Lionhead Ranchu Goldfish (Carassius auratus)

Discover the Lionhead Ranchu goldfish

The Lionhead Ranchu goldfish is a round, dorsal-less fancy goldfish (Carassius auratus) whose head slowly gathers a soft, bubbly hood as it grows. The fish in our photographs is metallic red-orange with a paler belly and a short, divided tail held up behind a smooth, finless back. It belongs to the carp family, Cyprinidae, and FishBase gives the species’ native range as East Asia; the fancy forms are entirely the work of breeders.

In Japan the ranchu is called the king of goldfish, according to Practical Fishkeeping’s feature on the breed, and fine Japanese fish can sell for prices similar to some koi. The Bristol Aquarists’ Society ranchu standard records that the variety was developed in China and further developed in Japan, that ranchu are also called buffalo-heads in the Far East, and that calico ranchu are known in Japan as edonishiki. The lionhead is the Chinese, flatter-backed relative. Because most shop ranchu come from China, the trade name “lionhead ranchu” is widely used for fish that combine features of both.

Science backs up how distinct these fish are. A 2020 genome study of 27 goldfish strains located genetic regions associated with dorsal fin loss, and Ota and Abe’s review notes that ranchu carry only 19–23 vertebrae against 25–29 in the ryukin, which fits their short, compact build.

Read the shape: back, tail and hood

These points come from the Bristol standards for both varieties and from Paul Green’s comparison in Practical Fishkeeping. A young fish shows them only faintly; the back line and tail set become clearer over the first year or two.

Check the size, colour and quantity you receive

Each order line is one live Lionhead Ranchu at 3–4 cm body length. The Bristol show standard sets 5.5 cm as the minimum body length for exhibition, so this is a juvenile with most of its growth and hood development ahead of it. Sex is not chosen or guaranteed.

The photographs are representative images of the variety, prepared from a reference picture; they do not show your individual fish. Expect the dorsal-less shape and the colour form pictured, with natural variation in hood, tail and shade. See the rest of our goldfish and coldwater fish or the fancy goldfish category to plan a group.

Watch the hood develop

The Bristol standards ask for a hood well developed in three areas: over the top of the skull, below the eyes and across the gill covers. They note that strong hood growth is common in mature adults, while Practical Fishkeeping describes the lionhead’s growth as large and rounded and the ranchu’s as turning rectangular with age. No source gives a fixed timetable, so treat hood growth as something that builds steadily with good food and clean water rather than a promise of a particular size.

Colour can move too. Practical Fishkeeping notes that a ranchu’s colour can change almost completely as it matures, that many goldfish whiten with age, and that the breeders it interviewed see natural daylight as key to rich colour. A red fish may become red and white over the years; this is normal development, not illness.

Give it a long, wide aquarium

OATA gives fancy goldfish an adult size of about 20 cm and asks for at least 100 litres for the first adult, then 50 litres for each additional adult. The RSPCA sets a floor of 60 litres per goldfish. The Maidenhead Aquatics database suggests a tank around 1.2 metres long and says length and width matter more than height.

Plan by adult fish, not by today’s size

Ranchu of 30 cm are not uncommon on the showbench according to Practical Fishkeeping, so treat these as minimums. Work out your tank’s true capacity with the tank volume calculator and check the whole group with the stocking calculator. A goldfish bowl is never suitable; the RSPCA lists bowls as too small, too unstable in temperature and without room for a proper filter.

Hold the water cool, clean and stable

OATA recommends indoor aquaria only for fancy goldfish and says a heater is rarely needed. The RSPCA puts goldfish at 10–21°C, OATA at 4–25°C with 15–23°C as the best range, and the Maidenhead database at 10–28°C. We suggest holding the tank steady between 15 and 21°C, where the sources overlap. Keep the aquarium out of direct sun, away from radiators and draughts, and give 8–10 hours of light a day as the RSPCA suggests.

Prepare tap water every time

Use a conditioner that neutralises chlorine and chloramine in every bucket of new water, and match its temperature to the tank. Our water treatments cover this. Test your tap once for pH and hardness, enter the results into the water matcher, and read our water chemistry guide if anything falls outside the table. Most fancy goldfish do better in steady water than in water that is constantly being adjusted.

