These tubs are mixed Sanke and Showa
Once known as the Taisho Sanke, or Taisho Sanshuko, Koi of the Sanke variety look very much like Kohaku that have been spattered with ink. As a matter of fact, the two varieties, Sanke and Kohaku, are closely linked and are the only koi varieties with traceable bloodlines. Exactly when Sanke first appeared is open to debate, but it is known that a Sanke was first exhibited at the Tokyo Exhibition in 1914 by koi breeder Gonzo Hiroi. This would suggest that the variety may have been discovered in the late 1900s (which would place it in the Meiji era). Whether the Sanke was bred consciously or not is still unknown.