Ranchu goldfish is a very popular choice among many fish keepers all around the globe. If there is a goldfish enthusiast out there, he/she will definitely have a Ranchu goldfish.

These species were developed from Lionhead Goldfish, specifically bred to have no dorsal fins. The difference is the Lionhead has a bigger wen and a less round body than the Ranchu.

This has led to a weaker resistance overall than its relatives. But, do not let this dampen your enthusiasm. If proper care is taken, they can prove to be better pets than other goldfish varieties.

The article covers all the details that you must require to care for your Ranchu goldfish, even if you have no experience with them.

Cute Ranchu Goldfish Care Guide
Cute Ranchu Goldfish Care Guide

A Brief Review of the Species

Quick Species Facts
Scientific Name Carassius auratus auratus
Other Common Names King of Goldfish, Maruko, Buffalo-head Goldfish, Egg-Shaped Goldfish
Family Cyprinidae
Origin China
Average Lifespan 12-15 years
Average Length 12.7-13.0 cm
Type Freshwater; Slight Tolerance for Brackish water

Origin & Distribution

Ranchu, which was a popular Fancy Goldfish variety, was first found in the regions of China and Central Asia (Siberia) but was later developed for the market in Japan, in the late 1800s.

They are freshwater fish but have a slight tolerance for brackish water as well. They inhabit freshwater bodies such as ponds, groundwater ditches, lakes, and slow-moving or stagnant rivers.

How do Big Do Ranchu Goldfish get?

Ranchu can get quite big and plump. They grow to an average size of 5- 5.5 inches. But it is not uncommon for them to get bigger.

bigger Jumbo Ranchu Goldfish
Jumbo Ranchu Goldfish Care

They can attain a size of 7.5 to 8 inches when good care is taken by aquarists. These bigger ones are referred to as Jumbo Ranchu Goldfish.

It has also been reported in a paper that some goldfish managed to achieve a length of 48 cm in captivity.

Read here – Biggest Goldfish – How Big Can Goldfish Get?

What do Ranchu Goldfish look Like?

Morphological Features

  • Ranchu Goldfish bodies have an egg-shaped appearance with a very curved spine. Their bellies are very round and constitute approximately 5/8th of their body size.
  • They have two pairs of visible fins underneath their bodies- pectoral and ventral. They also have a pair of anal fins, which are less noticeable and seem to be fused with the caudal fins. They do not possess a dorsal fin, not even a vestigial one.
  • Their caudal peduncle (stem of caudal fins) makes a steep angle of 45° with the body and tail. The caudal fins are short and round and comprise two to three lobes. These caudal fins also come in a pair.
  • They have a bulbous, fleshy growth that covers their head and cheeks, known as the Wen. They develop notoriously with age, which can sometimes cause them to grow over the eyes, partially disrupting the vision of the fish.

Colors Varieties in Ranchu Goldfish

  • Interestingly, you can discover a variety of hues like orange, reddish-orange, and golden-orange.  White Ranchu Goldfish are somewhat uncommon but the blue, brown, and pale yellow are comparatively rarer.
White ranchu goldfish care - Colors Varieties in Ranchu Goldfish
White Ranchu Goldfish Care
  • Some even come with patchy textures with color combinations of orange-white, red-white, black-white, and white-orange-black. The black-white ones are often called Cow Ranchu Goldfish because their color patterns are similar to cows.
Cow Ranchu Goldfish Care
Cow Ranchu Goldfish Care
  • A highly demanded variety is the Black Ranchu Goldfish. They are very expensive, and kind of rare also. As you can tell by the name, their whole body is black in color which makes them very appealing.
Black Ranchu Goldfish Care
Black Ranchu Goldfish Care
  • Their scales can be lustrous, matte, or calico (nacreous).

Lionhead Ranchu Goldfish

Also known as Lionchu, is a cross between a Lionhead and a Ranchu goldfish. They have the larger wen of the Lionhead and the rounder curvature of the Ranchu, along with the signature dorsal fin-less body.

How Long Do Ranchu Goldfish Live?

Fancy Goldfish – Ranchu

In the wild, Ranchu goldfish can have an average life span of about 10 to 15 years, which is quite average for a big species like this.