Run a strong filter with a soft outlet

Fancy goldfish produce plenty of waste, so the Maidenhead database asks for efficient filtration, weekly partial water changes and well-oxygenated water in warm weather. OATA adds that fancy breeds prefer gentle flow; a spray bar or a diffused outlet spreads the current, which matters even more for a compact, dorsal-less fish. Practical Fishkeeping does note that Japanese ranchu, being longer in the body than lionheads, suffer fewer swim bladder disorders.

Cycle the filter first. The RSPCA recommends at least two weeks of fishless cycling, testing every other day until ammonia and nitrite have peaked and returned to zero. Our guide to the nitrogen cycle explains what is happening during those weeks.

Keep a simple maintenance rhythm

Decorate around the hood

OATA warns against sharp or rough décor that could damage long fins or delicate eyes, and the soft hood of a lionhead ranchu deserves the same care. Use smooth sand or rounded gravel, smooth wood and rounded stones, and avoid ornaments with tight gaps or rough inner surfaces. Leave a clear, open floor at the front where the fish can find sinking food.

• Choose sturdy plants: OATA notes goldfish may eat soft plants, so tough-leaved plants or good artificial plants last longer.
• Keep the substrate shallow and easy to siphon; goldfish sift through it for food.
• Place décor to the sides and back so the swimming lane stays open.
• Leave the water surface clear for gas exchange.

Feed for buoyancy and steady growth

OATA recommends a goldfish-specific flake, granule or pellet, because goldfish need more carbohydrate than many fish, with daphnia, bloodworm, brine shrimp, blanched lettuce or shelled peas as supplements. Feed once a day and only what is eaten in a few minutes. The Maidenhead database prefers sinking foods and a high-fibre diet, since goldfish swallow air while feeding at the surface and that is linked to buoyancy problems.

Practical Fishkeeping’s ranchu breeders feed twice a day and up to six times a day for young or show fish, but in vats with complete weekly water changes. At home, split the same small daily ration into two meals if you want more frequent feeding.

Use a varied sample week

If the fish starts floating or tipping after meals, OATA suggests changing to a different or slower-sinking food. Our article on why fish swim sideways helps you rule out water problems at the same time.

Bring it home safely

Make sure the tank is cycled and that ammonia and nitrite read zero before delivery day. OATA’s method is simple: lights off, float the sealed bag for about 10 minutes, add small amounts of tank water over up to 20 minutes, then release the fish. Our step-by-step acclimatisation guide covers the details, and our delivery and Live Arrival Guarantee terms explain what to do if there is a problem on arrival.

Check these before release

• Tank temperature within 15–21°C and close to the bag temperature.
• Outlet set gently so a tired fish is not pushed around.
• Lights off and the room quiet for the rest of the day.
• A small sinking meal planned for the next day, not straight away.

Pick slow fancy companions

OATA says fancy goldfish can live alone or with other fancy goldfish, and advises against mixing them with common goldfish, which swim faster, out-compete fancies for food and sometimes nip fins. The Maidenhead database describes the ranchu as sociable and suggests keeping it with its own kind or other fancy goldfish.

Sort companions into three groups

Calm orandas like the Blue Oranda and the Red Broadtail match its pace. If you add a ryukin, feed at two points so the slower lionhead ranchu gets its share. Our comet goldfish guide shows why single-tailed fish are better kept separately, and the tank mates tool checks other ideas.

Spot problems early

A healthy fish, in OATA’s description, has clear bright eyes, whole fins, intact scales, no ulcers or bumps, normal swimming and steady breathing. Look over your lionhead ranchu each day while it feeds.

The Bristol lionhead breeders report that their lionheads live seven to eight years on average and name gill flukes as a regular problem, controlled with lower stocking and frequent water changes. The Maidenhead database suggests that well-kept fancy goldfish can live 15–20 years or more, so the figures vary widely with care.

Understand how ranchu are bred and judged

Japanese ranchu are judged from above in shallow bowls, much like koi, with three to five judges scoring each fish, Practical Fishkeeping reports. Fish in their first year are called tosai, become nisai on the first of January after hatching and oya the January after that. The Bristol ranchu standard was first published in 2011 and updated in 2016.

