Ranchu

Ranchu goldfish are premium fancy goldfish known as the "king of goldfish" for their egg-shaped bodies, lack of a dorsal fin, and raspberry-like head growth called a wen. 

Key Overview & Characteristics

• Origin: Developed in Japan (during the Edo period) from Chinese stock (often compared to Chinese Lionheads).
• Appearance: Deep, egg-shaped body, smooth curved back without a dorsal fin, twin tail fins, and a fleshy head hood (wen).
• Size: Typically grows to 15 to 20 cm (6 to 8 inches).
• Lifespan: 10 to 15 years (up to 20 years with pristine care).
• Temperament: Slow, waddling swimmer that requires calm water and gentle tank mates. 

Care Requirements

• Tank Size: Minimum of 150 to 200 liters (approx. 40 to 50 gallons) for a single fish, plus 75 to 100 liters for each additional companion. Never keep them in bowls.
• Water Parameters: Maintain a temperature of 18°C to 24°C (65°F to 75°F) and a neutral-to-slightly-alkaline pH of 6.5 to 8.0.
• Filtration: Heavy-duty filtration is crucial because of their heavy waste output, but water flow must remain gentle to accommodate their weak swimming ability.
• Diet: Feed sinking gel foods or pellets to prevent floating dry foods from causing dangerous buoyancy and swim bladder issues.