Doitsu koi are a variety bred in Germany. “Doitsu” is a derivative of the word “German” in Japanese. These koi are distinguished by having minimal or no scales. They may just have a zipper of scales along their lateral line or dorsal fin, a few speckled here and there, or no scales at all.
These fish can be very confusing to a new koi enthusiast. Without the overlying scales to protect each other, Doitsu koi may lose a scale occasionally and have large blemishes in their skin. There is nothing sickly about these fish, they are just bred to a different standard than other koi. In a pond with good water, these holes will heal up quickly with no damage to the fish.
Doitsu are also more prone to injury when they are flashing, or itching themselves, with any parasite infection. Some Doitsu koi are good show fish, specifically the Asagi, but they do not win any top prizes.