Tosakin (Tosa)


This very difficult to groom top view fish was developed in Japan before 1868. The exact method of development is unclear, a cross between a Ryukin and a Osaka Ranchu or it is a direct mutation of a Ryukin.

© Merlin Cunliffe 2016

Breed Development

Raising this fish for show is most difficult. Tosakin require shallow, clean water, usually are grown in individual containers or compartments and selection of what fish to work with at young age. Tails are fused. As the fish grow in size, the tail is pushed forward into a forward curl. This development requires no current. The fish that are often entered in shows are not complete in tail fin development. The fish is largely red, white or red/white.


The head is pointed to slightly pointed. They typically have a head like the Ryukin, but can be slightly more rounded like that of a fantail.


The back of the fish has a slight rise, similar to a fantail. It does not have a hump like a Ryukin.


The tail is fused and resembles a Ryukin tail of medium length. The big difference is the bending forward scroll of the lead fin rays that has to match.

Other Fins

The other fins should be matched. No anal fins are not acceptable; one anal fin is acceptable.

The point schedule for a Tosakin is a 100 points.

Tail 50
Body 20
Head 10
Other Fins 10
Deportment and Condition 10


Tail has matched forward scroll as in the illustration 50
Tail scroll is incomplete 35-40
Tail is not held on an even plane when swimming or at rest 25-35
Tail is not fused Disqualified


Body is fantail-like with a very short peduncle, no hump but a slight rise 20
Body is as above, but out of proportion with the tail 10
Body has a slight bend to either side 5


Head is only slightly rounded or pointed, no head growth or pom poms 10
Headgrowth present Disqualified
Mouth turned down Disqualified

Other Fins: Other fins must be matched and not clamped, deduction of 5 to 10 points depending on severity.

Deportment and condition

The Tosakin has an extreme tail development, this development often causes issues with swimming and resting.

When swimming and at rest the fish does not list to one side 10
When swimming the fish move always to one side 5-7
When resting the fish lists to one side 5-8