Nishikigoi, better known as koi fish, are a well-known variety of the common carp. ... Thanks to selective breeding and an FGFR1 gene mutation, it lacks scales, so its skin is smooth.

Koi carp are one of the most iconic ornamental fish in the world. Originally hailing from Japan, these beautiful fish have amazingly patterned bodies. There are many varieties–– and some of them are ...

Koi fish, especially the Kohaku variety, are prized for their beauty, longevity, and breeding potential. Factors like bloodline, pattern, size, and gender influence their value, with females often ...

If the fish is an adult koi, it's a relatively small one, Cohen said. Koi can grow to be up to three feet, according to the Smithsonian's National Zoo and Conservation Biology Institute.

The nation’s top koi aficionados will bring their most spectacular fish — up to 3 feet long — to South San Jose to compete this weekend, April 5-6, in the ZNA NorCal National Koi Show.

Karner estimated the koi were six or seven years old based on an examination of scales under a microscope. One of the pre-spawn females contained an estimated 250,000 eggs.

Besides its long lineage, the unique color pattern of Taisho Sanshoku koi contributes to its high value. The most expensive one, a Maruten Sanke, fetched $341,990 at a Sakai Fish Farm auction in 2015.