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Carassius auratus var.
The 'King of Goldfish.' Tail-less with a round body and prominent head growth (wen). Active show culture — top specimens fetch hundreds of thousands of yen.
The Ranchu, often called the "King of Goldfish" in Japan, is a hooded fancy goldfish developed in Japan during the late Edo and Meiji periods. Distinguished by the complete absence of a dorsal fin and a rounded, egg-shaped body, the Ranchu is prized for its symmetrical top-view appearance and the prominent fleshy growth (wen) covering its head. In competitive shows, judges evaluate the quality of the wen, body shape, and overall balance when viewed from above. Ranchu have a gentle temperament and do best when kept with similarly slow-moving varieties. They thrive in shallow tanks or traditional Ranchu bowls with minimal water flow, and some keepers use green water (phytoplankton-rich water) to enhance coloration and wen development. Maintaining stable water quality at pH 7.0–7.5 and avoiding sudden temperature changes are essential for their health.
Source: Wikipedia (CC BY-SA 4.0)
The Ranchu lives 10-15 years.
The Ranchu grows to 15-25cm.
Origin
Japan
Lifespan
10-15 years
Size
15-25cm
Temperature
15〜28℃(適温20〜25℃)
Sources: FishBase / Aqueon Goldfish Care Guide
Goldfish varieties are line-bred for body shape, tail type, scale type, and coloration. Traits such as protruding eyes, transparent scales (calico), and albinism are single-locus traits.
Sources: Wikipedia - Goldfish (Varieties) / Goldfish — Wikipedia (Japanese edition, varieties)
A curated selection of notable morphs. Inheritance modes are a breeding-planning guide; actual appearance varies with combos.
Edited & verified by: BreederDirect editorial team
The taxonomic, regulatory, and husbandry data on this page are compiled and verified against the authoritative primary sources below.
Accepted name: Carassius auratus var. (Linnaeus, 1758)
Synonyms: Cyprinus auratus Linnaeus, 1758, Carassius auratus auratus (Linnaeus, 1758), Cyprinus thoracatus Valenciennes, 1842, Carassius burgeri Temminck & Schlegel, 1846, Cyprinus chinensis Gronow, 1854
Authority databases: FishBase · GBIF · FishBase: Carassius auratus · GBIF: Carassius auratus · Nihon Ranchu Association (JA)
Nomenclature follows global taxonomic authority databases.
Find listings for this species
Goldfish pellets, bloodworms, brine shrimp
60cm+ tank or concrete pond. Bare bottom easiest to manage
pH 7.0-7.5 neutral. Weekly 1/3 water changes
Bloodworms, high-protein food, and clean water promote wen development
Prone to swim bladder issues. Overfeeding and cold water are main causes
Advanced. This is an advanced-level species. It requires specialized equipment and advanced husbandry skills with precise environmental control.
The ideal temperature for Ranchu is 15〜28℃(適温20〜25℃). Avoid sudden temperature changes and maintain a stable environment.
The average lifespan of Ranchu is 10-15 years. With proper care and nutrition, they can live a long and healthy life.
Ranchu typically reaches 15-25cm as an adult. Size may vary depending on care conditions and individual genetics.
Ranchu feeds on: Goldfish pellets, bloodworms, brine shrimp. Aim for a balanced diet with appropriate feeding frequency.
The price of Ranchu varies significantly depending on variety, size, and individual quality. Check our market price page for the latest pricing information.
Last updated: August 31, 2026