Ranchu Goldfish Care Guide
The ranchu goldfish (Carassius auratus) is a highly prized fancy goldfish in the UK, often referred to as the "king of goldfish." Known for its rounded body, lack of dorsal fin, and prominent head growth (wen), it's a favourite among enthusiasts.
In this guide, you'll learn everything you need to know about ranchu goldfish care, including tank size, water conditions, compatibility, feeding, and typical UK prices - plus how to buy or sell them locally.
Quick facts about Ranchu Goldfish
Ranchu goldfish are a dorsal-less fancy variety bred for their smooth back curve and head growth. They are traditionally viewed from above, especially in shallow ponds or tanks.
They are slow swimmers and require carefully selected tankmates and environments.
Carassius auratus
15-20 cm
Domesticated (developed in Japan from Chinese lionhead varieties)
100L+ (single fish)
10-15+ years
Peaceful, slow-moving
18-24°C
Omnivore (sinking pellets, vegetables, frozen foods)
6.5-8.0
£15-£50+ per fish
How Many Ranchu Goldfish Should You Keep?
Ranchu goldfish are social and should be kept with other suitable fancy goldfish.
- Keep at least 2 where possible
- Only house with similar slow-swimming varieties
- Ensure sufficient space per fish
Overstocking can lead to:
- Poor water quality
- Increased competition for food
- Stress and stunted growth
Proper stocking is especially important due to their body shape and waste production.
Ideal Tank Conditions for Ranchu Goldfish
Creating the right environment is key to maintaining ranchu health and appearance.
- Tank Setup: Spacious aquarium with open swimming areas
- Substrate: Fine sand is ideal to prevent injury
- Plants & Decor: Minimal, smooth decor to avoid damage
- Water Conditions: Stable, well-oxygenated water
- Filtration: Strong filtration is essential
- Lighting: Moderate lighting is suitable
Shallow tanks are sometimes preferred to support their swimming ability.
Compatibility with Other Fish
Ranchu goldfish require careful tankmate selection.
- Good Tankmates: other slow fancy goldfish such as lionhead, oranda, and ranchu varieties
- Avoid: fast swimmers (common/comet goldfish), tropical fish, and fin-nippers
Their lack of dorsal fin and slow movement make them vulnerable to competition.
Are Ranchu Goldfish Easy to Care For?
Ranchu goldfish are moderately difficult to care for and are best suited to hobbyists with some experience.
They require:
- A carefully maintained tank
- Gentle tankmates
- Monitoring of wen health
- Regular maintenance
Their unique body shape can make them more sensitive than standard goldfish.
Ranchu Goldfish Price in the UK
In the UK, ranchu goldfish typically cost between £15-£50+ per fish. High-quality or show-grade specimens can cost significantly more.
Prices vary depending on:
- Body shape and symmetry
- Wen development
- Colour and lineage
- Shop vs specialist breeders
They are considered a premium fancy goldfish variety.
Where to Buy Ranchu Goldfish in the UK
Ranchu goldfish are available from specialist aquarium shops and dedicated breeders.
Sourcing fish locally can:
- Reduce transport stress
- Allow you to assess body shape and quality
- Offer better value
TankMate UK helps connect fishkeepers who want to buy, sell, or rehome fish safely - without shipping.
Can You Sell Ranchu Goldfish?
Yes - ranchu goldfish are often sold or rehomed by hobbyists and breeders.
Selling locally is often the best option, as it:
- Minimises stress for the fish
- Avoids the risks of transport
- Helps connect with knowledgeable buyers
TankMate UK allows you to list fish quickly and find local buyers.
Feeding Ranchu Goldfish
Ranchu goldfish require a balanced and appropriate diet.
Key Tips:
- Feed high-quality sinking pellets
- Supplement with vegetables like peas and spinach
- Offer occasional frozen or live foods
- Avoid overfeeding
Sinking foods help reduce buoyancy issues common in fancy goldfish.
Common Problems with Ranchu Goldfish
Swim bladder issues, often caused by:
- Poor diet
- Overfeeding
Wen overgrowth or infection, linked to:
- Poor water quality
- Injury
Difficulty swimming, due to:
- Body shape
- Strong currents
Why Ranchu Goldfish Are So Popular
- Unique dorsal-less body shape
- Prominent head growth (wen)
- Considered the "king" of goldfish
- Highly prized by enthusiasts
- Wide variety of colours and forms
When kept correctly, ranchu goldfish are a rewarding and visually impressive addition to a specialist aquarium.
Frequently Asked Questions
They have been selectively bred to have a smooth, curved back.
They are better suited to hobbyists with some experience.
No, they are coldwater fish but require stable temperatures.
At least 100 litres for one fish, with more space for additional fish.
Looking to Buy or Sell Ranchu Goldfish Locally?
TankMate UK connects fishkeepers who want to buy, sell, or rehome fish safely within their local area.
Whether you're stocking your aquarium or passing fish on to a new home, you can:
- Browse fish available near you
- List your own fish in minutes
- Avoid the risks of transport