Tosakin Goldfish - Tips and Characteristics

Quick Statistics - Tosakin
Country of Origin: Japan
Family: Cyprinidae
Scientific Name: Carassius auratus
Environment: Freshwater fish
Temperature: 65° - 78°F
Type: Twin Tail
Diet: Omnivore
Food: Pellets, flakes, live food, veggies and fruit
Adult Size: 4-8" (inches)
Lifespan: 10-15 years or more
Care Level: Medium
Temperament: Friendly and social

The Tosakin goldfish is truly the caviar of all goldfish varieties. It's believed to have been developed from the Ryukins and its rarely seen in countries other than Japan. Tosakin are the only twin-tailed goldfish that have an undivided tail.

They have a short egg like body, and all the fins except the tail are similar to the Fantail. The caudal fins of the Tosakin are completely fixed, forming a large tail fin that spreads horizontally. Considered a 'top-view' fish, it's traditionally kept in shallow, aquariums or ponds so that viewers can enjoy the gentle swimming of the fish.

As all goldfish, the Tosakin eats almost every kind of fresh, flake or frozen food, but because of its deep body make it especially prone to Swim Bladder problems.

If kept in well maintained aquariums, this goldfish can reach a size of 4-8 inches. The average lifespan is somewhere between 10-15 years. Available in the traditional orange or orange-and-white, they are also red, red-and-white, yellow, calico and black.

You also need to know...

All fancy goldfish are poor swimmers and have no chance in winning any races when competing for food with other faster single-tails. It's tail fin should only twist once or twice on each side.

U.S. attacks in World War II and an earthquake in 1948 in Japan were believed to have wiped out the Tosakin variety. However, Mr. Hiroe Tamura managed to find six fish and from there he was able to revive the Tosakin.


Best tank mates for the Tosakin are the Fantail, Ryukin, Black Moor, Oranda, Lionhead and in general most of the slow swimming goldfish. Please do not mix Tosakin with faster varieties like Common, Comet or Shubunkin goldfish.

Love to you,

Image credits to: Petalo Negro(Argentina) @