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In captivity, however, they can grow up to the age of 20 years. They might even be able to top that because goldfish in general can live for a long time.

There is a paper that mentions a particular goldfish that achieved the astounding age of 41 years.

Quick Tip: You can estimate the age of a Ranchu by looking at its wen. The bigger it is, the older the fish.

How to tell if it’s a male or a female?

It is kind of difficult to differentiate between a male and a female Ranchu Goldfish just by their appearances. They both look strikingly similar.

They both have stubby, round bodies. But during spawning, the female gains a little more plumpness than the male Ranchu because she carries eggs.

Moreover, male fish seem to be slightly thinner in general, but only by a very small margin, barely noticeable.

The males, however, during the breeding season, develop tiny tubercles (small white prickles) on their gill operculum (cover) and head. This feature can be used to differentiate, but it is effective only during the mating season.

Sale Price of Ranchu Goldfish?

These are widely available worldwide in most shops. The common orange-white is sold for at least $5 to $10. Some rarer ones are sold for $200 and up.

It all depends upon the color and size of the wen. The Black, Blue, and Pale yellow with red wen ones can go for an average price of $50 and Calico Ranchu can be around $40 approximately.

Complete Care Guide

Quick Care Facts
Care Level Moderate
Breeding Easy; Scattered Egg Layers
Social Temperament Peaceful; Friendly
Diet Omnivorous
Hardiness Low

Best Food for Ranchu Goldfish

As an omnivore, like all other goldfish, they eat all kinds of fish food. I would advise feeding them live food to maintain good health overall.

A few examples are as follows-

  1. Fish Flakes (low- and high quality)
  2. Fish pellets
  3. Frozen meaty food
  4. Worms- Bloodworms, Tubifex, Mealworms, Wax worms
  5. Brine shrimps (live or frozen)
  6. Planktonic crustaceans- Artemia, Daphnia
  7. Vegetables (Raw or Blanched)- Carrot, Plantains, Lettuce, Broccoli, etc.

For the proper development of Wen, protein should be an important part of their diet. So, try to incorporate protein-rich food along with vegetables for a well-balanced diet.

It is advisable to feed them Tubifex worms every few days. They are a very good source of protein, and the fish love eating them. It is like a treat for them.

Author Note: They are a bit lethargic, so they eat slowly. Therefore, there is a chance to overfeed them if you don’t pay attention to the time.

Are Ranchu Goldfish Aggressive?

Ranchu Goldfish are very social and friendly fish species. Just like other goldfish, they like to live in groups. The bigger it is, the happier they are.

They have no aggression towards any other fish. The only exception would be another male Ranchu. If two males are kept by themselves, they will fight till one of them is badly injured.

However, this can be avoided if females are kept with them in a group. Generally, the number of females is kept higher than the number of males to keep a peaceful and happy environment.

Ranchu Goldfish are lazy and they move quite slowly around the tank. This could be due to their big, heavy body and inadequate quantity of fins.

One feature that makes Ranchus a widely demanded pet is that they can recognize their owners. However, there is no proven evidence but their behavior says so. They get quite excited when they see their owners.

They are also benthopelagic, i.e They are bottom feeders as well as swim in the middle section of the tank and occasionally near the surface.

How Do They Breed?

In the wild, the breeding time for them is usually around the spring season. So, you rely on the natural weather or change the temperature of the water to induce breeding. It is best to follow the natural clock for breeding.

Spawning of eggs

The female needs to have access to low-temperature water to induce egg formation. The temperature should be maintained at around 10-12 °C for a few days.

Then it should be gradually increased by 2-3 degrees every day till they show spawning activity. During this period, the temperature should be maintained at around 22-24 °C, where the most spawning is seen.

The male Ranchu will generally bump the female on her side to release eggs. Sometimes it may get too rough for the female, so try to keep the male away if things get aggressive. Ranchu breeders like to put a wall in the tank between the two.

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The female Ranchu Goldfish will lay around 8,000 to 10,000 eggs on flat surfaces or leaf blades. After which the male will spray his milt all over them to fertilize.

Rearing of Baby Ranchu Goldfish

The eggs take about 5 days to a week to hatch. The juvenile fry does not resemble tiny Ranchu at all. It takes a few weeks for them to develop morphological features like their parents.

