Shiro Utsuri, essentially the most commonplace and common variety of the Utsurimono spouse and children, are koi by using a black foundation and regions of white sample overlaying the black. To transfer new koi to your aquarium, float them during the water inside of their bag for around 10 minutes https://titusoercm.nico-wiki.com/1389207/5_simple_statements_about_shiro_utsuri_koi_explained