Ryukin Goldfish

Carassius auratus

Animalia›Chordata›Actinopterygii

Variety of Fancy Goldfish · ryukin

📍 Japan

A fancy goldfish with Japanese origins, recognized by its prominent shoulder hump directly behind the head and a short, deep body with long, flowing double tail fins. Hardier than many fancy varieties, it is active and competitive for food, making it better suited to tanks with other vigorous fancy goldfish rather than delicate slow swimmers.

Size8"

Min Tank20g

peaceful

Zonemid

Care Guide

Diet

Ryukins are omnivorous and should be fed high-quality sinking pellets designed for fancy goldfish once daily, with portions they can consume in 2-3 minutes. Supplement with blanched vegetables (peas, zucchini), frozen foods (brine shrimp, daphnia), and occasional live foods to promote digestive health and vibrant coloration.

Behavior

Active and competitive swimmers with a distinctive hovering posture due to their body shape, Ryukins are social and enjoy exploring their environment. They are enthusiastic feeders that may uproot plants and stir substrate while foraging, and they thrive best with other vigorous fancy goldfish varieties rather than slow or delicate species.

Breeding

Breeding Ryukins in captivity is possible but requires careful conditioning and specific triggers like temperature drops and increased feeding. Spawning typically occurs in spring when water temperature drops from 24°C to 18°C; eggs are adhesive and hatch in 5-7 days. Fry are small and require infusoria or liquid fry food initially, making large-scale breeding challenging for most hobbyists.

Tank Mates

Fancy Goldfish

Ryukins are best housed with other fancy goldfish varieties that share similar water needs and competitive feeding behavior

excellent

Black Moor Goldfish

Compatible fancy goldfish with similar size, temperament, and water parameter requirements

excellent

Oranda Goldfish

Another fancy variety that matches Ryukin vigor and feeding competitiveness

excellent

Gold Mystery Snail

Snails help with algae control; Ryukins may occasionally nip at them but generally coexist peacefully

good

Ramshorn Snail

Smaller snail option that provides cleanup services with minimal conflict

good

Common Diseases

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, rapid breathing, flashing against surfaces, lethargy

Treatment

Raise temperature gradually to 28-29°C, perform daily 25% water changes, use aquarium salt (1 teaspoon per gallon) or commercial ich treatment; maintain for 10-14 days

Fin Rot

Symptoms

Frayed or deteriorating fins, white or black edges on fin tissue, fin loss

Treatment

Improve water quality with frequent partial water changes, remove uneaten food promptly, use antibacterial medication if severe; ensure adequate filtration

Swim Bladder Disorder

Symptoms

Difficulty maintaining buoyancy, floating at surface or sinking, tilted swimming posture

Treatment

Feed blanched peas to aid digestion, perform 25% water changes, reduce feeding temporarily; may be caused by constipation or poor water quality

Dropsy

Symptoms

Swollen belly, raised scales giving pinecone appearance, lethargy, loss of appetite

Treatment

Isolate in hospital tank, perform frequent water changes, use antibacterial treatment; prognosis is poor; often indicates organ failure or bacterial infection