Red Cap Oranda

fish description – Red Cap Oranda Goldfish Care Guide ($Carassius\ auratus$ ‘Red Cap’ Strain)

Category	Detail
Scientific Name	$Carassius\ auratus$
Common Name	Red Cap Oranda, Redcap Goldfish, Oranda
Origin	Aquarium-bred hybrid (descended from wild carp in Southern China)
Adult Size	8–10 inches (20–25 cm)
Temperament	Peaceful, slow-moving, voracious eater
Lifespan	10–15+ years
Care Level	Moderate (Sensitive to water quality and prone to wen/digestive issues)

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Appearance and Sexual Differences

 

• Short Description: A heavy, ovoid (egg-shaped) bodied goldfish with long, flowing fins and a large, raspberry-like growth (wen) on its head.¹¹ The ‘Red Cap’ variation features the wen strictly as a bright red cap on a pristine white body.¹² They are poor swimmers due to their shape.¹³

   

• Coloration: Body is white or silver; the wen is a vivid red.¹⁴ Sexing is difficult outside of spawning; males develop small white tubercles (breeding stars) on the gill plates and pectoral fins, while females are larger and visibly plumper/fatter when carrying eggs.¹⁵

   

• Fins: Long, delicate fins, often a target for fin-nippers.¹⁶ The large wen can sometimes obstruct their eyesight.¹⁷

   

• Behavior: A peaceful and docile social fish.¹⁸ They are high waste producers and require very clean water.¹⁹ They will root/dig through the substrate.²⁰

   

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Tank Requirements and Water Parameters

 

• Minimum Tank Size: 20 gallons (75 liters) minimum for the first fish, plus 10 gallons for each additional fish.²¹ A 55-gallon tank is ideal for a small, healthy school.

   

• Schooling: Highly social; best kept in groups of 2 or more of similar slow-moving fancy varieties.²²

   

• Temperature: Cold/Cool Water Range: ²³$65^\circ$–²⁴$75^\circ\text{F}\ (18^\circ$–²⁵$24^\circ\mathrm{C})$.²⁶ Avoid high tropical temperatures.²⁷

   

• pH Level: Highly adaptable: 6.5 to 8.0.²⁸ Requires robust filtration (rated 3–5 times the tank volume) and frequent, large water changes (25–30% weekly) to control high waste and keep nitrates low.²⁹

   

• Aquascape: Requires smooth, fine substrate (sand or fine gravel) to prevent injury to the wen or eyes.³⁰ All decor must be smooth and dull-edged. Provide open swimming space. Hardy plants may be used, but must be monitored.

   

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Diet and Feeding

 

The Red Cap Oranda is an omnivore, susceptible to digestive and swim bladder issues.³¹

 

• Staple Diet: High-quality sinking goldfish pellets or granules (sinking food is vital to prevent gulping air).³² Focus on diets with color enhancers.

   

• Supplementation: A diet rich in fiber and low in processed fillers. Offer blanched fresh vegetables (shelled peas, zucchini, spinach) regularly to aid digestion.³³ Protein treats should be minimal.

   

• Schedule: Feed small portions twice daily. Never overfeed.³⁴ Fast the fish one day a week to aid digestion. The wen is prone to infection, so excellent diet and water quality are essential for its health.³⁵

   

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Compatibility

 

• Caution: Slow swimmers and poor competitors for food due to their body shape and obstructed vision.³⁶ Do not keep with fast-swimming fish (Danios, Barbs) or known fin-nippers.³⁷

   

• Good Tank Mates: Only other slow-moving Fancy Goldfish (e.g., Lionheads, Fantails, Black Moors).³⁸ Larger, peaceful bottom-dwellers like large Mystery Snails or peaceful weather loaches can also be suitable.