Watonai

Looks how to spot one

Scaled fish with a long body, long flowing fins and a double (twin) tail

Think of a long-bodied, comet-like goldfish wearing twin tails. The watonai has the longer body of a ryukin stretched out, a large wakin-like head, and long, flowing tail and fins with a paired anal fin. It grows to a good size, around 30 cm.12

Personality what they are like

Gentle and adaptable; Japanese sources describe it as robust and able to share a tank with other fish.1

Daily activity how busy a day looks

Moderate. A graceful swimmer that enjoys long, open swimming space.12

Grooming and care the hands-on bits

Needs no special conditions beyond good general goldfish care: efficient filtration, weekly partial water changes of about 30% with dechlorinated water, roughly 10 to 21 C and a pH of about 6 to 8.1536

Home where they are happiest

Because it grows to around 30 cm, give it a large aquarium or pond; plan for at least 60 litres per goldfish and a tank at least 100 cm long for a group.156

Food basics what goes in the bowl

Omnivores. Offer a goldfish-specific pellet as the staple, which suits their need for less protein and more carbohydrate than many fish foods. Add chopped vegetables such as peas or spinach and small amounts of daphnia or brine shrimp as treats. Feed two or three small meals a day, giving only what is eaten within two to five minutes.73

Company who they like around

Sociable and peaceful; FishBase suggests goldfish groups of five or more. It mixes well with other calm goldfish of a similar size.61

The story where it all began

The watonai was produced in Japan by crossing the ryukin with the wakin and was already being kept in the Edo period. Pure lines are rare today and are mostly kept by dedicated breeders and research facilities.12