Source: Wikimedia Commons
Ranchu
AdvancedCarassius 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.
Difficulty
Advanced
Temperature
15〜28℃（適温20〜25℃）
Lifespan
10-15 years
Size
15-25cm
Diet
Goldfish pellets, bloodworms, brine shrimp
About
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)
Basic Info
Origin
Japan
Lifespan
10-15 years
Size
15-25cm
Temperature
15〜28℃（適温20〜25℃）
Diet
Goldfish pellets, bloodworms, brine shrimp
Care Guide
Container
60cm+ tank or concrete pond. Bare bottom easiest to manage
Water
pH 7.0-7.5 neutral. Weekly 1/3 water changes
Wen Growth
Bloodworms, high-protein food, and clean water promote wen development
Notes
Prone to swim bladder issues. Overfeeding and cold water are main causes
AdvancedPremiumShow cultureWen growth
Ranchu FAQ
QHow difficult is it to keep Ranchu?
A
Advanced. This is an advanced-level species. It requires specialized equipment and advanced husbandry skills with precise environmental control.
QWhat is the ideal temperature for Ranchu?
A
The ideal temperature for Ranchu is 15〜28℃（適温20〜25℃）. Avoid sudden temperature changes and maintain a stable environment.
QWhat is the lifespan of Ranchu?
A
The average lifespan of Ranchu is 10-15 years. With proper care and nutrition, they can live a long and healthy life.
Ranchu Q&A
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