The Ranchu Goldfish (Carassius auratus) is a beloved variety of fancy goldfish, notable for its rounded body shape and distinctive lack of a dorsal fin. Known for their playful nature and unique appearance, Ranchu Goldfish are a popular choice among aquarists and are often seen in both home aquariums and competitive shows.
Physical Characteristics:
Size: Ranchu Goldfish typically grow to about 15-20 cm (6-8 inches) in length, although some can reach larger sizes under optimal conditions.
Coloration: They are available in a variety of colours, including orange, red, white, calico, and even black. The vibrant colours are often deep and rich, contributing to their attractiveness.
Fins: Unlike many other goldfish varieties, Ranchus do not have a dorsal fin, giving them a unique silhouette. Their other fins are short and rounded, which complements their overall shape.
Shape: Ranchus have a distinctive round body with a broad, stocky appearance, which contributes to their buoyancy and swimming style.
Temperament: Ranchu Goldfish are generally peaceful and can coexist well with other goldfish and compatible species. They are known for their friendly disposition.
Activity Level: They are moderately active swimmers, often seen exploring their environment and interacting with tank mates.
Community Behaviour: These goldfish do well in community tanks, but it is essential to select tank mates that are equally peaceful to avoid stress and aggression.
Aquarium Care:
Tank Size: A minimum tank size of 80 liters (20 gallons) is recommended for a small group of Ranchu Goldfish, with larger tanks preferred for better water quality.
Water Parameters:
Temperature: Ranchu Goldfish thrive in cooler water, ideally between 18°C to 24°C (65°F to 75°F).
pH: They prefer slightly alkaline water, with a pH range of 7.0 to 7.5.
Hardness: Soft to moderately hard water, with a general hardness (GH) of 4-10 dGH, is ideal.
Tank Setup:
Substrate and Decorations: A soft substrate is recommended to prevent injury. Ranchu Goldfish enjoy a well-planted tank with smooth decorations that provide hiding spots and reduce stress.
Lighting: Moderate lighting is ideal for showcasing their colours. Floating plants can help diffuse the light and create shaded areas.
Filtration: A good filtration system is crucial for maintaining water quality. Regular water changes (about 20% weekly) are essential to keep the tank clean.
Diet:
Ranchu Goldfish are omnivorous and require a balanced diet to thrive. Their diet should include:
Pellets: High-quality sinking pellets designed for goldfish should form the staple of their diet.
Vegetable Matter: Offering blanched vegetables such as peas, spinach, or zucchini provides essential nutrients.
Live or Frozen Foods: Including live or frozen foods like brine shrimp or bloodworms can enhance their diet and promote health.
Breeding:
Breeding Ranchu Goldfish can be rewarding with the right setup:
Breeding Setup: A separate breeding tank with ample space and plants for spawning is recommended. Water should be warm (around 22°C to 26°C or 72°F to 78°F) and well-oxygenated.
Spawning Behaviour: Males will chase females and encourage spawning. After eggs are laid, remove adults to prevent them from eating the eggs.
Fry Care: Once the fry hatch, they can be fed infusoria or finely crushed flakes until they grow larger.
Special Considerations:
Wen Care: The absence of a dorsal fin means that Ranchu Goldfish require special care for their wen, which should be monitored for any signs of rot or disease.
Water Quality: Regular monitoring of water quality is essential to prevent common goldfish ailments.