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Ranchu Goldfish: Raising the Amazing Fancy Goldfish

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I've owned a black ranchu and a red and white ranchu, and I'm an enthusiast of these incredibly beautiful goldfish.

My very young Ranchu.

My very young Ranchu.

Ranchu Goldfish Care

I am a ranchu goldfish enthusiast, and I'm writing this article for people interested in having ranchu goldfish as pets. I will include some tips on keeping ranchus, common problems, and things to consider when looking into this species of goldfish.

I have two ranchus in a 4-foot tank: a black ranchu and a red and white one, both around one year old.

A cute-looking ranchu. Some say they have puppy faces.

A cute-looking ranchu. Some say they have puppy faces.

Meet the Ranchu

The ranchu is a popular goldfish species and is especially popular in Japan for its unique appearance and resemblance to a small puppy. Ranchus can be very friendly, and some people are actually able to pat their ranchus or even train them to do little tricks. The ranchu goldfish was bred in Japan from different types of lionhead goldfish.

The ranchu has a fat, egg-shaped body, and when it is fully grown, it can look quite strange—but this is the attraction for goldfish enthusiasts. The ranchu also has very beautiful head growths which are prized by goldfish breeders.

Ranchus are friendly, and some allow their owners to pat them!

Ranchus are friendly, and some allow their owners to pat them!

Tank Size and Conditions

Like all goldfish, they require a decent-size tank, and the most important factor when choosing the tank is the surface area of the water. This ensures enough oxygen for your fish. When choosing a tank, a long rectangular tank is preferred over a tall tank.

The ranchu goldfish is a very slow swimmer and because of its body shape, it does not cope with strong currents. Make sure you have a good filter that is not too strong, or point it at a rock or some plants to reduce the strength of the current.

Healthy natural feed for a ranchu: duckweed.

Healthy natural feed for a ranchu: duckweed.

Ranchu Feed

The best thing to feed your ranchu is any type of sinking pellet. It is also beneficial to include easily digestible plant foods such as duckweed, algae, and wheat germ to aid digestion.

For a treat, ranchus enjoy oranges, mandarins, live food, worms, and shrimp. I currently use a specially formulated ranchu food made by Hikari fish food to produce strong, colourful, and healthy ranchu.

Remember that normal rules apply when feeding your goldfish, depending on the temperature. At temperatures above 20°C, the goldfish's digestive system works optimally. At cold temperatures, they will have trouble digesting, and if they eat too much from overfeeding, they can bloat and even struggle to digest the food completely and die. So take care when feeding your ranchu.

Serious bloating issues.

Serious bloating issues.

Common Problems

These are the two issues I've encountered most frequently with ranchus.

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Swim Bladder

The most common ranchu problem I have seen is swim bladder, where the ranchu will swallow too much oxygen and keep floating up to the top of the tank and then eventually flipping over. This condition can be avoided by feeding your ranchu sinking pellets so they don’t have to come up to the water level to get the food. Feeding your ranchu easily digestible food such as duckweed and plants can also help relieve swim bladder problems.

Swallowing Pebbles

The other problem I have seen is that your ranchu may suck on pebbles and often accidentally swallow them, so it's very important to ensure the pebbles in your tank (if you have any) are small enough to pass through the ranchu’s body. Sand could be a great alternative to pebbles and can give your fish tank a nice beachy look.

Ranchus of various colors.

Ranchus of various colors.

Ranchu Prices

When ranchus are fully grown, they can fetch very high prices; for example, a five-year-old purebred ranchu can set you back around $100 US and even higher, depending on the size and vibrant colors of your ranchu. At most pet shops I have looked at, you are able to buy a ranchu for around $20 US for a 6–7 cm one, which is a very reasonable price. Look for a similar price; otherwise, you may be getting ripped off.

Where to Get Your Ranchu

Ranchus are not a very common fish species found in most pet stores, so it may take a bit of fish hunting to find one. If you are unable to find a ranchu in your local fish shop, the next option is an online fish shop, as the number of those has increased dramatically. Doing a quick search on Google should come up with some great results. I’ve previously ordered all my fish online, even the tropical fish.

Is My Ranchu Purebred?

How to spot if your ranchu is purebred: One simple way is to look at the curve from the top of the head to the tail. If it is a nice and smooth curve, you most likely have a purebred; if there are a few lumps or higher bumps, you may have a cross-bred ranchu which has not been totally bred out of other goldfish species features.

Goldfish Competitions

Goldfish competitions are very popular in Japan, and the ranchu is one of the most popular contest fish. Japan holds many competitions that judge your ranchus for health, color and especially the famous head growths.

Some serious fish judging going on!

Some serious fish judging going on!

