The Ranchu is what some Japanese enthusiast are known for calling the King of goldfish.
Japanese breeder think tanks discovered, through research and experimentation, this ranchu breed devised from the various lionhead goldfish variety stocks.
The descending arch of the ranchu is more pronounced than most other goldfish varieties and types.
This downward arch is definitely more pounced than the origin stocks or any of the lionhead breeds.
They remind you of shoulder muscles being flexed by children in the mirror to imitate body builders posing with dynamic tension.
Some of the other features that set these ranchu apart are that they have short tails, and a stomach area that takes up 5/8th to 3/4th of the fish.
They are more egg shaped than not. And they looked like a very bulked up body building version of the otherwise sleek goldfish.
This bulky look is also visually an effect of the fish simply not having a dorsal fin.
Ranchu look like the bald muscled version of this fish. It might be one of the reasons why the collective Japanese breeding eye sees them as the King of goldfish.
Most ranchu come in orange, black and gray.
And indeed they look like the sumo of goldfish.
In fact the bramble heads on the head of the ranchu support this likeness well beyond that of an aquarist writers initial assumptions.
Many people the world over see this same correlation.
The bramble-heads remind many breeders and breeding societies world wide of the funny hairdos of sumo wrestlers. This further adds to the comparison.
The ranchu is considered strong, yet out of shape do to fatness, as are the respected sumo.
Both the sumo and the ranchu represent traditional thoughts on esthetic.
Size, in balance will impose realities of massive circles and squares. This is viewed as a strong attribute of both the ranchu and the sumo as they move with proportional harmony will graceful force.