and is generally a very hardy fish. Growing quality fish to standard starts with the selection of good specimens. Good conformity alone does not guarantee show quality adults. They will not develop to their potential if they are not fed properly and in the right amounts. In addition, the maintenance of clean water with zero nitrates and ample swimming space are the keys to success. Experiment with the use of hardy plants and the growth of algae to assist with this.

Free swimming Ryukin fry can be fed standard fair for all breeds of goldfish. If you are old-school, you can use hard boiled egg yolk squeezed through a cheese cloth but newly hatched brine shrimp for most breeders is the norm. I have personally used Hikari frozen baby brine shrimp and Hikari First Bites with great success. The Hikari fry food is a powder and can be easily placed in automatic timers for concise regularly timed feedings when you cannot always be around to do it personally.

Once off baby brine shrimp, Ryukins are best fed high-protein pelleted foods to accelerate the growth of the body and improve the hump. Use whatever pellet fits into the fish’s mouth and continue to change pellet size as the fish grows for success if you want to maintain and improve the body conformation. Supplement the feedings with frozen blood worms, daphnia (water fleas), mosquito larvae, steamed rice, hulled peas, and various other food stuffs.

I normally reduce the protein content of the feed to my adults unless I am trying to condition them for spawning. I use a lot of wheat germ based foods typical of spring and fall feed formulas to ensure that my fish are properly filled out.

Water depth for rearing and raising Ryukins should never be too deep as this encourages elongation of the body. I suggest the depth should never exceed two feet. Most of the Chinese and Japanese rearing ponds are within this depth. Ensure that there isn’t excessive current generated by filtration as fish forced to swim constantly burn off precious calories that could have gone into growth.

Culling takes place as soon as the Fry are free swimming. Remove any fish with obvious deformities. Crooked backs and belly siders are usually the only things to initially look for. Since it takes some time for the tails to show up, I do not start culling for tails until the fish is approximately an inch long. I cull for asymmetrical tails where one lobe is smaller than the other. If the fish shows good body conformation I will not cull for undivided tails until the fish are approximately 1-2 inches in total length. A proper Ryukin tail should be held high (30-45 degrees from the peduncle). The overall spread of tail when viewed from the side should be ideally 90 degrees from the leading ray of the upper lobe and the leading ray of the lower lobe and appear triangular from the back with the lower lobes spread outwards also at approximately 30-45 degrees. Tails that are parallel are not desirable and hinder the ability of the fish to swim properly. The Broad-tail has the most splayed tail and leaves the peduncle with a more horizontal angle so selection will depend on what variety you are working with.

I personally strive for what appears to be the tail of a classic Bristol Shubunkin. The lobes of the tails should be broad and not fantail or ribbon-tailed shaped. I believe that fish with these tails are acceptable but are inferior and do not represent the advancements in the breed to a broader lobed fish. Culling is predominately done from the side unless you are looking for divided tails which should be done from above. All fins should be paired, straight, and evenly matched with the exception of the dorsal that should always be held high. Double anal fins are preferred but fish with a single anal is also acceptable as long as its placement is in the centre of the body. The lower lobe of the tail should mask the anal when the fish is viewed from the side.

The classic hump of the Ryukin will show up when the fish is approximately 2-3 months old. The hump can be fully developed by the time the fish is only 11/2-2 inches long. I have seen YouTube videos of Ryukins where the fish develops a hump even younger, but I do not feel that these are superior quality fish. It just shows that proper grooming makes a huge difference in the outcome of the adult fish.

I will usually also cull for head shape at 2-3 months of age. Ryukins should have a pointed head with no mouth deformities. Heads with rounded appearance and mouth deformities can be easily distinguished at this size and discarded. The head should be the shape of an equilateral triangle.

A common flaw with Ryukins is curled operculum. Often it is the membrane of the operculum that curls outward but sometimes the gill cover also curls. If the fish has superb physiology otherwise, you can perform surgery on the fish to correct the problem. Use curved nail scissors to carefully remove the outer part of the gill plate. The gill cover will usually grow back straight with a membrane that lies flat against the fish’s body. Make no mistake, this is a flaw and a fish with this deformity should never be used for breeding or sold for breeding stock.

Fish with cut gill or part of their operculum missing should be discarded. It is the belief of some in the goldfish community that this genetic flaw is the result of too much inbreeding and an immediate outcross is necessary.

Many collectors will only feed sinking pellets, but I use both floating and sinking pellets to encourage the fish to forage at all levels. Swim bladder issues are usually, in my experience, directly linked to excessive nitrates. The only exception is periodically when a female Ryukin gets egg bound and will lie either on her side or upside down at the bottom of the tank. I have rarely had fish develop buoyancy issues after I moved to a large water change regimen years ago. I usually perform 90% water changes weekly on all fish over 2 months of age. Fry get 25%-30% water changes every other day.


Ryukins are prolific breeders. Male Ryukins are hard chasers and will often damage females if left to spawn naturally in aquaria. If you chose to spawn your fish naturally you can avoid damaging prized females if you are spawning fish in ponds or large aquariums with sufficient space. Hand strip prized fish to avoid injury after the spawning chase has begun. I will only hand spawn after the fish are allowed to chase naturally but I will also allow fish to breed naturally if I am able to keep an eye on them. I usually use the milt of 2-3 males for each female depending on their size. Strip the male first and then the female second making sure to swirl the eggs to ensure that eggs do not clump and stick together. If the eggs clump together they will not develop and will fungus.

Here are some pictures of my spawns from previous years. The fish on the right is a young Ginrin Ryukin.


The Ryukin is considered one of the hardiest varieties of goldfish and is the only variety of goldfish known to have possible aggression issues towards other goldfish. I once had a Thai Ryukin that had to be housed alone because he would shred the fins of all the fish in his tank, male or female and he didn’t even show breeding tubercles.

Ryukins are winter hardy but in my experience they do not handle extremely cold water well. Most Ryukins will lie motionless on their sides during extreme cold conditions subjecting them to possible septicemia infection during spring. If you chose to house your Ryukins outside, introduce your fish to the pond early in the season to ensure that they have acclimated to the outdoors. Ensure that they have been well fed throughout the season so they have saved up enough fat stores to last them the winter under ice.


The Ryukin is a striking variety that is both robust and beautiful. With the array of finnage options, and color varieties to rival any goldfish, it will appeal to collectors, breeders and those interested in the show bench. It is no coincidence that this breed often wins best in show as compared to other breeds. As luck would have it, it is also a variety that is one of the easier breeds to keep so remains within reach of beginners through to the most advanced and dedicated of hobbyists.

*All photos in this article are fish owned and/or bred by Billy Tai

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1 commentaire

Such a good article.

Boooo to standards 👎🏻

The real interesting work comes from cultivators bringing new life to lines in terms of vigor, new coloration, new scale types

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