Black Ranchu Goldfish 12cm

The Black Ranchu Goldfish is a highly appreciated variety of fancy goldfish, often called the "King of Goldfish" due to its unique appearance and royal status among aquarists. Developed originally in Japan from the Chinese Lionhead, this specific color morph is celebrated for its deep, velvet-black coloration.

Distinctive Features

No Dorsal Fin: The completely smooth, downward-curving, arched back is their most famous trait.

The "Wen": As they mature, they develop a fleshy, brain-like head growth known as a hood or wen.

Egg-Shaped Body: They have a very round, compact, stout body with a short, tucked-in tail fin.

Color Shifting: Their dark pigment is caused by high melanin. Genetics, water quality, sunlight, or aging can sometimes cause their color to shift to bronze, orange, or white over time.

Quick Care Overview

Tank Size: Minimum 100 liters (approx. 30 gallons) for a single fish. They are slow, clumsy swimmers that require plenty of horizontal swimming space.

Water Temperature: Prefers a stable temperature between 18°C and 24°C (64°F - 75°F).

Dietary Needs: Omnivorous feeders. They should eat high-quality sinking pellets and occasional fresh treats like brine shrimp. Sinking food is best because their body shape makes them susceptible to swim bladder issues if they gulp surface air.

Tank Mates: Keep them strictly with other slow-moving, dorsal-less fancy goldfish (like other Ranchus or Lionheads). Faster fish will easily outcompete them for food.