R.I.P. Ranchu

Sadly, my red and white ranchu passed away a few weeks after I initially wrote this article, and the reason he died was that he kept trying to pick up food off the gravel. He ended up eating a lot of little bits of gravel and not being able to pass them through his system. When I pulled him out of the tank, he weighed a ton, full of pebbles—poor fish.

Anyway, this is just a reminder so you can choose a gravel size that's easier enough for them to pass or too big to swallow—or maybe choose a safer option than gravel, even though no gravel means less room for bacteria to live in, and it takes away from your aquaculture designs.


LissaLmt on April 08, 2019:

Its best to stay away from sand and small pebbles as they may cause indigestion and essentially death to your fish friends.

Mikey Jackson101 on March 30, 2019:

Hi, I just got a giant 56 gallon tank and put some EcoComplete and Fluval Stratum as the "gravel" for my ranchu. He means a lot to me, do you think he's running a high risk of swallowing the pebbles? What are the signs of ingestion? Thank you on February 03, 2015:

Ranchus can be fed a few peas without jacket every few days, just squeeze the pea out of casing crushed a little between your fingers, this helps eliminate swim bladder.

sharon. on July 27, 2014:

Hi, I've had my little ranchu for a year now. What a lovely little fish. He is in a 14 litre tank with two small goldfish which the retailer assured me would be fine. I have a good filter system, aimed at the tank wall and have had the water tested and it is fine.

He appeared fine this morning but by early evening is spending most of his time at the bottom of the tank , underneath the filter,not interested in eating. He does love to pick up the gravel but it is quite small. Could you advise please??

Kallsop on September 23, 2013:

My fish keep coming up for air every like 5 second and staying up there for awhile should I be worried

Kallsop on September 23, 2013:

I have two ranchus, so is sand good as gravel and how much do I put in

desiree on August 20, 2013:

both eyes of my ranchu being dig out by another fish i hate myself so much wat should i do to keep it alive

mary anne on July 29, 2013:

I just lost my lovely ranchu.....I live in Oregon and having a hard time to find another......I live on the central Oregon coast.....nothing in Salem or Eugene the two biggest cities nearby have!

Klerra on April 21, 2013:

Hey I have black ranchu and over the past few days, a white patch of skin has formed over his nose and am not sure what it is

PLEASE HELP ME!!!!!!!!!!!!!!!!!!! :(

Kris Weber from Saint Cloud, Minnesota on March 16, 2013:

I had a lot of fun with my goldfish for it's 6 years of living. I made some cool videos on me taking care of it too.

What people don't know is that fishbowls are way too small for these fish and they wonder why they die so much. "Oh Goldfish only die" is what I always hear.. Well... take him out of a flower Vase and maybe he would live longer! Geesh people make me angry!

Rebecca voaks on September 29, 2012:

Here how do you feed and stroke ranchus? I would think they would die if you touch them don't you?

tia on September 27, 2012:

Also I was very upset when ranchu died I buried him in my garden beside my other fish goldie ):

tia on September 26, 2012:

My black ranchu named ranchu died this morning and I will replace him with the name ranchu 2!!!!!!!!!!!!!!

Shelisa Friend on June 14, 2012:

Hey there! I was wondering if anyone could help me?

My black ranchu has got some sort of red sore on his head =( It almost looks like one of his little lumpy bits has come off!

What is wrong with him? His name is Buddy and he's my favorite fish! I don't want him to be sick =( Please help!

Thank you!

Vicster on June 09, 2012:

I have two black ranchu at my office but one has just got a White patch by his eye....Any ideas?

expectus (author) from Land Downunder on April 19, 2012:

Hey Oscar, a lump near the tail usually indicates that its not a fully bred ranchu and may have some lionhead in him or other species, unless of course it appears to be some sort of growth

Oscar on March 13, 2012:

I need help to distigust my ranchu bc he had a smooth back till he started to grow he starte to grow a bump almost by the tale

Emma on March 09, 2012:

Please help. I think my ranches are sick!! Their under bellies are sort of red and blotchy. Im not sure what's wrong :( please help if you can- what can I do? Tank is clean and I only give them a small amount of food, any help would be greatly appreciated!! Thank you

Jess on March 01, 2012:

I have a ranchu, moor, oranda and fantail. This is my first time having a ranchu and so far I find this one is giving me the most problems. I find when I do water changes the ranchu looks like it has swim bladder issues for a couple days. Also, when I got the ranchu he appeared to have a tiny bit of fin rot and a somewhat deformed tail. I have treated him 3 times for tail rot and it hasn't improved at all. Im not sure what else to do. I've sat and watched my tank for a while and there doesn't appear to be any bully fish. The 3 other fish are fine so I know my water quality is great. I do 30% water changes every week. I don't know what else to do for my little ranchu :(

Bec on January 30, 2012:

Can you put 2 ranchu's together in a tank? or will they fight?

brian on November 01, 2011:

love ranchus black ones are so cute keep 8 outside in a 500 litre koi showing tank and feed them hikari in purple pack bloodworm .peas cooked rice and small earth worms they are doingreally well .The tank is in a south faceing spot by my door and i keep it natual as possible with plants

Mclegs on October 29, 2011:

R.I.P my ranchu, it died under suspiious circumstances. the tank; clean. had been fed that day. wasn't heavy when i lifted it from the tank.