The babies should be fed protein-rich foods and softened vegetables so that they have all the beneficial nutrients required for healthy growth.

They have dark coloration, which helps with camouflage and protects them from predators.

The juveniles can be safely put with their parents when they have attained the size of 1 to 1.5 inches. At this point, the parents will be able to recognize them as their babies.

Pro Tip: The parents can sometimes eat the eggs and even their sac-fry. So, it’s better to transfer them away for a while till the eggs hatch and the babies develop some adult features.

Common Diseases

Ranchu goldfish are not considered hardy like other goldfish species. They are heavily inbred, so their natural immune system is somewhat lowered. You have to be extra careful when keeping them.

As part of the freshwater fish family, they can suffer from all kinds of freshwater diseases, and their treatment is the same as how you would treat an average goldfish.

Dropsy is a disease that is very common in goldfish. It makes them fatter than they already are. It is a fatal disease and is considered irreversible because it is very difficult to recover from it. It can be caused by a bacterial infection or kidney failure.

Read in detail about Dropsy fish disease

You should also keep an eye out for protozoa such as Ichthyophthirius multifiliis or commonly, Ich. It causes tiny white spots (1mm in size) to appear all over the body. This can be treated with antibiotics but is life-threatening if left untreated.

There are also other parasites such as Costia and Chilodonella which cause a cloudy appearance on the skin. Antibiotics and salt baths can be used to treat them.

Some skin flukes can also be fatal to the Ranchu if not treated in time. Anchor worms can attach themselves to the body of the fish using tiny hooks in their mouth. They appear like threads attached to the fish.

It is always recommended to move the fish into a separate tank for treatment as soon as you see any irregular behavior or changes in its general appearance.

Ranchu Goldfish tank size and water parameters
Ranchu Goldfish Tank Parameters

Tank Recommendations

Quick Tank Facts
Water Temperature 65.0 to 72.0° F
Minimum Tank Size 10 gal
Water Hardness 5 – 19 dGH
pH Level 6.0 – 8.0
Nitrate Content < 40 ppm
Max Salinity/ Specific Gravity (optional) < 1.002

Tank Size & Shape

Even though they are big, they can be kept in small tanks. This is another advantage of having them as pets if you are on a tight budget.

But the tank should not be less than 38-40 liters, as they also need space to swim around and not feel cramped. An ideal volume for one single individual would be 70-80 liters. And if you want to keep a group of 5-6 fish then you should get at least a 190-200 liter tank.

For the shape of your tank, you can use any type as long as it is not tall. Try to get a long tank with more surface area so it offers more oxygen dissolution in the water.

Many fish keepers like to use spherical or oval tanks for their goldfish because it looks good but it has a smaller surface area.

What to Include When Setting Up a Tank


Plants are necessary for the goldfish. It provides natural oxygen, and Ranchu goldfish require a lot of oxygen. So, it’s a good idea to plant natural foliage rather than artificial ones.

Regardless of the advantages of having natural vegetation, these species like to dig into the substrate, which can sometimes lead to the uprooting of plants. So, in this game, having a few artificial plants might be a good idea.

A few plants suggested for the tank are-

  1. Amazon sword
  2. Miramar Weed
  3. Hornwort
  4. Water Wisteria
  5. Anacharis
  6. Water sprite
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Pro Tip: Avoid using plastic plants because they can harm the goldfish as they have poor eyesight. You can rather go for silk ones as they are soft and won’t cause any damage even if the goldfish decide to fiddle with them.


For lighting purposes, mediocre lighting should be enough. It is only a matter of preference when it comes to what kind of light you would like to install.

Some like bright lighting to bring out the colors of the Ranchu. But be careful of using strong light as it can increase the water temperature, even by a small margin. Ranchu goldfish prefer cooler temperatures.


Try to avoid a small gravelly substrate for your tank. These fish like to dig around and scavenge for food particles along the substrate.

They might accidentally ingest small pieces of gravel while scavenging, which can lead to death if not detected. Sometimes it can even get stuck in their mouth.

