Red Ryukin Gold

 

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

Category	Detail
Scientific Name	$Carassius\ auratus$
Common Name	Red Ryukin, Ryukin Goldfish, Fantail Ryukin
Origin	Aquarium-bred hybrid (developed in Japan/China)
Adult Size	6–10 inches (15–25 cm)
Temperament	Peaceful, active, gregarious, voracious eater
Lifespan	10–15+ years
Care Level	Easy to Moderate (Hardier than most other fancy goldfish)

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Appearance and Sexual Differences

 

• Short Description: A heavy, deep-bodied goldfish with a distinct, often triangular body shape created by the prominent arch or hump on its back behind the head. It possesses a double caudal (tail) fin that can be quite flowing.
• Coloration: Typically solid red, red-and-white, or red-and-orange. Males develop small white tubercles (breeding stars) on the gill plates and pectoral fins during spawning season. Females are visibly larger and more rounded/plump when carrying eggs.
• Fins: Long, double tail, pectoral, and anal fins.
• Behavior: An active, moderately fast swimmer compared to other fancy goldfish. They are highly social and thrive in groups. Like all goldfish, they produce a high amount of waste and are prone to digestive issues due to their compacted body shape.

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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. A 55-gallon tank is often a good starting point for a small school.
• Schooling: Highly social; best kept in groups of 2 or more of similar slow-to-moderate swimming fancy varieties (e.g., Oranda, Fantail, Black Moor). Avoid fast single-tailed goldfish.
• Temperature: Cold/Cool Water Range: $65^\circ$–$75^\circ\text{F}\ (18^\circ$–$24^\circ\mathrm{C})$. Avoid tropical temperatures and sudden fluctuations.
• pH Level: Highly adaptable: 6.0 to 8.0. Requires robust filtration (rated 3–5 times the tank volume) and frequent, large water changes (25–30% weekly) to control high waste levels.
• Aquascape: Requires ample open swimming space. Use smooth, fine substrate (sand or rounded gravel) to prevent injury to their sensitive mouth as they forage. Avoid sharp décor. Live plants may be uprooted or eaten, so use sturdy species (Anubias) or artificial plants.

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Diet and Feeding

 

The Red Ryukin Goldfish is an omnivore, susceptible to bloat and swim bladder disorder.

• Staple Diet: High-quality sinking goldfish pellets or granules (sinking food is vital to prevent gulping air, which causes digestive issues).
• Supplementation: A diet rich in fiber is necessary. Offer blanched fresh vegetables (shelled peas, zucchini, spinach) regularly to aid digestion and prevent constipation. Protein treats should be minimal.
• Schedule: Feed small portions once or twice daily. Never overfeed. Soaking dry food before feeding is highly recommended to prevent it from expanding in their stomach.

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Compatibility

 

• Caution: Slow swimmers and poor competitors compared to slim-bodied fish. Do not keep with highly active or aggressive fish (Tropical Barbs, large Danios).
• Good Tank Mates: Only other slow-to-moderate swimming Fancy Goldfish (e.g., Orandas, Lionheads, Fantails). Larger, peaceful bottom-dwellers like Mystery Snails or peaceful weather loaches can also be suitable.