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Ranchu goldfish
No dorsal fin, with the rear back curving down toward the tail
Ranchu combine headgrowth with a smooth back lacking a dorsal fin. Compared with lionheads, they have a more curved rear back and different tail attachment. Orandas retain a dorsal fin. A side illustration cannot replace a top-view tail assessment.
- Adult length
- About 10 cm
- Lifespan
- Up to 30 years
- pH
- 7–8.4
- Hardness
- 5–19 dGH
- Natural habitat
- Wild habitats include rivers, lakes, ponds and ditches, often in vegetated still or slow water; ornamental goldfish are domesticated forms.
Assess balance, swimming and feeding in the individual fish. Shared species identity does not guarantee compatible care. Avoid sharp decor; plants may still be disturbed or eaten. Swimming and feeding ability vary among forms. Provide filtration, oxygenation and maintenance.
Appearance and identification
Ranchu lack the dorsal fin retained by orandas. The distinction from lionheads involves rear-back and tail attachment, not headgrowth alone.
Same-species behaviour
Assess individual swimming and feeding.
Space requirements
Avoid small, unfiltered containers.
Diet and feeding
Use an appropriate goldfish diet with varied foods, adjusting to condition and water quality.
Compatibility limits
Active single-tailed fish may outcompete slower double-tailed forms. Avoid fin nippers and overly competitive companions.
Aquarium environment
Goldfish may eat or uproot plants.
Goldfish
Sources
www.aqueon.com ↗ 2026-10-22
www.fishbase.se ↗ 2026-10-25
www.bristol-aquarists.org.uk ↗ 2026-10-22
www.goldfish-types.info ↗ 2026-10-22
www.goldfish-types.info ↗ 2026-10-22
www.goldfish-types.info ↗ 2026-10-22
www.goldfish-types.info ↗ 2026-10-22