Any andswers?

vicki on October 15, 2011:

I bought a ranchu a week ago, its the cutest thing ive ever seen, i thing it maybe of mixed breed, but that is what makes it all the more special. I love it to bits. I am hoping to get a couple more soon.

Ben on October 10, 2011:

Ive got 2 ranchu's a pealscale with tropical fish the tank is always at 21c and there all happy.

expectus (author) from Land Downunder on October 05, 2011:

ranchu and fantail will be happy together aslong as they have enough space

Mclegs on October 01, 2011:

i just got a Ranchu, (i litterly just put it in the tank and was lookin online of photos to show my friends when i came across this) and was wondering can put a fantail in the same tank?

Goldfishgarage on August 25, 2011:

Ranchu are the king of goldfish! I breed them to try to encourage the growth of the hobby in the USA. Please visit my blog if you are interested in ranchu. goldfishgaragedotcom.

renz on August 08, 2011:

i barely got 2 ranchu goldfish. there both the same color, orange. but i have troble telling weather if ones a boy and ones a girl

Taylor on June 07, 2011:

can I have one ranchu in a 20 gallon tank?

JT on March 25, 2011:

I have 2 black ranchu, one of them is not eating n the other one swims slightly slanted. Pls help.

expectus (author) from Land Downunder on March 05, 2011:

saboo - your ranchu should do fine with those other fancy goldfish :)

glad it helped Jade :)

Jade Evans from Sydney, Australia on March 02, 2011:

Great hub. Have found the tip about duckweed especially helpful as I have continual harvest in my outdoor pond. I love Ranchus, but have had a bit of trouble with them over the years with swim bladder problems. But the two I have now are in fine form. Might be due to the duckweed! Thanks

saboo on January 13, 2011:

Enjoyed reading ur article, i have one oranda and two ryukins and I was wondering if putting a ranching in the mix would b a good idea?

Lee on October 10, 2010:

The typical behaviour is apathy and i also have noticed swelling of the belly , no protruding eyes , scales stay at the body.

the fish are not gasping for air.

ammonia 0, nitrite 0, nitrate 12,5mg/l, ph 7,5-8, KH 6

Temperature 75 Fahrenheit/ 24-25°C.

A friend suggusted maybe the current caused by my external filter (1028L/h waterflow) is too strong, so i pointed the incoming water to the tank wall.

i did have problems with water quality in the beginning with high nitrite and ammonia, but this is not a problem anymore.

expectus (author) from Land Downunder on October 10, 2010:

maybe the lack of gravel is making it hard for good bacteria to grow in your tank. you can try setting up the tank with some water from an existing tank just so you have some of bacteria and waste to start the cycle off.

have you seen any strange behavior from your fish? gasping for air at the top?

Lee on October 10, 2010:

Ranchu are indeed wonderful, but really difficult to find in Germany und even more difficult to keep.

I am lucky I have found a provider, but still.

Although my water test turn out fine, the fish won't survive. started out with seven, now 5 Ranchu (5cm) in a 240 liter tank. I only feed once every 3-4 days, I begin to wonder whether the lionhead sinking pellets by hikari mini pellets is to large for them.

I'd be happy for any advice. ps.: i don't use gravel. Bare bottom tank

expectus (author) from Land Downunder on August 22, 2010:

thanks for the comments, ranchu's are wonderful, just make sure you have gravel which is either too big for them too swallow or small enough that it will pass through. lost my red and white ranchu (pic above) due to gravel choking:(

steve fish on August 20, 2010:

good info ^^, i used to keep marines but i have now got 2 ranchu , they are about 60mm long gold and white , they are only in a 10gal tank at the mo with a filter but as they grow i will get them a bigger tank , all in all a lovely fish that we hope will live a long time , our other goldfish has just popped its clogs but he was 15 years old

finatics on August 19, 2010:

Ranchus are so cute! It's interesting that they hold Ranchu competitions in Japan. Thanks for the great article, I enjoyed reading it. Voted up for usefulness. :)

Michelle Simtoco from Cebu, Philippines on February 06, 2009:

Ranchu seems to have escaped the aquarium for awhile to call our attention. Well, congratulations. This hub has made its way into this week hubnuggets list. Do click this link as Funride will explain what you need to do. And be sure to vote okay? Spread the word to your friends :)

Johnny on February 01, 2009:

hooray i love ranchu's

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