Shiro Utsuri, by far the most common and well-liked variety of the Utsurimono relatives, are koi which has a black base and parts of white pattern overlaying the black. To transfer new koi for the aquarium, float them while in the drinking water inside their bag for about ten minutes https://shiro-utsuri-koi63962.ja-blog.com/34620208/shiro-utsuri-koi-no-further-a-mystery