So, it is better to use large-sized pebbles or sandy substrates viz White sand or Aragonite sand to adorn the tank. Some people like to use bare bottom tanks, but that’s not advisable.


All kinds of décor can be used, whether natural or artificial, as long as they don’t have sharp pieces sticking out. Ranchu goldfish occasionally bump on the decorations by accident because of their bad eyesight.

Big rocks with holes and large hollow logs of wood can be a good choice. It provides a place to rest or hide for the fish babies.

Decorations with flat surfaces like flat rocks can also be useful during the breeding season. They provide a suitable place for the goldfish to lay their eggs.

Tank apparatus

Having efficient tank filters is a good idea. Ranchu goldfish eat a lot and produce large amounts of waste while having low nitrogen tolerance. So, having good filters eliminates this problem.

Another useful apparatus would be having bubbling Aim pumps. These ensure the water is always rich in oxygen. Airstones can also serve a similar purpose.

Water Parameters

If you want to keep your goldfish healthy and happy, you have to maintain specific parameters for the tank.

  • Goldfish like cool temperatures, especially during mating hours. So, try to maintain a temperature between 18.3 to 22.2° C.
  • Keep the water soft, and maintain the hardness between 5 – 9 dGH.
  • For pH, keep the rating between 6.0 to 8.0. They can tolerate changes in the pH but try to keep it neutral or slightly alkaline.
  • Do not, in any case, let the nitrate concentration go over 40 ppm. It is very easy to spike the nitrogen levels in the water because of their diet.
  • If you are keeping them in a brackish environment, the salinity should not go above 1.002.

Suitable Tank Mates

They get along well with most fishes, since they are peaceful in nature. You might want to keep them away from aggressive fishes such as Cichlids, Oscars, etc.

Also, try to avoid fin-nippers like Tetras, Barbs, Redtail sharks, etc., as they might damage the fins of slow-moving Ranchu.

Algae eaters such as Plecos or Chinese algae eaters aren’t good for them because they occasionally attach themselves to their bodies and suck on the slime they produce.

A few compatible companions for the Ranchu are given below-

  1. Other Goldfish varieties
  2. Kois
  3. Weather Loaches
  4. Mollies
  5. Guppies
  6. Zebra Danios
  7. Cory Catfish
  8. Swordtail
  9. Livebearers

Frequently Asked Questions

Are Ranchu goldfish easy to take care of?

They have similar tank requirements as any other goldfish, but they are less hardy. So, one must be extra careful while keeping them and ensure the environment is kept as hygienic as possible. So, we can say they are somewhat easy to take care of.

How to groom Ranchu goldfish?

Maintaining a nutrient-rich diet and keeping the waters free from murk is a good step toward grooming. Alongside it, changing and replenishing 80-100% of the water can prove to be excellent for the health of the Ranchu.

Where can I get a Ranchu goldfish?

Ranchu goldfish are found all over the world and are available in most local markets. You can also find them online, but shipping charges may vary from country to country.

Why is Ranchu the King of Goldfish?

People say that they symbolize harmony and the culture of Japan. Ranchu resembles the physique of Sumo wrestlers, with their large heads and extremely round bodies. And that is the reason why it has been given the title of ‘King of Goldfish’.

Can Ranchu goldfish live alone?

They can be kept alone in a tank if they get enough food and swimming space, just like other goldfish. But they are naturally social creatures, so they live happier in a group rather than solo.

Final Thoughts: Should We Get Them?

If you love goldfish in general, then you will definitely love them. There is a reason why they are referred to as King of Goldfish.

Ranchu goldfish are cute and friendly, which makes them suitable pets for your tank to keep with other fish. Having a good social character is an addition to that.

They even have a tolerance for slightly brackish water. So, it could be a possibility to keep them with other Marine fishes if you can aquascape a hybrid reef tank.

Feeding them isn’t a problem either. Just keep a balanced diet and you will see them live for a long time.

About the Author

Victoria Lamb

Victoria is a freshwater aquatics specialist, fish keeper, and amphibian enthusiast. She has had more than 6 years of experience caring for aquariums and keeping several fish species, and her home boasts of 3 aquariums and a garden pond. Her goal is to educate fish owners on raising healthy and happy aquatic pets. Career Highlights:…

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