Try spawning at home

OATA suggests a large tank, about two males to every female, a slow rise to around 20°C and a partial water change to trigger spawning. Eggs hatch in about three days and the adults eat eggs and fry, so separate them. Males show white tubercles on the gill covers and pectoral fins; females are deeper bodied. Expect very few show-quality youngsters: the Bristol lionhead breeders keep about 50 of every 1,000 fry and see about five reach the standard.

Answer Lionhead Ranchu goldfish questions

What is a Lionhead Ranchu goldfish?

A fancy goldfish, Carassius auratus, with no dorsal fin, a short rounded body and a hood of soft growth on the head. The name joins two show varieties: the flat-backed Chinese lionhead and the ranchu, which was developed in China and refined in Japan with a more curved back and a tail set at a steeper angle.

Is a lionhead the same as a ranchu?

No. Practical Fishkeeping and the Bristol Aquarists’ Society both separate them by the back and tail: the lionhead has a flat back and a tail that runs fairly flat, while the ranchu’s back curves down and its tail leaves the body at about 45°. Most shop fish come from China and often sit between the two.

When will the hood grow?

Gradually. At 3–4 cm the hood is only a low cap. The Bristol society notes that good hood growth is common in mature adults, covering the top of the head, the area below the eyes and the gill covers. No source gives a fixed timetable, and hood size varies from fish to fish.

How big does a lionhead ranchu grow?

Plan for about 20 cm, as OATA and the Maidenhead Aquatics database give for fancy goldfish. Practical Fishkeeping notes that show ranchu of 30 cm are not uncommon.

What tank does it need?

At least 100 litres for one adult and 50 litres for each extra adult, following OATA; the RSPCA asks for at least 60 litres per goldfish. Choose a long, wide tank with a mature filter and a gentle outlet.

Will the colour change?

It may. Practical Fishkeeping notes that a ranchu’s colour can change almost completely as it matures and that many goldfish turn whiter with age. The fish you receive is the colour form shown, but we cannot fix its adult colour.

Can it live with other goldfish?

Yes, with other slow fancy goldfish such as ranchu, lionheads, orandas and pearlscales. OATA advises against common goldfish with fancy varieties because they are faster, take the food and sometimes nip fins.

How many fish do I get?

One live Lionhead Ranchu at 3–4 cm per purchase. Sex is not chosen or guaranteed.

Read the care references

• OATA: How to look after fancy goldfish — UK trade guidance on fancy goldfish water values, tank size, flow, décor, feeding, acclimatisation, warning signs, companions and breeding.
• RSPCA: Aquarium environment for fish — welfare guidance on goldfish space, temperature, the nitrogen cycle, fishless cycling, lighting, water changes and why bowls are unsuitable.
• FishBase: Carassius auratus — accepted identity, family, native range, environmental ranges, maximum recorded length and age of the species.
• Bristol Aquarists’ Society: Ranchu — the ranchu show standard: origin, body depth, missing dorsal fin, hood, tail, colours, minimum size and how it differs from the lionhead.
• Bristol Aquarists’ Society: Lionhead — the lionhead standard and breeders’ notes: flat back, hood, colours, lifespan, gill flukes and how few fry reach show quality.
• Practical Fishkeeping: What’s the difference between a Ranchu and a Lionhead? — Paul Green on the back, tail angle and head growth that separate the Chinese lionhead from the Japanese ranchu.
• Practical Fishkeeping: Ranchu, king of goldfish — how ranchu are bred, kept, fed, judged and how their colour changes with age.
• Maidenhead Aquatics fish database (fishkeeper.co.uk): Ranchu — aquarium values, tank length, diet, buoyancy and lifespan notes for the ranchu.
• Ota & Abe (2016): Goldfish morphology as a model for evolutionary developmental biology — peer-reviewed review of goldfish breeding history and the anatomy of dorsal-less, bubble-eyed and pearl-scaled strains.
• Kon et al. (2020): The genetic basis of morphological diversity in domesticated goldfish — peer-reviewed genome study of 27 goldfish strains locating the genetic regions linked to dorsal fin loss and other traits.
• Tropical Fish Co delivery policy — current dispatch days and Live Arrival Guarantee terms.