Ryukin Goldfish Care Guide - Setup, Feeding & Breeding

Ryukin Goldfish are instantly recognisable by their tall, rounded bodies, prominent shoulder hump and flowing double tail. They are available in many colour forms, including red, white, orange, calico and combinations of these shades, with metallic or partly translucent scales. Their compact, high-backed shape gives them a distinctive appearance among fancy goldfish varieties.

These are generally peaceful, curious fish with a lively but unhurried manner. Ryukins often investigate their surroundings and learn to associate their keeper with feeding time. They are social without being true shoaling fish, and they usually spend much of their time exploring open areas or searching through the substrate.

In the wild, the ancestral goldfish is associated with slow-moving freshwater habitats such as ponds, marshes, floodplain waters and gently flowing streams. Its body shape and feeding behaviour reflect an adaptable omnivorous carp lineage that spends considerable time foraging among plants, sediment and submerged surfaces.

The Ryukin was developed for its exaggerated body profile and elegant tail rather than as a naturally occurring population. Like other fancy goldfish, it can be vulnerable to buoyancy and swimming problems when selectively bred to an extreme, so fish with a balanced body and freely moving fins are preferable.

Ryukin Goldfish are a domesticated fancy variety of Carassius auratus. Goldfish originate from East Asia, particularly China, while the Ryukin form was developed and refined in Japan from earlier fantail-type goldfish.

A single adult Ryukin Goldfish should have at least 150 litres, with around 180–200 litres recommended for a pair and additional volume for each further fish. A practical footprint is about 120 × 45 cm for one or two adults; a long, broad tank is more useful than a tall aquarium because Ryukins are deep-bodied swimmers and produce substantial waste. Use strong filtration with gentle, well-distributed flow, leaving generous open swimming space. A smooth sand or rounded-gravel substrate, robust plants, and décor without sharp edges are suitable, while delicate plants may be uprooted or eaten.

Ryukin Goldfish can reach approximately 20–25 cm (8–10 in) in total length, including the tail, although many aquarium specimens remain closer to 15–20 cm. Females are often slightly larger and deeper-bodied than males.

Ryukin Goldfish are omnivores and should receive a varied diet based on a good-quality sinking fancy-goldfish pellet or gel food. Supplement this with blanched vegetables such as peas, spinach, courgette and lettuce, along with occasional frozen or live foods including daphnia, brine shrimp and bloodworms. Small, regular meals are preferable to a single large feeding, and sinking foods can help reduce surface gulping in fish prone to buoyancy issues.

Ryukin Goldfish are best housed with other fancy goldfish of comparable size and swimming ability, such as Fantails, Orandas, Ranchus and Lionheads. Avoid fast, competitive varieties such as Common, Comet and Shubunkin goldfish, which may outcompete them for food. Tropical fish that require significantly warmer water, fin-nipping species and very small fish are unsuitable companions. White Cloud Mountain Minnows are sometimes kept with goldfish in cool aquaria, but differences in adult size, temperature preference and feeding behaviour mean a fancy-goldfish community is usually the safest choice.

Ryukin Goldfish are egg scatterers that can breed readily when mature males and females are conditioned with a varied, nutritious diet. Spawning is often encouraged by a gradual rise in temperature during spring-like conditions. The female releases adhesive eggs among fine-leaved plants, spawning mops or other suitable surfaces while one or more males fertilise them. Remove the adults after spawning, as they may eat the eggs. Hatching generally occurs within several days, and the fry require very small foods until they are large enough to accept crushed flakes or appropriately sized live foods.

Mature females are usually broader through the abdomen, particularly when carrying eggs, while males tend to be slimmer. In breeding condition, males may develop fine white tubercles on the gill covers and leading edges of the pectoral fins, and they often chase females.